How is stoichiometry used to calculate energy released when a mass of liquid freezes?
A. Grams liquid x mol/g x delta Hreaction
B. Grams liquid x mol/g x delta Hfusion
C. Grams liquid x mol/g x delta Hvap
D. Grams liquid x mol/g x delta Hf​

Answer:

An unknown compound's 2,4-DNP product melting range is between 144-146'C. It does not give a silver mirror on the Tollens test and is slow to react to the chromic acid test. What would this compound be

Explanation:

From the given data it is clear that the unknown compound gives positive test with 2,4-DNP reagent.

That means it has a carbonyl group.Either aldehyde or ketone.

It does not give a silver mirror on the Tollens test and is slow to react to the chromic acid test.

That means aldehyde is absent.

So, the other carbonyl group that is ketone is present in the given unknown compound.

Answer:

i have no answer for part A

part B

the one that has a 4 can be divided by 2 because reducing

part c

you can determine if an equation is written in the correct way by balancing the equation as if it had not been done already.

Answer:

pH - 3.41 = acidic

pH = 10.25 = basic

pH = 7.00 = neutral

[H+] -3.5 x 10-5 = acidic

[H+] - 6.7 x 10-9 = basic

[OH-]-5.8 x 10-4 = basic

[H0] -1.0 x 10-7 = neutral

[OH-] - 4.5 x 10-13 = acidic

Explanation:

Let us note that from the pH scale, a pH of;

0 - 6.9 is acidic

7 is neutral

8 - 14 is basic

But pH= - log [H^+]

pOH = -log [OH^-]

Then;

pH + pOH = 14

Hence;

pH = 14 - pOH

For [H+] -3.5 x 10-5

pH = 4.46 hence it is acidic

For [H+] - 6.7 x 10-9

pH = 8.17 hence it is basic

[OH-]-5.8 x 10-4

pH= 10.76 hence it is basic

[H0] -1.0 x 10-7

pH = 7 hence it is neutral

[OH-] - 4.5 x 10-13

pH = 1.65 hence it is acidic

The majority of metals are found in ores.

But a few such as copper, gold, platinum, and silver frequently occur in the free state because they do not readily react with other elements.

Answer:

Assign priorities in the following set of substituents according to Cahn-Ingold-Prelog rules.

-OCH3 -Br -Cl -CH2OH

Explanation:

To give priorities for the substituents that are attached to chiral carbon and  to assign either R or S-configuration the following rules were proposed:

1. The atom with the highest atomic number is given first priority.

2. If the Groups attached to chiral carbon are having the same first atom, then check for the atomic number of the second atom.

Among the given groups,

-Br has the highest atomic number, so it is given first priority.

Then, -Cl.

Then, -OCH3

and the last one is -CH2OH.

Hence, the order is :

BCAD.

Answer:

a) NH₄NO₃ ⇒ N₂O + 2 H₂O

b) 1.69 × 10²³ molecules

Explanation:

Step 1: Write the balanced equation

NH₄NO₃ ⇒ N₂O + 2 H₂O

Step 2: Convert 11.2 g of NH₄NO₃ to moles

The molar mass of NH₄NO₃ is 80.04 g/mol.

11.2 g × 1 mol/80.04 g = 0.140 mol

Step 3: Calculate the moles of H₂O produced

0.140 mol NH₄NO₃ × 2 mol H₂O/1 mol NH₄NO₃ = 0.280 mol H₂O

Step 4: Calculate the number of molecules in 0.280 moles of water

We will use Avogadro's number.

