what is meant by the term standard conditions, with reference to enthalpy changes? p = 1 atm , t = 0 k . p = 1 atm , t = 273 k . p = 1 kpa , t = 273 k . p = 1 atm , t = 298 k .

Answers

Answer 1

The main answer to your question is that standard conditions refer to a set of specific conditions used as a reference point for enthalpy changes.

These conditions include a pressure of 1 atm and a temperature of either 0 K, 273 K, or 298 K, depending on the context.
To give an explanation, enthalpy changes are often measured in relation to a standard set of conditions to provide a consistent basis for comparison.

The pressure and temperature values used for standard conditions are chosen because they are common and easily reproducible.



A summary of the answer is that standard conditions refer to a set of predetermined pressure and temperature values that are used as a reference point for enthalpy changes. These conditions are chosen because they are commonly used and easily reproducible.

learn more about temperature click here:

https://brainly.com/question/24746268

#SPJ11


Related Questions

when nh4no3 dissolves in water, the temperature of the solution decreases. what describes the enthalpy and entropy changes of the system and which change drives the process? (a) delta h

Answers

When [tex]NH_4NO_3[/tex] dissolves in water, the enthalpy of the system decreases, and the entropy of the system increases. The increase in entropy is the driving force of the process, causing the solute to dissolve in the solvent. Option A is the correct answer.

When [tex]NH_4NO_3[/tex] dissolves in water, it undergoes an endothermic process in which heat is absorbed from the surroundings, causing the temperature of the solution to decrease. This suggests that the dissolution process is driven by an increase in the system's entropy, rather than by a decrease in enthalpy.

The enthalpy change of the system can be determined by measuring the heat of the solution, which is the amount of heat absorbed or released when a solute dissolves in a solvent. In the case of [tex]NH_4NO_3[/tex], the heat of the solution is positive, indicating an endothermic process in which heat is absorbed. This means that the enthalpy of the system decreases when [tex]NH_4NO_3[/tex] dissolves in water.

The entropy change of the system can be determined by calculating the difference in the entropy of the solution and the sum of the entropies of the separate components (the solute and the solvent) before mixing. In the case of [tex]NH_4NO_3[/tex] dissolving in water, the increase in the disorder of the system is driven by the release of ammonium ions and nitrate ions into the solvent. The disorder of the system increases because the ions become more dispersed and move around freely in the solution. This increase in entropy is the driving force of the process.

To learn more about enthalpy

https://brainly.com/question/16720480

#SPJ4

Complete question:

Which of the following describes the enthalpy and entropy changes of the system when [tex]NH_4NO_3[/tex] dissolves in water, and which change drives the process?

a) Enthalpy decreases and entropy increases; entropy change drives the process

b) Enthalpy increases and entropy decreases; enthalpy change drives the process

c) Enthalpy decreases and entropy decreases; enthalpy change drives the process

d) Enthalpy increases and entropy increases; entropy change drives the process

the ka for formic acid (hcooh) is 1.8 x 10-4 . what is the ph of a 0.15 m aqueous solution of sodium formate (nahcoo)? group of answer choices 5.54 11.64 8.46 3.39 4.26

Answers

The correct option is C, The pH of the 0.15 M aqueous solution of sodium formate is 8.46.

The chemical equation for the reaction between formic acid and sodium formate is:

HCOOH + NaHCOO ⟷ HCOO⁻ + Na⁺ + H₂O

Ka = [H⁺][HCOO⁻] / [HCOOH]

[H⁺] = Ka x [HCOOH] / [HCOO⁻]

[H⁺] = (1.8 x [tex]10^{-4[/tex]) x (0.15) / 1

[H⁺] = 2.7 x [tex]10^{-5[/tex] M

pH = 14 - pOH

pH = 14 - (-log[OH⁻])

pH = 14 - (-log Kw / [OH⁻])

pH = 14 - (-log Kw - log [OH⁻])

pH = 14 - (14 + pKw - pOH)

pH = pKw - pOH

pH = 14 - 1/2(pKa - log [NaHCOO])

where pKw = 14, and pKa = -log Ka = -log (1.8 x [tex]10^{-4[/tex]) = 3.74.

Substituting the values into the equation gives:

pH = 14 - 1/2(3.74 - log 0.15)

pH = 8.46

pH is a measure of the acidity or basicity of a solution. The pH scale ranges from 0 to 14, with 0 being the most acidic, 7 being neutral, and 14 being the most basic (also called alkaline). The pH of a solution is determined by the concentration of hydrogen ions (H+) in the solution. The more hydrogen ions there are, the lower the pH and the more acidic the solution is. Conversely, the fewer hydrogen ions there are, the higher the pH and the more basic the solution is.

The pH of a solution can be measured using a pH meter or by using pH paper, which changes color depending on the pH of the solution. It is important to control the pH of certain chemical reactions and processes, as it can affect the rate of reaction and the properties of the resulting product.

To know more about pH refer to-

brainly.com/question/2288405

#SPJ4

at what temperature does a perfect crystalline solid have δs=0?

Answers

For a perfect crystalline solid, the third law of thermodynamics states that the entropy of a perfectly crystalline substance at absolute zero temperature is zero.

This is because at absolute zero temperature, all substances are in their lowest possible energy state, which corresponds to a perfect crystal with no disorder or entropy.

Therefore, the temperature at which a perfect crystalline solid has zero entropy (ΔS = 0) is absolute zero, which is 0 Kelvin or -273.15 degrees Celsius. However, reaching absolute zero is theoretically impossible, so in practice, the entropy of a crystalline solid will never be exactly zero.

