✓ Board-verified
Chemistry · 2025 · 3 marks
CBSE 2025 · Region 6 · Set 1 · Q24
Give reasons for the following: (a) The pH of aqueous NaCl increases when it is electrolysed. (b) Unlike dry cell, mercury cell has a constant cell…
Give reasons for the following:
(a)
The pH of aqueous NaCl increases when it is electrolysed.
(b)
Unlike dry cell, mercury cell has a constant cell potential through its lifetime.
(c)
Conductivity of solution decreases with dilution.
Marking-scheme solution
(a)
Because of the formation of NaOH / Due to the formation of OH⁻ ions.
(b)
Because the overall reaction does not involve any ion in solution whose concentration can change during its life time.
(c)
Because the number of ions per unit volume that carry current in a solution decreases.
All Electrochemistry questions2025 question paperNCERT solutions: ElectrochemistryPractice Electrochemistry →
More from Electrochemistry
- Kohlrausch gave the following relation for strong electrolytes: Λ_m=Λ_m^°-A √C Which of the following equality holds true?2025 · asked 2×
- Assertion: E_Cu^° 2+/ Cu is positive (+0.34 V). Reason (R): Copper has high Δ_a H^° and low Δ_hyd H^°.2023 · asked 2×
- During the electrolysis of aqueous NaCl, the cathodic reaction is:2024
- Calculate the standard Gibbs energy (Δ_r G^°) of the following reaction at 25 °C: 3 + 2 Au( s)+Ca^2+(1 M) → Au^3+(1 M)+Ca( s); E_Au^3+ / Au^°=+1.5 V,…2025
- (i) What should be the signs (positive/negative) for E^°_Cell and Δ G^° for a spontaneous redox reaction occurring under standard conditions? (ii)…2023
- Batteries and fuel cells are very useful forms of galvanic cell. Any battery or cell that we use as a source of electrical energy is basically a…2024
- (i) Why on dilution the Λ_m of CH_3 COOH increases very fast, while that of CH_3 COONa increases gradually? (ii) What happens if external potential…2022
- During electrolysis of dilute H_2 SO_4, using platinum electrodes, the gas evolved at the anode is:2025
CBSE Class 12 Chemistry past-paper question from the 2025 board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.