What is the mass number of an element

Answer:

[tex]SF_4[/tex]

Explanation:

The first thing would be to calculate the number of moles of each element in the compound.

No of moles of sulfur (S) = mass/molar mass

                                        = 29.68/32.065 = 0.9256

No of moles of fluorine (F) = mass/molar mass

                                       = 70.32/18.998 = 3.7014

Then, let us find the atomic ratio of each of the element in the compound by dividing by the no of moles by the smallest no of mole:

            S            :             F

      [tex]\frac{0.9256}{0.9256}[/tex] = 1       :       [tex]\frac{3.7014}{0.9256}[/tex] = 4

Therefore, the empirical formula for the compound is [tex]SF_4[/tex]

Answer:

the acid strength is the order of [tex]\mathsf{HF _{(aq)} }[/tex] > [tex]\mathsf{C_6H_5COOH _{(aq)} }[/tex] > [tex]\mathsf{C_6H_5OH _{(aq)} }[/tex]

Explanation:

Given that :

a . [tex]\mathsf{C_6H_5COO^- _{(aq)} + C_6H_5OH _{(aq)} \to C_6H_5COOH _{(aq)} + C_6H_5O^- _{(aq)}}[/tex]

b.  [tex]\mathsf{ F^- _{(aq)} + C_6H_5OH _{(aq)} \to C_6H_5O^- _{(aq)} + HF _{(aq)} }[/tex]

c.  [tex]\mathsf{C_6H_5COOH _{(aq)} + F^- _{(aq)} \to HF _{(aq)} + C_6H_5COO^- _{(aq)} }[/tex]

Acid strength is the ability of an acid  to dissociate into a proton and an anion. Take for instance.

HA  ↔ H⁺ + A⁻

The  acid strength of the following compounds above are:

[tex]\mathsf{C_6H_5OH _{(aq)} }[/tex] = 1.00 × 10⁻¹⁰

[tex]\mathsf{HF _{(aq)} }[/tex] = 6.6 × 10⁻⁴

[tex]\mathsf{C_6H_5COOH _{(aq)} }[/tex] = 6.3 × 10⁻⁵

As the acid dissociation constant increases the relative acid strength also increases.

From above, the acid strength is the order of [tex]\mathsf{HF _{(aq)} }[/tex] > [tex]\mathsf{C_6H_5COOH _{(aq)} }[/tex] > [tex]\mathsf{C_6H_5OH _{(aq)} }[/tex]

[tex]\mathsf{C_6H_5COO^- }[/tex], [tex]\mathsf{C_6H_5O^- _{(aq)}}[/tex] and F⁻ are Bronsted- Lowry acid

Bronsted- Lowry acid are molecule or ion that have the ability to donate a proton.

Answer:

A. Rank the following substances in order of decreasing standard molar entropy (S∘).

Rank the gases from largest to smallest standard molar entropy

I2(g)>Br2(g)>Cl2(g)>F2(g)

B. Rank the gases from largest to smallest standard molar entropy. To rank items as equivalent, overlap them.

H2O2(g)>H2S(g) >H2O(g)

C. Rank the gases from largest to smallest standard molar entropy. To rank items as equivalent, overlap them.

C(s, amorphous) >C(s, graphite)>C(s, diamond)

Explanation:

Hello,

In this case, we can apply the following principles to explain the order:

- The greater the molar mass, the larger the standard molar entropy.

- The greater the molar mass and the structural complexity, the larger the standard molar entropy.

- The greater the structural complexity, the larger the standard molar entropy.

A. Rank the following substances in order of decreasing standard molar entropy (S∘).

Rank the gases from largest to smallest standard molar entropy

I2(g)>Br2(g)>Cl2(g)>F2(g)

This is due to the fact that the greater the molar mass, the larger the standard molar entropy.

B. Rank the gases from largest to smallest standard molar entropy. To rank items as equivalent, overlap them.

H2O2(g)>H2S(g) >H2O(g)

This is due to the fact that the greater the molar mass and the structural complexity, the larger the standard molar entropy as the hydrogen peroxide has four bonds and weights 34 g/mol as well as hydrogen sulfide that has two bonds only.

