What is the formula mass for magnesium fluoride?

Calculate E o , E, and ΔG for the following cell reactions (a) Mg(s) + Sn2+(aq) ⇌ Mg2+(aq) + Sn(s) where [Mg2+] = 0.025 M and [S

Rudik [331]

E⁰(cell) = 2.24V

E(cell) = 2.246V

∆G = -433 KJ/mol

Explanation:

Mg(s) + Sn²⁺(aq) ⇌ Mg²⁺(aq) + Sn(s)

[Mg2+] = 0.025 M

[Sn2+] = 0.040 M

First we need the standard reduction potentials:

. . . . . . . . . . . . . . . . . E°(V)

Mg²⁺ + 2 e⁻ ⇌ Mg(s). . .−2.372

Sn²⁺ + 2 e⁻ ⇌ Sn(s) . . . −0.13

Take the more negative (or less positive in other cases) one, and write it as an oxidation:

Mg(s) ⇌ Mg²⁺ + 2 e⁻. . .+2.372 V

Combine them,

Mg(s) + Sn²⁺ ⇌ Mg²⁺ + Sn(s)

E°(cell) = +2.372 – 0.13 V = 2.24 V

To get the cell potential under the conditions given, use the Nernst Equation:

E(cell) = E°(cell) – [(0.059)/n]•logQ = 2.24 V – 0.0295 V • log [Mg²⁺]/[Sn²⁺]

Note that the solids don't appear in Q, only the concs. of the dissolved ions.

E(cell) = 2.24 V – 0.0295 V X log (0.025)/(0.040)

= 2.24 + 0.006 V ≈ 2.246 V

The concentration ratio in Q (Sn²⁺ and Mg²⁺) is too close to 1 to shift E(cell) significantly from E°(cell) given the precision I have for the Sn reduction potential.

∆G = –nFE(cell) = –2(96.485 kJ/mol•V)(2.246 V) = –433 kJ/mol

E⁰(cell) = 2.24V

E(cell) = 2.246V

∆G = -433 KJ/mol

4 0

4 years ago

Arrange the following measurements, in seconds, from the greatest bias to the least bias. 6.63 ± 0.01 s, 6.6 ± 0.1 s, 6.52 ± 0.0

lord [1]

I understand here "bias" to be the uncertainty of measurements. So the order will be the following:

6.4 ± 0.5 s
6.6 ± 0.1 s,
6.63 ± 0.01 s,
6.52 ± 0.05 s,

(notice how the second number, the one behind the symbol ± gets smaller, as the bias gets smaller).

6 0

4 years ago

Periodic Table High School Reference Sheet

Ira Lisetskai [31]

I believe it should be B

8 0

3 years ago

NH3 (g) + HCl (g) + NH4Cl (s) What type of reaction does this equation represent?

kogti [31]

Answer:

Synthesis

Explanation:

Reaction Given:

NH₃+ HCI ------> NH₄Cl

Type of reaction = ?

Solution:

Look at the reactants and products of the reaction to know the type of reaction

NH₃+ HCI ------> NH₄Cl

In this reaction two reactant combine and give 1 products.

Reactant of the reaction

NH₃ = Ammonia

HCl = Hydrochloric acid

Product of the reaction

NH₄Cl = Ammonium chloride

So,

That ammonia (NH₃) react with Hydrochloric acid (HCl) and produces salt.

in this reaction NH₃ is a week base and take a proton from HCl and form ammonium ion and Cl ion. these two ions in combine form gives a salt called ammonium chloride.

Type of Reaction:

This is type of synthesis reaction, in which NH₃ and HCl combine and form a new compound that is ammonium chloride salt (NH₄Cl). As the synthesis reaction is that reaction in which two are more compounds or molecules combine and form a new compound.

6 0

3 years ago

Question 2(Multiple Choice Worth 3 points) What happens to the rate of most reactions as the reaction progresses? The rate remai

Sav [38]

Answer: -

The rate decreases as the concentration of the reactants decreases

Explanation: -

A reaction involves change of the reactants into products.

Initially there is only reactants. So the rate if reaction is high.

After some time there are products. So the amount of reactant is less.

Reactions involve collisions of reactant molecules. As the reactant amount decreases, collisions between the reactants decreases. As such the rate of reaction decreases with the progress of the reaction.

3 0

3 years ago