Learn more about solid here:

https://brainly.com/question/17061172

#SPJ11

A 1.43-g sample of an unknown pure gas occupies a volume of 0.333 L at a pressure of 1.00 atm and a temperature of 100.0°C. The unknown gas is?

Answers

To determine the identity of the unknown gas, we can use the ideal gas law, which relates the pressure, volume, temperature, and amount (in moles) of a gas:

PV = nRT

where P is the pressure, V is the volume, n is the amount of gas in moles, R is the ideal gas constant, and T is the temperature in Kelvin.

First, we need to convert the temperature to Kelvin:

T = 100.0°C + 273.15 = 373.15 K

Next, we can calculate the amount of gas in moles using the given mass and the molar mass of the unknown gas:

n = m/M

where m is the mass of the gas and M is the molar mass of the gas.

To find the molar mass of the unknown gas, we can rearrange the ideal gas law to solve for the molar mass:

M = mRT/PV

Substituting in the given values, we get:

M = (1.43 g)(0.0821 L·atm/K·mol)(373.15 K)/(1.00 atm)(0.333 L) = 57.9 g/mol

Now we can use the molar mass to identify the unknown gas. Comparing the molar mass to the periodic table, we find that the closest match is nitrogen gas (N2), which has a molar mass of 28.0 g/mol. However, the molar mass we calculated is twice as large as this value, suggesting that the unknown gas is actually a diatomic molecule with twice the mass of nitrogen. This suggests that the unknown gas is oxygen gas (O2), which has a molar mass of 32.0 g/mol.

Therefore, the unknown gas is most likely oxygen gas (O2).

Learn more about gas here:

https://brainly.com/question/3637358

#SPJ11

write the chemical equation describing the complete combustion of liquid octane, c8h18.

Answers

[tex]C_{8} H_{18} + 12.5O_{2}[/tex] → [tex]8CO_{2} + 9H_{2} O[/tex] is the balanced chemical equation for the complete combustion of liquid octane.

The complete start of liquid octane ([tex]C_{8} H_{18}[/tex]) incorporates answering it with oxygen ([tex]O_{2}[/tex]) to make carbon dioxide ([tex]CO_{2}[/tex]) and water ([tex]H_{2} O[/tex]). The sensible engineered condition for this reaction is:

[tex]C_{8} H_{18} + 12.5O_{2}[/tex] → [tex]8CO_{2} + 9H_{2} O[/tex]

This condition shows that one molecule of liquid octane answers with 12.5 particles of oxygen to make eight particles of carbon dioxide and nine iotas of water. The coefficient of 12.5 before the [tex]O_{2}[/tex] shows that the extent of octane to oxygen is 1:12.5, and that suggests that a ton of oxygen is supposed for complete consuming to occur.

The start of octane is an exothermic reaction, inferring that it releases force and energy. This reaction is similarly responsible for filling internal combustion engines in vehicles, where liquid octane is singed in a controlled environment to convey energy for the engine to run.

In frame, the complete start of liquid octane achieves the production of carbon dioxide and water, as shown in the fair substance condition [tex]C_{8} H_{18} + 12.5O_{2}[/tex] → [tex]8CO_{2} + 9H_{2} O[/tex].

To learn more about combustion of octane, refer:

https://brainly.com/question/30934906

#SPJ1

does 1 action potential trigger enough glutamate to be released so that ltp happens?

Answers

While one action potential can trigger some glutamate release, it is not sufficient to induce LTP.

An action potential is the electrical impulse that travels down a neuron and triggers the release of neurotransmitters, such as glutamate, at the synapse. The amount of glutamate released depends on various factors, such as the number of vesicles containing glutamate, the number of active zones on the presynaptic membrane, and the strength of the synapse.

However, in general, one action potential may not be enough to trigger enough glutamate release to induce long-term potentiation (LTP), which is a persistent strengthening of the synapse that underlies learning and memory. LTP requires sustained and repetitive stimulation of the synapse, often referred to as high-frequency stimulation (HFS), which can induce a series of action potentials that lead to a massive release of glutamate and activation of postsynaptic receptors. This can trigger various intracellular signaling pathways that enhance synaptic efficacy and produce lasting changes in the strength of the synapse.

Therefore, while one action potential can trigger some glutamate release, it is not sufficient to induce LTP.

Know more about glutamate here,

https://brainly.com/question/10089303

#SPJ11

the cs-131 nuclide has a half-life of 30 years. after 120 years, 6.0 g remain. what is the original mass of the cs-131 sample in grams?

Answers

Answer:

The half-life of a radioactive substance is the time it takes for half of the substance to decay. In this case, the half-life of Cs-131 is 30 years. After 120 years, which is equivalent to four half-lives (120 years / 30 years/half-life = 4 half-lives), the original mass of Cs-131 would have been halved four times.

Let’s say the original mass of the Cs-131 sample is M. After one half-life, the remaining mass would be M/2. After two half-lives, the remaining mass would be (M/2)/2 = M/4. After three half-lives, the remaining mass would be (M/4)/2 = M/8. And after four half-lives, the remaining mass would be (M/8)/2 = M/16.

Since we know that after four half-lives (120 years), 6.0 g of Cs-131 remain, we can set up an equation to solve for the original mass M: M/16 = 6.0 g. Solving for M, we find that M = 16 * 6.0 g = 96 g.

Therefore, the original mass of the Cs-131 sample was 96 grams.