C. Rank the gases from largest to smallest standard molar entropy. To rank items as equivalent, overlap them.

C(s, amorphous) >C(s, graphite)>C(s, diamond)

Since the molecular complexity is greater in the amorphous carbon (messy arrangement), mid in the graphite and lower in the diamond (well organized).

Regards.

Answer:

The coefficients are; 4, 0, 2, 2

Explanation:

The equation is given as;

HCl + O2 --> H2O + Cl2

Upon balancing the equation, we have;

4HCl + O2 --> 2H2O + 2Cl2

Answer:

The answer is D) Electrolytic cell

Explanation:

An electrolytic cell is a device used for the decomposition by the electrical current of ionized substances called electrolytes.

When the two electrodes are connected by a wire, electrical energy is produced, and a flow of electrons takes place from the electrode.

These cells are the closest thing to a galvanic battery.

Answer:

b. voltaic cell

Explanation:

Founders Education answer. had to take this quiz 4 times

Answer:

73.1707317073%

=> Approximately 73.2%

Explanation:

Total = 60 + 10 + 12

=> 82

Test tubes are 60/82

=> 30/41

=> 73.1707317073%

=> Approximately 73.2%

Answer:

73.17%

Explanation:

To find the percentage of test tubes to the overall glassware, we need to get the number of test tubes divided by the total number of glassware.

12 beakers + 10 flasks + 60 test tubes = 82 glassware

% test tube = 60 / 82 = .7317 ==> 73.17 %

So 73.17 % of the glassware was test tubes.

Cheers.

Answer:

PLEASE SHOW ME THE ELEMENTS OR I WOULD ENLIST ALL THE ELEMENTS.

Explanation:

Group 6A (or VIA) of the periodic table are the chalcogens: the nonmetals oxygen (O), sulfur (S), and selenium (Se), the metalloid tellurium (Te), and the metal polonium (Po)

Answer:

Al(s)<NaF(s)<HF(g)<SiH4(g)<SiF4(g)

Explanation:

Hello,

In this case, we can arrange the increasing order of entropy at 25 \°C by taking into account, at first, that since solids are more molecularly organized than gases, the first we have solid sodium fluoride and solid aluminium, but in this case, as the higher the molar mass, the higher the entropy, the molar mass of aluminium is 27 g/mol and 42 g/mol for sodium fluoride, therefore, we first have:

Al(s)<NaF(s)

Afterwards, since the molar mass of hydrogen fluoride (HF), silicon fluoride (SiF4) and silane (SiH4) are 20, 104 and 32 g/mol respctively, since silicon fluoride has the greater molar mass, it also has the higher entropy. In such a way, the overall order turns out:

Al(s)<NaF(s)<HF(g)<SiH4(g)<SiF4(g)

Best regards.

Answer:

See explanation

Explanation:

So, I'm gonna take a shot at this one and say this:

With a strongly acidic/basic solution, you'll get a high conductivity when preforming a conductivity test.

The more acidic or basic a substance is, the higher the electrical conductivity.

Based on how high or low the conductivity is, it will give you an idea of the substance's pH.

Hope that made since or gave you an idea of what you're looking for. Good luck :)

Answer:

The correct answer is 1332 KJ.

Explanation:

Based on the given information,  

ΔH°f of C2H4 is 51.9 KJ/mol, ΔH°O2 is 0.0 KJ/mol, ΔH°f of CO2 is -394 KJ/mol, and ΔH°f of H2O is -286 KJ/mol.  

