CHEM101-EE group

The standard reduction potential for the half cell reaction are: Fe ⁺⁺ = Fe ; E⁰ = -0.44V and Zn ⁺⁺ + 2e^- = Zn ; E⁰ = -0.76V , which one of the is the strong oxidizing agent?

• Fe ⁺⁺

• Fe

• Zn ⁺⁺

• Zn

The cell which can be restored to nearly new condition by reversing the current flow is called…………………………

(a)  

What is indicated when a chemical cell’s voltage (E°) has dropped to zero?

• the concentration of the reactants has increased

• he concentration of the products has decreased

• the cell reaction has reached equilibrium

• the cell reaction has completely stopped

The standard reduction potentials in volts for Pb²⁺ and Ag+ are –0.13 and +0.80, respectively. Calculate E° in volts for a cell in which the overall reaction is Pb + 2Ag+ → Pb²⁺ + 2Ag

• 1.73

• 0.67

• 0.93

• 1.47

The salt bridge in the electrochemical cell serves to

• increase the rate at which equilibrium is attained

• increase the voltage of the cell

• maintain electrical neutrality

• increase the oxidation/reduction rate

The standard reduction potentials of Cu²⁺ and Ag+ in V are +0.34 and +0.80, respectively. Determine the value of E in volts for the following cell at 25°C Cu | Cu²⁺ (1.00 M) || Ag+ (0.0010 M) | Ag

• 0.37 V

• 0.55 V

• – 0.48 V

• 0.28 V

The advantages of fuel cells include

• they can be recharged by the addition of more material to be oxidized and/or reduced

• they can be made to produce little or no harmful pollutants

• they can be made to run very quietly

• all of the above

Which of the following statements associated with batteries is incorrect?

• in a dry cell, the reaction Zn → Zn²⁺ continues to occur even when the battery is not being used

• secondary batteries are rechargeable

• the cell reaction in a primary battery is not reversible

• electrodes with greater surface area give a greater potential

Which of the following salt has higher solubility in water?

• BaF₂ (K_sp= 1.7 × 10^-6)

• CaF₂ (K_sp = 1.7 ×10^-10)

• CaSO₄ (K_sp = 2.4 × 10^-5)

• BaSO₄ (K_sp = 1.1 × 10^-10)

Mixing same volume of 0.1M NaOH with 0.2M CH₃COOH results a solution possessing pH of (a)   [ given, dissociation constant (K_a) of CH₃COOH is 2.8×10^-5]