Final Chem 2 Review! (Electrochemistry)

AHHH

100

What does oxidation refer to? 

The loss of electrons

200

What is the oxidation state of Sulfur in the following compounds?

a) H₂S_(aq)

b) S_8(s)

c) SO₄^-2_(aq)

a) -2

b) 0

c) +6

300

How many moles of K₂Cr₂O₇ are needed to react with one mole of H₂S in the following reaction?

K₂Cr₂O₇ + 4H₂SO₄ + 3H₂S → K₂SO₄ + Cr₂(SO₄)₃ + 7H₂O + 3S

1/3

Look at the ratio!

400

What's the best part about dead batteries?

They're free of charge!

500

Balance the following redox reaction in a basic solution.

CN^-_(aq) + MnO₄^-_(aq) => CNO^-_(aq) + MnO_2(s)

3CN^-_(aq) + H₂O_(l) + 2MnO₄^-_(aq) => 3CNO^-_(aq) + 2MnO_2(s) + 2OH^-_(aq)

FINALS

100

What is the oxidation state of chlorine in MgCl₂?

-2

200

Complete the following statement from the choices given:

Electrons "move" spontaneously from _____________.

a) low potential energy to high potential energy

b) high potential energy to low potential energy

c) low kinetic energy to high kintetic energy

d) high kinetic energy to low kinetic energy

B

300

In the following reaction, which compound is the reducing agent? The oxidizing agent?

I_2(s) + OCl^-_(aq) => IO₃^-_(aq) + Cl^-_(aq)

Oxidizing Agent: OCl^-

Reducing Agent: I₂

400

Balance the following reaction in an acidic solution.

MnO₄^2-_(aq) => MnO₄^-_(aq) + MnO_2(s)

4H⁺_(aq) + 3MnO₄^2-_(aq) => 2MnO₄^-_(aq) + MnO_2(s) + 2H₂O_(l)

500

Use the following information to answer the questions below.

Reaction:  Fe₂⁺_(aq) + 2Ag_(s) => Fe_(s) + 2Ag⁺_(aq)

(E^o) Values:

Fe₂⁺_(aq) + 2e^- => Fe_(s)    (E^o) = -0.44

Ag⁺_(aq) + e^- => Ag_(s)         (E^o) = +0.80

a) Which component is the strongest oxidizing agent?

b) Evaluate (E^o) for the reaction.

c) Is the reaction spontaneous under standard conditions?

a) Ag⁺_(aq)

b) -1.24 V

c) No, because E^o < 0!

OH NO

100

What is the acronym/saying that we have used for understanding oxidation versus reduction in terms of electrons?

OIL RIG

200

What is one real-life example of oxidation occurring?

Iron rusting

300

For the reaction below, E^o = -1.69 V. Which one of the four components is the strongest oxidizing agent? (Most reactive and gets reduced!)

2Co²⁺_(aq) + Sn⁴⁺_(aq) => 2Co³⁺_(aq) + Sn²⁺(aq) 

Co³⁺_(aq)

400

I have nothing to put here because I've run out of ideas

Congrats

500

Given the following information, which one of the following 4 species is the strongest reducing agent?

Ni₂⁺_(aq) + 2e^- => Ni_(s)    E^o_red = -0.25 V

Sn₄⁺_(aq) + 2e^- => Sn₂⁺_(aq)    E^o_red = +0.13 V

Now, is the following reaction spontaneous or nonspontaneous if all reactants and products are in their standard states?

Ni₂⁺_(aq) + Sn₂⁺_(aq) => Ni_(s) + Sn₄⁺_(aq)

Strongest Reducing Agent: Ni_(s)

Reaction: Nonspontaneous

Oh Wait

100

In a galvanic cell, what is the reduction side identified as? The oxidation side?

Reduction: Cathode

Oxidation: Anode

200

What are the oxidation states of iodine for the reaction below (both reactant and product)?

I_2(s) + OCl^-_(aq) => IO₃^-_(aq) + Cl^-_(aq)

Reactant: 0

Product: +5

300

Take a break! You're doing great :)

Bwahaha Chemistry

400

Balance the following basic condition reaction:

Br¯ + MnO₄¯ ---> MnO₂ + BrO₃¯

H₂O + 2MnO₄¯ + Br¯ ---> 2MnO₂ + BrO₃¯ + 2OH¯

500

Use the given information to answer the question below.

Reaction: 2NO_2(g) => N₂O_4(g)

H^o = -57.9 kJ (Exothermic)

S^o =  -176.7 J/K = -0.1767 kJ/K

1) Estimate G^o and K_p at 100K and 500K.

100K: 

G^o = -40.2 kJ

K_p = 9.98 x 10²⁰

500K:

G^o = +30.5 kJ

K_p = 6.51 x 10^-4

 

Review!

100

The type of reaction in which oxidation and reduction co-occur is called what?

Redox Reaction

200

In the following reaction, which species is being reduced? Oxidized?

3Hg²⁺ + Fe_(s) → 3Hg₂ + 2Fe³⁺

Reduced: Hg

Oxidized: Fe

300

Balance the following redox reaction (no acidic or basic solutions).

Co³⁺_(aq) + Sn²⁺_(aq) => Co²⁺_(aq) + Sn⁴⁺_(aq)

 2Co³⁺_(aq) + Sn²⁺_(aq) => 2Co²⁺_(aq) + Sn⁴⁺_(aq)

400

A 50 mL 0.500M weak base NH₃ (K_b = 1.80 x 10^-5) solution was titrated with 1.00M HCl.

a) What is the pH when 0.00 mL HCl is added?

b) What is the pH when 10.00 mL HCl is added?

c) What is the pH when 12.50 mL HCl is added?

d) What is the pH when 20.00 mL HCl is added?

e) What is the pH when 25.00 mL HCl is added?

f) What is the pH when 50.00 mL HCl is added?

a) 11.477

b) 9.43

c) 1/2 equivalent point: 9.255

d) is a buffer region

e) equivalent point: 4.6275

500

Use the given information to answer the question below.

Reaction: 2NO_2(g) => N₂O_4(g)

H^o = -57.9 kJ (Exothermic)

S^o =  -176.7 J/K = -0.1767 kJ/K

2) At 500K, if p(NO₂ ) = 0.2 atm and p(N₂O₄) = 0.05 atm, calculate delta G. What process, if any, occurs?

deltaG = +31.4 kJ

Spontaneous Reaction!