Now the balanced equation is:  

C2H4 (g) + 3O2 (g) ⇔ 2CO2 (g) + 2H2O (l)

ΔH°rxn = 2 × ΔH°f CO2 + 2 × ΔH°fH2O - 1 × ΔH°fC2H4 - 3×ΔH°fO2

ΔH°rxn = 2 (-394) + 2(-286) - 1(51.9) - 3(0)

ΔH°rxn = -1411.9 KJ

Now, the given ΔS°f of C2H4 is 219.8 J/mol.K, ΔS°f of O2 is 205 J/mol.K, ΔS°f of CO2 is 213.6 J/mol.K, and ΔS°f of H2O is 69.96 J/mol.K.  

Now based on the balanced chemical reaction,  

ΔS°rxn = 2 × ΔS°fCO2 + 2 ΔS°fH2O - 1 × ΔS°f C2H4 - 3 ΔS°fO2

ΔS°rxn = 2 (213.6) + 2(69.96) - 1(219.8) -3(205)

ΔS°rxn = -267.68 J/K or -0.26768 KJ/K

T = 25 °C or 298 K

Now putting the values of ΔH, ΔS and T in the equation ΔG = ΔH-TΔS, we get

ΔG = -1411.9 - 298.0 × (-0.2677)

ΔG = -1332 KJ.  

Thus, the maximum work, which can obtained is 1332 kJ.  

Answer:

quartz

Explanation:

The correct option would be quartz.

Allotropy is a phenomenon that describes the natural existence of the same element in different forms with different physical characteristics. Allotropes are therefore different forms of the same element.

Carbon as an element has several allotropes which include diamond, graphite, graphene, amorphous carbon, and fullerenes. Quartz is a crystalline solid that is composed of silicon dioxide and not carbon.

Hence, all the options are carbon allotropes except quartz.

Answer:

Mass = 11.688g

Explanation:

Volume = 2.00L

Molar concentration = 0.100M

Mass = ?

These quantities are relatted by the following equation;

Conc = Number of moles / volume

Number of moles = Conc * Volume = 2 * 0.100 = 0.2 mol

Number of moles = Mass / Molar mass

Mass = Number of moles * Molar mass

Mass = 0.2mol * 58.44g/mol

Mass = 11.688g

Answer:

Explanation:

Sr(OH)2 (aq) ⇔ Sr+2 (aq) + 2OH- (aq)

Answer:

-195.8º < -191.5º < 100º

Explanation:

Water, or H20, starts boiling at 100ºC.

Nitrogen, or N2, starts boiling at -195.8ºC.

Carbon monoxide, or C0, starts boiling at -191.5ºC.

When we place these in order from decreasing boiling point:

-195.8º goes first, then -191.5º, and 100º goes last.

Answer:

therefore, N2, CO, H20

Decreasing boiling point

Explanation:

the bond existing in H2O is hydrogen bond

bond existing in N2 is covalent bond, force existing is dipole-dipole-interaction

bond existing in CO is covalent bond , force existing between is induced -dipole- induced dipole-interaction

hydrogen bond is the strongest , followed by dipole-dipole-interaction and induced -dipole- induced dipole-interaction

the stronger the bond , the higher the boiling point

therefore, N2, CO, H20

-------------------------------------->

Decreasing boiling point

Answer:Cobb

Explanation:What y'all

Answer:

a. NCl3

Explanation:

All the elements stated are non metals. Generally the bond between non metals is a covalent bond. However depending on how the electrons are shared, this bond can either be polar or non polar.

A non polar covalent bond is formed when the electrons are shared equally between the atoms.

A way to determine if a bond is non polar or polar covalent is by comparing the electronegativity values.

If the electronegativity difference is less than 0.5, it is regarded as a non polar covalent bond.

Going back to the question;

Between N and Cl; the electronegativity difference is 3.0 - 3.0 = 0

Between Cl and O; the electronegativity difference is 3.5 - 3.0 = 0.5

Between Cl and P; the electronegativity difference is 3.5 - 2.1 = 1.4

From these we can tell that the correct option is option A.