0.280 mol × 6.02 × 10²³ molecules/1 mol = 1.69 × 10²³ molecules

Answer:

Explanation:

Answer is D 2,5-dimethylheptanal

You should accern the lowest possible number close to the parent name

Answer:

option a

hope helps you

have a great day

Answer:

[tex]Ba\ percentage\ in\ Mass=4.8\%[/tex]

Explanation:

From the question we are told that:

Mass of mixture [tex]m=3.455g[/tex]

Mass of Barium [tex]m_b=0.2815g[/tex]

Equation of Reaction is given as

[tex]Ba2+ + H2SO4 => BaSO4 + 2 H+[/tex]

Generally the equation for Moles of Barium  is mathematically given by

Since

 [tex]Moles of Ba^{2+} = Moles of BaSO_4[/tex]

Therefore

 [tex]Moles of Ba^{2+} = \frac{mass}{molar mass of BaSO4}[/tex]  

 [tex]Moles of Ba^{2+} = \frac{0.2815}{233.39}= 0.0012061 mol[/tex]

Generally the equation for Mass of Barium  is mathematically given by

 [tex]Mass\ of\ Ba^{2+} = Moles * Molar mass of Ba^{2+}[/tex]  

 [tex]Mass\ of\ Ba^{2+} = 0.0012061 * 137.33 = 0.1656 g[/tex]

Therefore

 [tex]Ba\ percentage\ in\ Mass = mass of Ba^{2+}/mass of sample * 100%[/tex]    

 [tex]Ba\ percentage\ in\ Mass= \frac{0.1656}{ 3.455 }* 100%[/tex]

 [tex]Ba\ percentage\ in\ Mass=4.8\%[/tex]

Answer:

Theoretical yield is 138.4 g

Explanation:

In the first step we determine the reaction:

3Mg + N₂ → Mg₃N₂

Mass of reactant is 100 g. We assume the nitrogen is in excess, so we work with Mg. We convert mass to moles:

100 g . 1mol/ 24.3g = 4.11 moles of Mg.

Ratio is 3:1. 3 moles of Mg can produce 1 mol of nitride

Our 4.11 moles, may produce (4.11 . 1)/3 = 1.37 moles of Mg₃N₂

We convert mass to moles, to find the theoretical yield:

1.37 mol . 100.9 g/mol = 138.2 g

Answer:

True.

Explanation:

The information presented in the question above regarding linoleic acid is true. Linoleic acid is, in fact, found in many oils and fats in the ester form. In addition, linoleic acid is considered a polyunsaturated fatty acid, due to the presence of two unsaturations in its composition. Its chemical formula is CH3-(CH2)4-CH=CH-CH2-CH=CH-(CH2)7COOH and it is an essential fatty acid for the human body, as it is essential in the composition of arachidonic acid that is responsible for building muscle, managing body fat thermogenesis, and regulating core protein synthesis.

Answer:

Please find the complete question and its solution file in the attachment.

Explanation:

The equation for the energy required to melt 2 kg of gold is 3440 kJ.

Energy is the ability to do work or cause change. It is an essential part of everyday life and is present in many forms, such as thermal energy, electrical energy, chemical energy, and mechanical energy. Energy can be converted from one form to another in order to do work.

The equation for calculating the energy required to melt a certain mass of material is Q = m x Lf, where Q is the energy required (in joules), m is the mass of the material (in kilograms), and Lf is the latent heat of fusion (in joules per kilogram).
Using the table below, we can see that the latent heat of fusion for gold is 1760 kJ/kg. Therefore, the equation for the energy required to melt 2 kg of gold is: Q = 2 kg x 1760 kJ/kg = 3440 kJ.

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Answer:

co+ o2+ 2co2 is not balanced reaction

Answer:

The molar concentration of the H₂SO₄ solution is 0.28 M

Explanation:

Molar concentration = number of moles / volume in litres

Number of moles = molar concentration × volume

From the equation of reaction, molar ratio of acid to base = 1 : 2

Using the formula; Na/Nb = CaVa/CbVb

Where Na is the number of moles of acid; Nb = number of moles of base; Ca = concentration of acid; Va = volume of acid; Cb = concentration of base; Vb = volume of base; Na/Nb = mole ratio of acid to base

Substituting the given values in the equation:

1/2 = Ca × 25.18 / 0.93 × 14.92

Ca = 0.93 × 14.92/ 25.18 × 2

Ca = 0.28M

Therefore, the molar concentration of the H₂SO₄ solution is 0.28 M

Answer:

Please find the complete solution in attached file.