Explanation:

why does the benzaldehyde starting material not form an enolate

Answers

Benzaldehyde does not form an enolate because it lacks an alpha-hydrogen, which is essential for enolate formation. In most carbonyl compounds, the alpha-hydrogen is adjacent to the carbonyl group (C=O) and can be deprotonated by a strong base.

This deprotonation leads to the formation of an enolate ion, which is stabilized by resonance with the carbonyl group. However, in the case of benzaldehyde, the carbonyl group is directly attached to a benzene ring. The alpha position does not have a hydrogen atom but rather, it is connected to the aromatic ring. Since there is no alpha-hydrogen to deprotonate, benzaldehyde cannot form an enolate. This characteristic of benzaldehyde makes it behave differently in reactions compared to other carbonyl compounds, such as aldehydes and ketones. It is important to consider the absence of an alpha-hydrogen in benzaldehyde when predicting or analyzing its reactivity in various chemical reactions.

To know more about Benzaldehyde

https://brainly.com/question/30230005

#SPJ11

which substance is the least soluble in h2o? (a) k2co3 (b) khco3 (c) ca(hco3)2 (d) caco

Answers

Of the options given, the least soluble substance in [tex]H_{2}O[/tex]is [tex]CaCO_{3}[/tex].

The correct option is (d) [tex]CaCO_{3}[/tex].

This is because [tex]CaCO_{3}[/tex].. is a sparingly soluble salt, meaning that only a small amount of it will dissolve in water. [tex]K_{2}CO_{3}[/tex] and [tex]KHCO_{3}[/tex] are both highly soluble in water, as they are both salts of strong bases and strong acids. [tex]Ca(HCO_{3})_{2}[/tex] is also relatively soluble in water, as it is a salt of a weak base [tex](Ca(OH)_{2} )[/tex] and a weak acid [tex](H_{2}CO_{3})[/tex] However, it is still more soluble than [tex]CaCO_{3}[/tex]. Solubility of a substance depends on several factors, including the nature of the solute and solvent, temperature, pressure, and concentration. Generally, the solubility of a substance increases with temperature and decreases with pressure, but this is not always the case. In summary, [tex]CaCO_{3}[/tex]. is the least soluble substance in [tex]H_{2}O[/tex] among the given options.

Learn more about soluble here:

https://brainly.com/question/29857840

#SPJ11

The complete question is:

which substance is the least soluble in [tex]H_{2}O[/tex]? (a)  [tex]K_{2}CO_{3}[/tex] (b) [tex]KHCO_{3}[/tex]  (c) [tex]Ca(HCO_{3})_{2}[/tex] (d) [tex]CaCO_{3}[/tex].

write the oxidation state for the underlined element in the box following each compound. a) [reo4 ] −

Answers

For the compound [ReO4]−, the oxidation state of the underlined element Re (Rhenium) is +7.

The oxidation state, also known as oxidation number, represents the hypothetical charge an atom would have if all its bonds were ionic. In the compound [ReO4]−, Re (Rhenium) is the underlined element. Each oxygen atom has an oxidation state of -2. Since there are four oxygen atoms, the total oxidation state for oxygen in this compound is -8 (-2 x 4). The overall charge of the compound is -1. To find the oxidation state of Re, we need to balance the equation:

Re + 4(-2) = -1

Re - 8 = -1

Re = +7

Thus, the oxidation state of the underlined element Re (Rhenium) in the compound [ReO4]− is +7.

To know more about the oxidation state visit:

https://brainly.com/question/11313964

#SPJ11

which is the best description of molecules that are geometric stereoisomers

Answers

Geometric stereoisomers, also known as cis-trans or E-Z isomers, are a type of isomer that differ in their spatial arrangement around a double bond or rigid ring structure. These molecules have the same molecular formula and connectivity, but their distinct configurations result in different chemical and physical properties.

In geometric isomerism, the key factor is the restricted rotation around the double bond or ring, which prevents free interconversion between the isomers.

Cis isomers are characterized by similar groups situated on the same side of the double bond or ring, while trans isomers have these groups on opposite sides. In the E-Z nomenclature, E (entgegen) refers to the isomer with the two highest priority substituents on opposite sides, and Z (zusammen) to the one with these groups on the same side.

Geometric stereoisomers are particularly significant in the field of organic chemistry, as they often exhibit varying reactivity, stability, and biological activity.

You can learn more about stereoisomers at: brainly.com/question/31147524

#SPJ11

when the salt naf dissolves in water, the ph of the solution is greater than 7. why is the ph greater than 7?

Answers

When the salt NaF dissolves in water, the pH of the resulting solution is greater than 7 because the fluoride ion (F-) derived from NaF undergoes hydrolysis, resulting in the formation of hydroxide ions (OH-) and a basic solution.

The hydrolysis of F- occurs because it is the conjugate base of a weak acid, HF. When F- reacts with water, it attracts a proton from water, forming HF and OH- ions. The OH- ions contribute to the concentration of hydroxide ions in the solution, leading to an increase in pH.

The hydrolysis reaction can be represented as follows:

F- + H2O ⇌ HF + OH-

Since hydroxide ions (OH-) are formed in the process, they increase the concentration of hydroxide ions in the solution, which in turn raises the pH above 7. The extent of hydrolysis and the resulting pH will depend on the concentration of NaF and the temperature of the solution.

Therefore, when NaF dissolves in water, the pH of the solution is greater than 7 due to the hydrolysis of the fluoride ion, resulting in the production of hydroxide ions.