Answer:

A precipitate will form, AgI

Explanation:

When Ag⁺ and I⁻ ions are in an aqueous media, AgI(s), a precipitate, is produced or not based on its Ksp expression:

Ksp = 8.3x10⁻¹⁷ = [Ag⁺] [I⁻]

Where the concentrations of the ions are the concentrations in equilibrium

For actual concentrations of a solution, you can define Q, reaction quotient, as:

Q = [Ag⁺] [I⁻]

If Q > Ksp, the ions will react producing BaCO₃, if not, no precipitate will form.

Actual concentrations of Ag⁺ and I⁻ are:

[Ag⁺] = [AgNO₃] = 2.0x10⁻⁵ × (300mL / 500.0mL) = 1.2x10⁻⁵M

[I⁻] = [NaI] = 2.5x10⁻⁹ × (200mL / 500.0mL) = 1.0x10⁻⁹M

500.0mL is the volume of the mixture of the solutions

Replacing in Q expression:

Q = [Ag⁺] [I⁻]

Q = [1.2x10⁻⁵M] [1.0x10⁻⁹M]

Q = 1.2x10⁻¹⁴

As Q > Ksp

Answer:

The correct answer is : option D. The test was inconclusive because he forgot to add heat.

Explanation:

Benedict's test is a test that is used to confirm the presence of the simple carbohydrates (mono saccharides and some disaccharides). It is a reagent made by mixture of solution of CuSO4 with sodium citrate and Na2CO3.

Benedict's reagent is added to the substance to test and then heated if it turns yellow to orange or red the presence of simple sugar is confirmed.

Thus, the correct answer is : option D. The test was inconclusive because he forgot to add heat.

Answer:

The test was inconclusive because the student forgot to add heat.

Explanation:

If the test revealed it was not glucose, then the student could run these tests. The student, however, does not need these substances to run the glucose test properly.

Answer:

there are 37,8541 liters in 10 gallons

Explanation:

The answer is directly proportional, because when there is more concentration their will more reactants to react fast diring the chemical reaction which increases the rate of chemical reaction.

So, we can state that the relationship between them are directly proportional.

Hope it helps...

Answer:

A

Explanation:

Absorbing moisture to protect goods from damage. Hence, option A is correct.

Silica gel is a desiccant, or drying agent, that manufacturers often place in little packets to keep moisture from damaging certain food and commercial products.

Silica Gel is a good drying agent for preventing corrosion, contamination, spoilage, and mould growth in many commodities and products due to its physical properties.

Learn more about silica gel here:

https://brainly.com/question/18723447

#SPJ2

Answer:

804 J

Explanation:

Step 1: Given data

Step 2: Calculate the energy required (Q)

We will use the following expression.

Q = c × m × ΔT

Q = 0.0235J·g⁻¹K⁻¹ × (1.50 × 10³g) × [15.0°C-(-7.8°C)]

Q = 804 J

Answer:

After 47.9 days, will remain 14.5mg of the isotope

Explanation:

The radioactive decay follows always first-order kinetics where its general law is:  

Ln[A] = -Kt + ln[A]₀

Where [A] is actual concentration of the atom, k is rate constant, t is time and [A]₀ is initial concentration.

We can find rate constant from half-life as follows:

[tex]t_{1/2} = \frac{ln2}{K}[/tex]

K = ln 2 / 27.7 days

K = 0.025 days⁻¹

Replacing, initial amount of isotope is 48.0mg = [A]₀ , K is 0.025 days⁻¹ and t = 47.9 days:

Ln[A] = -Kt + ln[A]₀

Ln[A] = -0.025 days⁻¹*47.9 days + ln (48.0mg)

ln [A] = 2.6726

[A] = e^ (2.6726)

[A] = 14.5mg

Answer:

b

Explanation:

Provided the experiment is about the transfer of heat from one medium to another, any residual hot water on the metal would have added to the heat transferred from the metal to the cold water system.

The residual hot water on the metal posses its own heat and when such is transferred along with the metal into the cold water, the heat from the residual hot water will interfere with the measurement of the actual heat transferred to the cold water by the metal. Hence, the accuracy of the result would be impacted.

The correct option is b.

