Secondary Cells

Q.

The standard reduction potential of the reaction at 25° C , $H_{2}O+e^{-}$ gives half ${\frac{1}{2}H}_2\left(g\right)+O{H}^{-}$ is -0.8277 V. The equilibrium constant for the reaction $H_{2}O$ reversible $H_3{O}^{+}+O{H}^{-}$ at 25° C is

Q. 6. 2g of NaOH per 250ml of solution is added is to a buffer solution of buffer capacity 0.2.Then the charge in pH is?

Q.

Given the standard reduction potentials:

Zn²⁺/Zn = - 0.74 V, Cl₂/Cl^- = 1.36 V, H⁺/1/2H₂ = 0 V and Fe³⁺/Fe²⁺ = 0.77 V.
The order of increasing strength as reducing agent is

1. Cl^-, Fe²⁺, H_2, Zn

2. Cl^-, Fe²⁺, Zn, H₂

3. H₂, Zn, Fe²⁺, Cl^-

4. Zn, H₂, Fe²⁺, Cl^-

Q. 1. A galvanic cell is set up with a copper electrode in contact with 0.1M CuSO4(aq) and a lead electrode in contact with 0.1M Pb(NO3)2(aq), respectively, at 25ºC. The standard reduction potentials are: Pb2+ + 2 e- → Pb Eº= -0.13 V Cu2+ + 2 e- → Cu Eº= +0.34 V If H2SO4 is being added to the half-cell containing Pb(NO3)2 (thus forming a precipitate of PbSO4) until the final concentration of SO42- ions in solution is 2.4 x 10-1 M, what is the cell potential in Volt? Assume the volume of the the half-cell does not change upon addition of H2SO4. Ksp(PbSO4)=6.3 x 10-7.

Q. We know that at equilibrium Ecell is zero but E(naught)cell is not zero?

Q. 9. Read the given statements carefully: Statement-1: Distilled water does not conduct electricity. Statement-2: Rain water conducts electricity due to the presence of inorganic acids like nitric acid. Now, choose the correct option. A) Both the statements are correct. B) Both the statements are incorrect. C) Only statement-1 is correct . D) Only statement-2 is correct.

Q. Which of the following is TRUE in case of recharging a Lead Storage Battery?

1. $PbS{O}_4\left(s\right)+2e^{-}\to Pb\left(s\right)+S{O}_4^{2-}\left(aq\right)$
2. $PbS{O}_4\left(s\right)+2H_{2}O\to Pb{O}_2\left(s\right)+S{O}_4^{2-}\left(aq\right)+4H^{+}\left(aq\right)+2e^{-}$
3. $Pb\left(s\right)+S{O}_4^{2-}\left(aq\right)\to PbS{O}_4\left(s\right)+2e^{-}$
4. $Pb{O}_2\left(s\right)+S{O}_4^{2-}+4H^{+}\left(aq\right)+2e^{-}\to PbS{O}_4\left(s\right)+2H_{2}O\left(l\right)$

Q.

Calculate cell potential of the following cell

Zn_(s) | Zn²⁺ || Pb²⁺ | Pb_(s)

Given E^○_Pb/Pb²⁺=+0.12V, E^○_Zn/Zn²⁺=+0.76V

Q. Which of the following is/are true regarding galvanic cell representation?

1. Single vertical line indicates the phase boundary
2. Cell representation of cathode $H_2$ electrode is
   $Pt\left(s\right)|H_2\left(g\right)|H^{+}\left(aq\right)$
   
3. Pressure of gas is indicated in bracket after the substance
4. In gas electrode, gas is indicated before electrode for cathode

Q. We know that cathode itself is an electron donor then why we take the gas inside CRT to find the e/m ratio?

Q. Explain the energy conversion n its factors that play an important role in the stability of molecule in relation to potential energy n internuclear distance.