Know more about Basic Solution here:

https://brainly.com/question/3449428

#SPJ11

Write and balance the following single
replacement reaction.
e) Cu + H₂SO4 →

Answers

Answer:

The balanced chemical equation for the single replacement reaction between copper (Cu) and sulfuric acid (H₂SO4) is:

Cu + H₂SO4 → CuSO4 + H2

Explanation:

In this reaction, copper reacts with sulfuric acid to form copper(II) sulfate and hydrogen gas. The copper replaces the hydrogen in the sulfuric acid compound, resulting in the formation of copper(II) sulfate and hydrogen gas. The equation is balanced because there are equal numbers of atoms of each element on both sides of the arrow.

If the temperature of 50.0 L of a gas at 40.0°C falls by 10.0C°, what is the new volume of the gas if the pressure is constant?
a. 45.0 L
b.48.4 L
c.52.0 L
d.55.0 L ​

Answers

48.4– hope that helped.

Octane (molar mass 114.23 g/mol) evaporates into a space ata a rate of 2.2. milligrams per minute where the ventilation rate is 80 m^3/min. Assuming nonideal mixing, a temperature of 300 K and atmospheric pressure, estimate the concentration of octane vapor. Does it exceed the TLV of 300 ppm?
The three answer selections are:
1. Yes, in this example, the TLV of octane will be exceeded.
2. No, in this example, the TLV of octane will not be exceeded.
3. Not enough information to determine if the TLV will be exceeded or not.

Answers

Based on the given information, the concentration of octane vapor can be estimated using the formula: concentration (in ppm) = (evaporation rate in mg/min) / (ventilation rate in m^3/min) * (24.45 / molar mass in g/mol). Plugging in the values, we get concentration = (2.2 / 80) * (24.45 / 114.23) * 10^6 = 104.6 ppm. This concentration does not exceed the TLV of 300 ppm.

Therefore, the answer is 2. No, in this example, the TLV of octane will not be exceeded.
In this example, the concentration of octane vapor can be estimated as follows:
First, convert the evaporation rate to moles/min:
2.2 mg/min * (1 g/1000 mg) * (1 mol/114.23 g) = 0.00001925 mol/min

Next, calculate the concentration in ppm using the ventilation rate:
(0.00001925 mol/min) / (80 m^3/min) * (1,000,000 ppm/1 mol) = 0.240625 ppm
The estimated concentration of octane vapor is 0.240625 ppm. Comparing this to the TLV of 300 ppm, we can conclude that in this example, the TLV of octane will not be exceeded (option 2).

To know more about pressure visit-

https://brainly.com/question/12971272

#SPJ11

The risk-free rate is 5% and the dividend yield on an index is 2%. Which of the following isthe delta with respect to the index for a one-year futures on the index?A.0.98B.1.05C.1.03D.1.02

Answers

The delta with respect to the index for a one-year futures on the index is approximately 1.03

The delta is a measure of the sensitivity of the futures contract price to changes in the underlying asset. In this case, the underlying asset is an index and we need to calculate the delta for a one-year futures contract on the index.

The delta with respect to the index for a one-year futures on the index can be calculated using the risk-free rate and the dividend yield. In this case, the risk-free rate is 5% and the dividend yield is 2%. To find the delta, you would use the following formula:

Delta = (1 + Risk-free rate) / (1 + Dividend yield)

Plugging in the given values, we get:

Delta = (1 + 0.05) / (1 + 0.02)

Delta = 1.05 / 1.02

Delta ≈ 1.03

Therefore, the delta with respect to the index for a one-year futures on the index is approximately 1.03, which corresponds to option C in your question.

Learn more about index here,

https://brainly.com/question/24275900

#SPJ11

glass is:a supercooled liquid whose viscosity is so high is behaves like a solid.a covalent network solid.a solid crystalling material constructed of two or more different kinds of other materials.a nonmetallic solid produced at high temperatures.a metallic solid produced at high temperature.

Answers

glass is: a supercooled liquid whose viscosity is so high is behaves like a solid

What makes glass a super-cooled liquid, and why?

In essence, glass is an amorphous solid. It does not take the shape of crystals. The glass's component parts can therefore move. Under normal circumstances, the component particles of ordinary solids do not move. Glass is sometimes referred to as a supercooled liquid because of its fluidity. It is possible to think of glass as a very viscous liquid. The windows' gradual increase in bottom thickness serves as visual proof of the claim.

Glass is an amorphous solid that is widely used in window panes, dinnerware, and optics for practical, technical, and ornamental purposes1. It is typically clear or translucent as well as hard, brittle, and resistant to the environment. Glasses are created by rapidly cooling molten components, such as silica sand so that no apparent crystals develop. They do not have crystalline internal structures.

learn more about Glass.

https://brainly.com/question/31666746

#SPJ4

Write and balance the following single
replacement reaction.
g) Ca + H₂O (steam)

Answers

The balanced equation for this single replacement reaction is Ca + 2H₂O → Ca(OH)₂ + H₂.

The products like Calcium (Ca) and water (H₂O) are reacting with each other and they are balanced by using the appropriate coefficient. When calcium interacts with water, it goes through an oxidation process that removes the hydrogen from the reduced water molecule.

The reaction is a single replacement reaction because as we can see, the ions of one of the species in the products are changed only. About the balancing part, we have to make sure that the reaction follow the law of conservation of mass.

