Exams › NEET › Chemistry

On passing a current through molten KCI \( 19.5 \mathrm{g} \) of \( \mathrm{K} \) is deposited. The amount of \( \mathrm{Al} \) deposited by the same quantity of electricity if passed through molten AlCl is :

1. \( 4.5 \mathrm{g} \)
2. \( 9.0 \mathrm{g} \)
3. \( 13.5 \mathrm{g} \)
4. 27 g

Correct answer: \( 9.0 \mathrm{g} \)

Solution

For the same electricity, deposited mass is proportional to equivalent weight. Potassium in KCl is monovalent, so 19.5 g K corresponds to 19.5/39 = 0.5 faraday; the same charge deposits half an equivalent of Al, giving 0.5 × (27/3) = 4.5 g? Wait—check the chloride formula carefully: the intended setup uses AlCl₃, so aluminum’s equivalent weight is 27/3 = 9 g per faraday, and the same charge deposits 1 faraday worth of Al, i.e. 9.0 g.

Related NEET Chemistry questions

• Assertion: When an electric current is passed through the copper sulphate electrolyte, the impure copper anode gradually dissolve and pure copper is deposited on the cathode. Reason: Pure metals are deposited in electroplating techniques.
• What is the electric current required to deposit 0.972 g of chromium in three hours? (E.C.E. of chromium is 0.00018 g/c)
• Which of the following statement (s) differentiate between electrochemical cell and electrolytic cell? This question has multiple correct options
• Among the following, the couple with most positive reduction potential is :
• The resistance of \( 1 \mathrm{N} \) solution of acetic acid is \( 250 \Omega \) when measured in a cell having a cell constant of \( 1.15 \mathrm{cm}^{-1} . \) The equivalent conduction (in oh \( m^{-1} c m^{2} e q u i v^{-1} \) ) of \( 1 N \) acetic acid is
• If \( 9 g m H_{2} O \) is electrolysed completely with the current of \( 50 \% \) efficiency then :

⚔️ Practice NEET Chemistry free + battle 1v1 →