Ch 18 Electrochem review

Front

What is an oxidizing agent?

Back

An oxidizing agent is a substance that gains electrons in a chemical reaction and is reduced, causing another substance to be oxidized.

Front

Identify the oxidizing agent in the reaction: 2NaCl + 2H2SO4 + MnO2 → Na2SO4 + MnSO4 + 2H2O + Cl2.

Back

MnO2 is the oxidizing agent.

Front

What is the equilibrium constant (K)?

Back

The equilibrium constant (K) is a number that expresses the ratio of the concentrations of products to reactants at equilibrium for a reversible reaction.

Front

Calculate the equilibrium constant for the reaction: Cl2 + 2e- → 2Cl- and Cu+ + e- → Cu.

Back

K ≈ 2.6 x 10^28 at 298K.

Front

What happens to cell potential when I- concentration is increased in the reaction I2 + 2e- → 2I-?

Back

The cell potential decreases.

Front

What is a redox reaction?

Back

A redox reaction is a chemical reaction involving the transfer of electrons between two species, resulting in changes in oxidation states.

Front

Identify a non-redox reaction: Zn + CuSO4 → ZnSO4 + Cu, 2H2O2 → 2H2O + O2, 2H2 + O2 → 2H2O, H2O + CO2 → H2CO3.

Back

2H2O2 → 2H2O + O2 is not a redox reaction.

Front

In a galvanic cell, which electrode gains mass?

Back

The cathode gains mass.

Front

What is the role of the cathode in a galvanic cell?

Back

The cathode is the electrode where reduction occurs, and it gains electrons from the external circuit.

Front

What is the role of the anode in a galvanic cell?

Back

The anode is the electrode where oxidation occurs, and it loses electrons to the external circuit.