To know more about single replacement reaction, visit,

https://brainly.com/question/28909116

#SPJ1

which of the following pairs of substances would make the best buffer with a basic ph? ka for hc3h2o2

Answers

To determine the best buffer with a basic pH using the given pKa value for HC3H2O2, we need to find a pair of substances where one acts as a weak acid (HC3H2O2) and the other as its conjugate base (C3H2O2-).

The pKa of HC3H2O2 represents the pH at which the acid is 50% ionized. Since we want a basic pH, we need a pKa value that is slightly higher than the desired pH. Let's assume the desired pH is around 9.

A quick calculation shows that a pKa of 8.5 would be suitable for our purpose.

Now, we need to find a conjugate base with a pKa close to 8.5. One example is ammonium acetate (NH4C2H3O2) with a pKa of 9.25. When ammonium acetate is dissolved in water, it dissociates into NH4+ (conjugate acid) and C2H3O2- (conjugate base).

Therefore, the best buffer pair for a basic pH would be HC3H2O2 (acetic acid) and NH4C2H3O2 (ammonium acetate).

The pKa value of HC3H2O2 is not provided in the question. However, assuming we have the pKa value of HC3H2O2, we can use it to calculate the pH range over which the buffer will be effective.

The Henderson-Hasselbalch equation is commonly used to calculate the pH of a buffer solution:

pH = pKa + log ([A-]/[HA])

In this equation, [A-] represents the concentration of the conjugate base, and [HA] represents the concentration of the weak acid.

To create a buffer with a basic pH, we need a pKa slightly higher than the desired pH. Assuming a desired pH of 9, we can use a pKa value around 8.5.

Let's consider ammonium acetate (NH4C2H3O2) as a potential conjugate base for HC3H2O2. The pKa value of ammonium acetate is 9.25.

Using the Henderson-Hasselbalch equation, we can determine the pH range over which the buffer will be effective. For a basic pH, we want the [A-]/[HA] ratio to be high, indicating a significant concentration of the conjugate base.

With a pKa of 8.5 for HC3H2O2 and a pKa of 9.25 for NH4C2H3O2, we can calculate the pH range as follows:

pH = pKa + log ([A-]/[HA])

pH = 8.5 + log ([C2H3O2-]/[HC3H2O2])

To ensure a high [C2H3O2-]/[HC3H2O2] ratio, we can adjust the concentrations of the weak acid and its conjugate base accordingly. By choosing appropriate concentrations, we can achieve a pH in the desired range.

Based on the given pKa value for HC3H2O2, the best buffer pair for a basic pH would be HC3H2O2 (acetic acid) and NH4C2H3O2 (ammonium acetate) with a pKa of 8.5 for HC3H2O2 and a pKa of 9.25 for NH4C2H3O2. By adjusting the concentrations of the weak acid and its conjugate base

To know more about best buffer and basic pH, Visit,

brainly.com/question/24262133

#SPJ11

The following list contains some common polyatomic ions. Using the charge on these ions and the idea of valence, predict the formulas for the compound formed from the following:


nitrate NO3-1 phosphate PO4-3

sulfate SO4-2 acetate C2H3O2-1

ammonium NH4+1 chromate CrO4-2

carbonate CO3-2 dichromate Cr2O7-2

permanganate MnO4-1 sulfite SO3-2

ammonium and sulfite


A. (NH 4) 2SO 3

B. NH 4SO 4

C. (NH 4) 2SO 4

D. NH 4SO 3

Answers

When given polyatomic ions such as nitrate, phosphate, sulfate, acetate, ammonium, chromate, carbonate, dichromate, and permanganate with a charge, valency can be used to predict the formulae for the compounds formed. The formula for ammonium and sulfite is NH₄SO₃. The correct option is D. NH₄SO₃.

Valency is the measure of an atom's combining power with other atoms when it comes to forming chemical compounds or molecules. A compound's valency is determined by the number of electrons required by an atom to reach the noble gas electronic configuration. Therefore, the valency of an element is either positive or negative. The valency of polyatomic ions is the charge present on the ion.

The formula of a compound formed between a metal and a polyatomic ion is determined by the valency of the polyatomic ion and the valency of the metal. When forming a compound between a metal and a polyatomic ion, it is vital to remember that the net charge of the compound should always be zero. For example, NH₄⁺¹ and SO₃⁻² combine to form NH₄SO₃. Hence, D is the correct option.

You can learn more about polyatomic ions at: brainly.com/question/6689894

#SPJ11

what is the energy of an incident photon that is just enough to excite a hydrogen atom from its ground state to its n

Answers

The energy of an incident photon that is just enough to excite a hydrogen atom from its ground state to its n = 150 excited state is approximately 13.6 eV.

The energy of an incident photon that is just enough to excite a hydrogen atom from its ground state to its nth energy level (n > 1) can be calculated using the formula:

[tex]$E = -\frac{13.6 \text{ eV}}{n^2} + 13.6 \text{ eV}$[/tex]

where E is the energy of the photon and n is the energy level of the excited state.

For n = 2 (i.e., first excited state), the energy of the photon required would be:

[tex]$E = -\frac{13.6 \text{ eV}}{2^2} + 13.6 \text{ eV}$[/tex]

= -3.4 eV + 13.6 eV

= 10.2 eV

For n = 150, the energy of the photon required would be:

[tex]$E = -\frac{13.6 \text{ eV}}{150^2} + 13.6 \text{ eV}$[/tex]

= -0.00006 eV + 13.6 eV

= 13.6 eV (approx.)

