Which of the following statements about batteries is false c) it is not safe to

ID: 843546 • Letter: W

Question

Which of the following statements about batteries is false

c) it is not safe to recharge a nickel-cadium battery

D) a fuel cell is a galvanic cell for which the reactants are continuoulsy supplied

E) Dry cell batteries are used in flashlights and portable radios.

12) What half reaction occus at the cathod during the electrolysis of molten potassium bromide

A) 2BR-(l) -> Br2(l) + 2e-

C) K+(l) +e- -> K(s)

E) 2H2O(l) +2e- -> H2(g) + 2OH-(l)

17) A lead storage battery involves the following two half reactions:

PbSO4(s) + 2e- -> Pb(s) + SO4^2-(aq); E= -0.36 V

PbO2(s) + 4H+(aq) + SO4^2-(aq) + 2e- -> PbSO4(s) + 2H2O(l); E= 1.69 V

A) -2.05 V and Pb

C) 2.05 V and Pb

D) 2.05 V and PbO2

18) The following reactions take place in a lead storage battery

Discharging: Pb(s) + PbO2(s) +4H(aq) + 2SO4^2-(aq) -> 2PbSo4(s) + 2H2O(l)

Charging: 2PbSO4(s) + 2H2O(l) -> Pb(s)+ PbO2(aq) + 2SO4^2-

Which of the following statements is true.

A) the concentration of H2SO4 increases as the battery discharges

C) Pb is formed at the cathode during charging

D) the mass of Pb decreases during the charging.

19) when the follosing oxidation reduction reaction in acidic solution is balanced what is the lowest whole number coefficient for RB+ (aq)

Rb(s) + Cr2+(aq) Rb+(aq) + Cu(s)

a) 5

b) 4

C) 1

21) what is E of the following cell reaction at 25 degrees C

E cell= 0.460 V Cu(s) / Cu2+(0.012M) // Ag+(0.11M)/Ag(s)

B) 0.640 V C) 0.406V D) 0.460V

22) A lead storage battery involves the following two half reactions:

PbSO4(s) + 2e- -> Pb(s) +SO4^2-(aq); E=-0.36V

PbO2(s) + 4H+(aq) + SO4^2-(aq) + 2e--> PbSO4(s) + 2H2O(l); e=1.69V

In the lead battery during the discharge reaction:

C) Pb is the anode

D) PbO2 is the anode

E) H2SO4 is the cathode

23) For the cell reaction

2MnO4-(aq) + 5H2SO3(aq) <-> 2Mn2+(aq) + 5SO4^2-(aq) + 4H+(aq) + 3H2O

the standard cell potential is 1.34V which changes will result in an increase in potentential?

1) increasing the permangante ion concentration

2) decreasing the pH

3) increasing the sulfurous acid concentration

A) 1 only

C) 3 only

E) 1 and 3

Explanation / Answer