Explanation:

Periodic law is the the properties of the elements that repeat in a regular way as the atomic numbers increase.

Periodic chart organized collection of all chemical elements arranged roughly according to increasing atomic weight. The periodic recurrence of several features in the elements was originally identified by Dmitry I. Mendeleyev in 1869.

1. This is a vertical arrangement of elements in the periodic table   group

2. This is a horizontal arrangement of elements in the periodic table   period

3. The properties of the elements repeat in a regular way as the atomic numbers increase periodic law

4. Element 19 begins this arrangement in the periodic table period

5. The chemical properties of elements 12, 20, and 38 demonstrate this principle.  periodic law

Therefore, periodic law is the the properties of the elements that repeat in a regular way as the atomic numbers increase.

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Answer:

1.20x10⁻²⁰μL

Explanation:

1cm³ is equal to 1milliliter. As we must know, 1milliliter = 1000 microliters, 1000μL. To convert the 1.20x10⁻²³mL we need to use the conversion factor: 1mL = 1000μL.

The volume of tantalum in μL is:

1.20x10⁻²³mL * (1000μL /1L) = 1.20x10⁻²⁰μL

Answer:

14 moles of oxygen needed to produce 12 moles of H2O.

Explanation:

We are given that balance eqaution

[tex]2C_2H_6+7O_2\rightarrow 4CO_2+6H_2O[/tex]

We have to find number of moles of O2 needed  to produce 12 moles of H2O.

From given equation

We can see that

6 moles of   H2O produced by Oxygen =7 moles

1 mole of   H2O produced by Oxygen=[tex]\frac{7}{6}[/tex]moles

12 moles of H2O produced by Oxygen=[tex]\frac{7}{6}\times 12[/tex]moles

12 moles of H2O produced by Oxygen=[tex]7\times 2[/tex]moles

12 moles of H2O produced by Oxygen=14 moles

Hence, 14 moles of oxygen needed to produce 12 moles of H2O.

The amount of oxygen required for the combustion of ethane to produce 12 moles of water is 14 moles.

The moles of oxygen produced in the reaction can be given from the stoichiometric law of the balanced chemical equation.

The balanced chemical equation for the combustion of ethane is:

[tex]\rm 2\;C_2H_6\;+\;7\;O_2\;\rightarrow\;4\;CO_2\;+\;6\;H_2O[/tex]

The 6 moles of water are produced from 7 moles of oxygen. The moles of oxygen required to produce 12 moles of water are:

[tex]\rm 6\;mol\;H_2O=7\;mol\;Oxygen\\12\;mol\;H_2O=\dfrac{7}{6}\;\times\;12\;mol\;O_2\\ 12\;mol\;H_2O=14\;mol\;O_2[/tex]

The moles of oxygen required to produce 12 moles of water are 14 moles.

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Answer:

unsaturated fats, which are liquid at room temperature,are different from saturated fat because they contain one or more double bonds and fewer hydrogen atoms on their carbon chain.

Answer:

hydrogen bonds

Explanation:

similarly CH3OH also has a OH group and H hydrogen thus it will also form h-bonding.

Answer:

amount, pH value.

Explanation:

The buffer range is the pH range in which the buffer performs optimally, i.e., neutralizes even when a strong acid or base is introduced to it and resists any major change in its pH value.

The buffer capacity is the amount of acid or base that can be added before the pH of the buffer solution changes significantly.

Thus, the final statement becomes,

Buffer capacity is the amount of acid or base a buffer can handle before pushing the pH value outside of the buffer range.

Answer:

Amount

pH value

Buffer capacity is the amount  of acid or base a buffer can handle before pushing the pH  outside of the buffer range.

A buffer however consists of a weak acid and its conjugate base.Its major advantage is the ability to resist changes in pH when an acid or a base is added to the solution.