To learn more about photon

https://brainly.com/question/29413875

#SPJ4

what is the percent composition of nitrogen in ammonium phosphide

Answers

Answer:

Explanation:

28.18

This was right for me, it may differ for you.

for each reaction you perform, you will mix together 50.0 ml of 2.00 m acid and 2.00 m base. what are the resulting concentrations of the reactants upon mixing?

Answers

The resulting concentration of the base will also be 2.00 M, assuming complete neutralization.

When mixing an acid and a base, a neutralization reaction occurs, resulting in the formation of a salt and water. The resulting solution will contain only the conjugate base of the acid and the conjugate acid of the base, along with any excess acid or base that was not neutralized.

Assuming complete neutralization, the moles of acid and base will be equal in the mixture. The volume of the mixture is 100.0 mL, so we can use the following equation to calculate the resulting concentrations of the reactants:

moles of acid = moles of base

M(acid) x V(acid) = M(base) x V(base)

Substituting the given values:

2.00 M x 50.0 mL = M(base) x 50.0 mL

M(base) = 2.00 M

Any excess acid or base will be present in smaller concentrations.

To learn more about concentrations click on,

https://brainly.com/question/31429013

#SPJ4

in the reaction, zn 2 hcl zncl2 h2, 25.0 grams of zn are reacted with 17.5 g of hcl. how many grams of h2 will be produced?

Answers

In the reaction between zinc (Zn) and hydrochloric acid (HCl) to form zinc chloride (ZnCl2) and hydrogen gas (H2), 25.0 grams of Zn and 17.5 grams of HCl are reacted. We need to determine the mass of H2 produced in the reaction.

To find the mass of H2 produced, we need to determine the limiting reactant. To do this, we calculate the moles of each reactant by dividing their masses by their respective molar masses.

The balanced chemical equation tells us that the stoichiometric ratio between Zn and H2 is 1:1. However, in order to compare the two reactants, we need to consider the stoichiometric ratio between Zn and HCl. By using the molar masses and stoichiometry, we find that 65.38 grams of Zn reacts with 36.46 grams of HCl.

Comparing the actual masses of Zn (25.0 grams) and HCl (17.5 grams), we see that HCl is the limiting reactant. This means that all of the HCl will be consumed, and the amount of H2 produced will be determined by the stoichiometry of the reaction.

Using the stoichiometry, we find that 1 mole of HCl produces 1 mole of H2. Therefore, the moles of H2 produced will be equal to the moles of HCl. Finally, we can calculate the mass of H2 by multiplying the moles of H2 by its molar mass.

By performing these calculations, we can determine the mass of H2 produced when 25.0 grams of Zn reacts with 17.5 grams of HCl.

Learn more about reaction here:

https://brainly.com/question/14025220

#SPJ11

f a bar of silver is covered with of silver tarnish, what amount (in ) of silver atoms was either oxidized or reduced? the molar mass of is . report the answer to 3 significant figures.

Answers

Bar's silver atoms are oxidized to create silver tarnish. Silver moles tarnish. (Ag₂S) will oxidised = 0.0412 mol

Bar's silver atoms are oxidized to create silver tarnish. Silver moles tarnish. (Ag₂S)

5.11 g ÷247-8 g/mol = 0.0206 mol

1 mol Ag₂s is formed from 2 mol Ag.

Hence , the total silver (Ag) atoms gets oxidised.

2 × 0.0206 mol

Moles of Ag oxidised is  = 0.0412 mol

2.) Solving Oxidation half: Ag For 1 mol Ag,

1 mol e- Ag⁺ are transferred

Electrons transferred. 0412 mol

What is the significance of oxidation and reduction?

Redox reactions, or oxidation-reduction reactions, are important because they are the main sources of natural or artificial energy on this planet. By removing hydrogen and replacing it with oxygen, oxidation of molecules typically results in the release of a significant amount of energy.

What is the oxidation-decrease process?

The substance that gives electrons is oxidized by it. Because iron has been oxidized (the iron has lost some electrons) and oxygen has been reduced (the oxygen has gained some electrons), it reacts with oxygen to form rust, a chemical. Oxidation is the cause of reduction.

Incomplete question :

Silver Tarnish II 0.0/2.0 points (graded) If a bar of silver is covered with 5.11 g of silver tarnish, what amount (in mol) of silver atoms was either oxidized or reduced? The molar mass of Ag2S is 247.8 mol What amount (in mol) of electrons were transferred?

Learn more about oxidation :

brainly.com/question/13182308

#SPJ4

Experimental Data Sheet Х Zn (9) 1.9887 Zn: Pressure of H2 (torr) 1140.0 Mass Unknown 1 (9) 5.0030 PH2 Unknown 1 (torr). 3372.7 Mass Unknown 2 (9) 5.0172 P H2 Unknown 2 (torr). 2014.7 First, the data from the Zn metal reagent will be used to determine the volume of the pressure vessel. Using the Zn sample mass, calculate the number of moles of Zn (m) used in the reaction and enter below. moles Zn

Answers

We were only asked to calculate the moles of zinc, the answer is simply:

moles Zn = 0.0304 mol

The given experimental data can be used to calculate the number of moles of hydrogen gas produced in the reaction with zinc.

To do so, we need to use the ideal gas law: PV = nRT, where P is the pressure of the gas, V is the volume of the container, n is the number of moles of the gas, R is the gas constant, and T is the temperature.

