The cathode reaction in the dry cell will be

Question

The cathode reaction in the dry cell will be (A)  Zn(s) arrow Zn2+ + 2e-  (B)  MnO2 + NH+4 + e- arrow MnO(OH) + NH3 (C)  Zn(Hg) + 2OH- arrow ZnO(s) + H2O + 2e- (D) MnO(OH) + NH3 - arrow MnO2 + NH+4 + 2e-

Tardigrade Admin · Accepted Answer

Correct answer is (b) MnO2 + NH+4 + e- arrow MnO(OH) + NH3

Q. The cathode reaction in the dry cell will be

$Z n_{(s)} \to Z n^{2 +} + 2 e^{-}$

$M n O_{2} + N H_{4}^{+} + e^{-} \to M n O (O H) + N H_{3}$

$Z n (H g) + 2 O H^{-} \to Z n O_{(s)} + H_{2} O + 2 e^{-}$

$M n O (O H) + N H_{3}^{-} \to M n O_{2} + N H_{4}^{+} + 2 e^{-}$

Correct answer is (b) $M n O_{2} + N H_{4}^{+} + e^{-} \to M n O (O H) + N H_{3}$

Q. The cathode reaction in the dry cell will be

Zn(s)​→Zn2++2e−

MnO2​+NH4+​+e−→MnO(OH)+NH3​

Zn(Hg)+2OH−→ZnO(s)​+H2​O+2e−

MnO(OH)+NH3−​→MnO2​+NH4+​+2e−

Correct answer is (b) MnO2​+NH4+​+e−→MnO(OH)+NH3​

$Z n_{(s)} \to Z n^{2 +} + 2 e^{-}$

$M n O_{2} + N H_{4}^{+} + e^{-} \to M n O (O H) + N H_{3}$

$Z n (H g) + 2 O H^{-} \to Z n O_{(s)} + H_{2} O + 2 e^{-}$

$M n O (O H) + N H_{3}^{-} \to M n O_{2} + N H_{4}^{+} + 2 e^{-}$

Correct answer is (b) $M n O_{2} + N H_{4}^{+} + e^{-} \to M n O (O H) + N H_{3}$