Answer:

The correct answer is - 1.02 V

Explanation:

From the reduction-oxidation reaction:

Ni²⁺(aq) + 2 Fe²⁺(aq) → Ni(s) + 2 Fe³⁺(aq)

Ni²⁺ is reduced to Ni(s) while Fe²⁺ is oxidized to Fe³⁺. Thus, the half reactions are:

Reduction (cathode) : Ni²⁺(aq) + 2 e‑ → Ni(s)                    Eº= ‑0.25 V

Oxidation (anode) :  2 x (Fe²⁺ → Fe³⁺ + e-)(aq)                Eº= -0.77 V

                                -------------------------------------

                     Ni²⁺(aq) + 2 Fe²⁺(aq) → Ni(s) + 2 Fe³⁺(aq)

In order to calculate the Eºcell, we have to add the reduction potential of the reaction in cathode (reduction) to the oxidation potential of the anode (oxidation):

Eºcell= Eºr + Eºo= (-0.25 V) + (-0.77 V) = - 1.02 V

Answer:

Yes

Explanation:

The balanced equation of the reaction is;

FeBr2 (aq) + Cl2 (g) → FeCl2 (aq) + Br2 (aq)

This reaction is possible because chlorine is more electronegative than bromine and can displace it from its salt.

In group seventeen, electro negativity decreases down the group. Hence as we move down the group, elements become less electronegative and can be displaced from their salt by more electronegative elements found earlier in the group.

Hence chlorine can displace bromine in FeBr2 to form FeCl2.

Answer:

Yes, because Cl2 has higher activity than Br2

Explanation:

Answer:

Electrical current drives nonspontaneous reactions in electrolytic cells.

Explanation:

Electrochemical cells are cells that produce electrical energy from chemical energy.

There are two types of electrochemical cells; voltaic cells and electrolytic cells.

A voltaic cell is an electrochemical cell in which electrical energy is produced from spontaneous chemical process while an electrolytic cell is an electrochemical cell where electrical energy is produced from nonspontaneous chemical processes. Current is needed to drive these nonspontaneous chemical processes in an electrolytic cell.

Answer:

electrolytic cells generate electricity through a non-spontaneous reaction while voltaic cells absorb electricity to drive a spontaneous reaction.

Explanation:

Answer via Educere/ Founder's Education

Answer:

a. [tex]3CH_4+2H_2O+CO_2\rightarrow 4CH_3OH[/tex]

b. [tex]2N_2O_5\rightarrow 2N_2 + 5O_2[/tex]

c. [tex]2H_2+2CO_2+O_2\rightarrow 2H_2CO_3[/tex]

Explanation:

Hello,

In this case, since those rate relationships have the stoichiometric coefficient at the denominators of the fractions preceding each ratio and the negative terms account for reactants and positive for products, we have:

a. [tex]3CH_4+2H_2O+CO_2\rightarrow 4CH_3OH[/tex]

b. [tex]2N_2O_5\rightarrow 2N_2 + 5O_2[/tex]

c. [tex]2H_2+2CO_2+O_2\rightarrow 2H_2CO_3[/tex]

Best regards.

Answer:

Silver.

Explanation:

Hello,

In this case, for the redox reaction:

[tex]Ni^0(s)+Ag^+(aq)\rightarrow Ni^{2+}+Ag^0(s)[/tex]

We can see the nickel is being oxidized as its oxidation state increases from 0 to 2+ whereas the oxidation state of silver decreases from +1 to 0, it means that the oxidizing agent is silver and the reducing agent is nickel.

Best regards.

The oxidizing agent in the redox reaction represented by the following cell notation is Silver.

The redox reaction is

Ni(s) | Ni2+(aq) || Ag+(aq) | Ag(s)

here the nickel is being oxidized since its oxidation state rises from 0 to 2+ while on the other hand,  the oxidation state of silver is reduced from +1 to 0, it means that the oxidizing agent is silver and the reducing agent is nickel.

Learn more about reaction here: https://brainly.com/question/4241156