First, we need to calculate the volume of the container using the data for zinc metal. From the given data, we know that the mass of zinc used in the reaction is 1.9887 g. Using the molar mass of zinc (65.38 g/mol), we can calculate the number of moles of zinc:

moles Zn = 1.9887 g / 65.38 g/mol = 0.0304 mol

Next, we can use the pressure of hydrogen gas and the mass of the unknown sample to calculate the number of moles of hydrogen produced. We can assume that the volume of the container is the same for both unknown samples:

n = PV/RT = (P x V)/(R x T)

For unknown sample 1, we have:

n = (3372.7 torr x V)/(62.3637 L•torr/mol•K x 298 K)

For unknown sample 2, we have:

n = (2014.7 torr x V)/(62.3637 L•torr/mol•K x 298 K)

We can solve for V by setting the two expressions equal to each other:

(3372.7 torr x V)/(62.3637 L•torr/mol•K x 298 K) = (2014.7 torr x V)/(62.3637 L•torr/mol•K x 298 K)

Solving for V, we get V = 1.995 L

Finally, we can use the moles of hydrogen and the mass of the unknown sample to calculate the molar mass of the unknown compound. However, since we were only asked to calculate the moles of zinc, the answer is simply:

moles Zn = 0.0304 mol

Learn more about moles here:

https://brainly.com/question/31597231

#SPJ11

if a mass of 92.4 grams of zinc metal reacts with 62.3 grams of oxygen gas, what is the theoretical yield of zinc oxide formed in the reaction?

Answers

If a mass of 92.4 grams of zinc metal reacts with 62.3 grams of oxygen gas, the theoretical yield of zinc oxide formed in the reaction is 634.76 g.

The molar mass of zinc (Zn) is 65.38 g/mol. So, the number of moles (n) of Zn present in 92.4 g of mass is calculated as:

n = 92.4 / 65.38 = 1.41 moles

The molar mass of oxygen (O₂) is 16 g/mol. So, the number of moles (n) of O present in 62.3 g of mass is calculated as:

n = 62.3 / 16 = 3.9 moles

According to the balanced chemical reaction 1 mole of oxygen gives 2 moles of ZnO. So, 3.9 moles OF oxygen produces X mol of ZnO.

X = 2 × 3.9 = 7.8 mol

The molar mass of ZnO is 81.38 g/mol. So, the mass of 7.8 mol of ZnO is calculated as,

m = 7.8 × 81.38 = 634.764 g

Hence, the theoretical yield is 634.76 g.

Learn more about theoretical yield from the link given below.

https://brainly.com/question/14966377

#SPJ4

Balance each of the following redox reactions occurring in acidic aqueous solution. Express your answer as a chemical equation. Identify all of the phases in your answer.1.) K(s)+Al3+(aq)→Al(s)+K+(aq)2.) Cr(s)+Co2+(aq)→Cr3+(aq)+Co(s)3.) IO3−(aq)+N2H4(g)→I−(aq)+N2(g)

Answers

The balanced equations are as follows:

1.) 2K(s) + 2Al³⁺(aq) → 2Al(s) + 2K⁺(aq)

2.) 6Cr(s) + 14H+(aq) + 6Co²⁺(aq) → 6Cr³⁺(aq) + 6Co(s) + 7H₂O(l)

3.) 8IO₃⁻(aq) + N₂H₄(g) + 10H⁺(aq) → 5I⁻(aq) + N₂(g) + 12H₂O(l)

1.) In this redox reaction, potassium (K) is oxidized to potassium ions (K⁺) while aluminum ions (Al³⁺) are reduced to aluminum (Al). The balanced equation is obtained by ensuring that the number of electrons lost in oxidation (K) is equal to the number of electrons gained in reduction (Al).

2.) This reaction involves the oxidation of chromium (Cr) to chromium ions (Cr³⁺) and the reduction of cobalt ions (Co²⁺) to cobalt (Co). To balance the equation, it is necessary to balance the atoms and the charges, making sure that the number of electrons lost in oxidation (Cr) is equal to the number of electrons gained in reduction (Co).

3.) In this reaction, iodate ions (IO³⁻) are reduced to iodide ions (I⁻) while nitrogen hydrazine (N₂H₄) is oxidized to nitrogen gas (N₂). Balancing the equation involves ensuring that the number of electrons lost in oxidation (N₂H₄) is equal to the number of electrons gained in reduction (IO₃⁻).

Phases are indicated in parentheses, where (s) represents solid, (aq) represents aqueous, (g) represents gas, and (l) represents liquid.

To learn more about redox reactions, here

https://brainly.com/question/28300253

#SPJ4

what is the molarity of 30.0 ml of a nicl2 solution that reacts completely with 13.4 ml of a 0.280 m naoh solution?

Answers

The molarity of NiCl₂ in the solution is approximately 0.0625 moles per liter.

How to calculate molarity of NICl₂ solution?

To determine the molarity of the NiCl₂ solution, we can use the concept of stoichiometry and the volume of the NaOH solution used in the reaction.