The human blood is also an example of a buffer solution as it is able to resist changes in pH when we eat or drink certain types of food.

An example of a buffer include acetic acid (HC₂H₃O₂) which is a weak acid and sodium acetate (NaC₂H₃O₂) which is a salt derived from that acid).

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Answer:

SF2(aq) → S²⁺(aq) + 2F-(aq)

Explanation:

The sulfur difluoride, SF2, dissolves in water because the differences in electronegativities are considerable (3.98 for Fluorine and 2.58 for S) doing the F-S bond polar. As water is a polar solvent will dissolve the SF2 as follows:

As Fluorine has a > electronegativity than S, the Fluorine will be negative and S will be positive. Also, all halogen ions has a charge of -1.

Answer: The moles of gas present in the cylinder is 0.34 moles.

Explanation:

Given: [tex]P_{1}[/tex] = 2.7 atm,   [tex]V_{1}[/tex] = 3.1 L,     [tex]T_{1}[/tex] = 300 K

[tex]P_{2}[/tex] = ?,      [tex]V_{2}[/tex] = 9.4 L,       [tex]T_{2}[/tex] = 610 K

Formula used to calculate the final temperature is as follows.

[tex]\frac{P_{1}V_{1}}{T_{1}} = \frac{P_{2}V_{2}}{T_{2}}[/tex]

Substitute the values into above formula as follows.

[tex]\frac{P_{1}V_{1}}{T_{1}} = \frac{P_{2}V_{2}}{T_{2}}\\\frac{2.7 atm \times 3.1 L}{300 K} = \frac{P_{2} \times 9.4 L}{610 K}\\P_{2} = \frac{5105.7}{2820} atm\\= 1.81 atm[/tex]

Now, moles present upon heating the cylinder are as follows.

[tex]P_{2}V_{2} = n_{2}RT_{2}\\1.81 atm \times 9.4 L = n_{2} \times 0.0821 L atm/mol K \times 610 K\\n_{2} = \frac{17.014}{50.081} mol\\= 0.34 mol[/tex]

Thus, we can conclude that moles of gas present in the cylinder is 0.34 moles.

Answer:

Explanation:

Using the formula below to calculate the heat absorbed in each trial:

Q = m × c × ∆T

Where;

Q = amount of heat absorbed (J)

m = mass of substance (g)

c = specific heat of water (4.184J/g°C)

∆T = change in temperature (°C)

Trial 1: Heat 30.0 grams of water at 0 °C to a final temperature of 40.0 °C.

Q = 30 × 4.184 × (40 - 0)

Q = 30 × 4.184 × 40

Q = 5,020.8J

Trial 2: Heat 40.0 grams of water at 10.0 °C to a final temperature of 40.0 °C.

Answer:

The same amount of heat is absorbed in both the experiments because the product of mass, specific heat capacity, and change in temperature are equal for both.

Explanation:

Explanation:

Using the formula below to calculate the heat absorbed in each trial:

Q = m × c × ∆T

Trial 1: Heat 30.0 grams of water at 0 °C to a final temperature of 40.0 °C.

Q = 30 × 4.184 × (40 - 0)

Q = 30 × 4.184 × 40

Q = 5,020.8J

Trial 2: Heat 40.0 grams of water at 10.0 °C to a final temperature of 40.0 °C.

Q=40*4.184*30

Q=5020.8J

Answer:

In the case of mixtures of ethanol and water, this minimum occurs with 95.6% by mass of ethanol in the mixture. The boiling point of this mixture is 78.2°C, compared with the boiling point of pure ethanol at 78.5°C, and water at 100°C. You might think that this 0.3°C doesn't matter much, but it has huge implications for the separation of ethanol / water mixtures. The next diagram shows the boiling point / composition curve for ethanol / water mixtures. I've also included on the same diagram a vapor composition curve in exactly the same way as we looked at on the previous pages about phase diagrams for ideal mixtures.