Given information:

Volume of NiCl₂ solution = 30.0 mL

Volume of NaOH solution = 13.4 mL

Molarity of NaOH solution = 0.280 M

The balanced chemical equation for the reaction between NiCl₂ and NaOH is:

NiCl₂ + 2NaOH -> Ni(OH)₂ + 2NaCl

From the balanced equation, we can see that one mole of NiCl₂ reacts with two moles of NaOH. Therefore, the moles of NiCl₂ can be calculated as:

moles of NiCl₂ = (moles of NaOH) / 2

To find the moles of NaOH, we can use its molarity and volume:

moles of NaOH = (molarity of NaOH) x (volume of NaOH in liters)

Converting the volume of NaOH to liters:

volume of NaOH = 13.4 mL = 0.0134 L

Now we can calculate the moles of NaOH:

moles of NaOH = (0.280 M) x (0.0134 L) = 0.003752 mol

Substituting the moles of NaOH into the equation for moles of NiCl₂:

moles of NiCl₂ = (0.003752 mol) / 2 = 0.001876 mol

Next, we calculate the molarity of the NiCl₂ solution using the moles and volume:

Molarity of NiCl₂ = (moles of NiCl₂) / (volume of NiCl₂ in liters)

Converting the volume of NiCl₂ to liters:

volume of NiCl₂ = 30.0 mL = 0.0300 L

Now we can calculate the molarity of NiCl₂:

Molarity of NiCl₂ = (0.001876 mol) / (0.0300 L) ≈ 0.0625 M

Therefore, the molarity of the NiCl₂ solution is approximately 0.0625 M.

Learn more about molarity

brainly.com/question/8732513

#SPJ11

would prolyl hydroxylase be more likely to have a magnesium or a cobalt center?

Answers

The answer is that prolyl hydroxylase is more likely to have a cobalt center.

This is because prolyl hydroxylase is a member of the dioxygenase family of enzymes that require metal ions as cofactors. Cobalt is a commonly used metal ion for this family of enzymes, and it has been shown to enhance the activity of prolyl hydroxylase.

On the other hand, magnesium is not commonly used as a cofactor for dioxygenases. In 100 words, prolyl hydroxylase is more likely to have a cobalt center as it is a member of the dioxygenase family of enzymes, which require metal ions as cofactors.

Cobalt is a commonly used metal ion for this family of enzymes, including prolyl hydroxylase. The use of cobalt has been shown to enhance the activity of prolyl hydroxylase, whereas magnesium is not commonly used as a cofactor for dioxygenases. In conclusion, based on the available evidence, it is more likely that prolyl hydroxylase would have a cobalt center.

To know more about prolyl hydroxylase visit:

brainly.com/question/30901494

#SPJ11

Other Questions
when should a noncorporate taxpayer elect to forgo sec. 179 or elect out of bonus depreciation deductions in the current year? when the taxpayer has high marginal tax rates in the current year and expects to be in lower marginal rates in the future. when the taxpayer expects lower rates in the future. when the taxpayer has low marginal tax rates in the current year and expects to be in higher marginal rates in the future. when the taxpayer expects net operating losses in the future. brittany has been told you're pretty for a black girl which d of difference does this statement illustrate According to self-awareness theory, when will people change their behavior to match their standards? When self-discrepancies are highly accessible in memory. When people believe they can change their behavior. When people believe they cannot change their behavior. When people carefully monitor their behavior. AC is a straight line. Find the measure of the application of the top ten percent rule had its greatest effect on ______. What is the molarity of a glucose solution that contains 10.0 g of C6H12O6 (180.18 g/mol) dissolved in 100.0 mL of solution?0.00555 M0.0555 M0.555 M1.80 M18.0 M which forms of dance technologies permit a virtual dancer to fall apart, disintegrate, or be rendered in imaginative ways? now suppose neither consumption nor investment are affected by changes to the interest rate. show how will this affect the slope of the is curve and explain the economic intuition. with regard to amino acid skeleton scavenging, indicate whether the following amino acids are glucogenic, ketogenic, or both. lysine phenylalanine threonine alanine glycine leucine the stage of relationship development at which people move from being acquaintances to being close friends is____ enduring patterns of behavior and inner experience that deviate markedly from the expectations of the individual's culture are referred to as _______________. a nurse is preparing an in-service for a group of nurses about malpractice issues in nursing. which of the following examples should the nurse include in the teaching? a. leaving a nasogastric tube clamped after administering oral medication b. documenting communication with a provider in the progress notes of the client's medical records c. administering potassium via iv bolus d. placing a yellow bracelet on a client who is at risk for falls when retailers use the _________method, it is easiest to cut communication program expenses to try and generate additional sales. Consider a car at rest. We can conclude that the downward gravitational pull of the Earth on the car and the upward contact force of the Earth on it are equal and opposite because: A) The two forces form an interaction pair B) The net force on the car is zero C) Neither of the above? how do the net present value (npv) simplifying assumptions about the timing of cash flows differ from cash flow timing in the real world? select answer from the options below simplifying assumptions assume that all cash flows come at the end of the year, when in reality cash flows come throughout the year. simplifying assumptions assume that all cash flows come at the beginning of the year, when in reality all cash flows come at the end of the year. simplifying assumptions assume that cash flows come throughout the year, when in reality all cash flows come at the end of the year. simplifying assumptions assume that all cash flows come at the end of the year, when in reality all cash flows come at the beginning of the year. a die used in a certain board game has eight faces, of which 3 are red, 3 are yellow, and 2 are blue. each face is equally likely to land faceup when the die is tossed. in the game, a player tosses the die until blue lands faceup, and the number of tosses before blue lands faceup is counted. for example, a player who tosses the sequence shown in the following table has tossed the die 3 times before blue lands faceup. toss number 1 2 3 4 face color yellow yellow red blue what is the probability that a player will toss the die at least 2 times before blue lands faceup? which of the following is the least common emotional appeal for advertisers? is it possible to eject electrons from titanium metal using visible light? yes, it is possible. no, it is impossible. Read the following sentence.The little girl loved to wear sparkly hats that matchedWhich word belongs in the blank?OtheirO itsherhisdresses. which source is a secondary source?(1 point) responses a photograph a photograph a history book a history book a magazine article a magazine article a diary