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Science · 2023 · 3 marks
CBSE 2023 · Region 4 · Set 1 · Q27
(i) While electrolysing water before passing the current some drops of an acid are added. Why? Name the gases liberated at cathode and anode. Write…
(i)
While electrolysing water before passing the current some drops of an acid are added. Why? Name the gases liberated at cathode and anode. Write the relationship between the volume of gas collected at anode and the volume of gas collected at cathode.
(ii)
What is observed when silver chloride is exposed to sunlight? Give the type of reaction involved.
Marking-scheme solution
(i) • To increase the conductivity of water
Hydrogen - cathode Oxygen - anode
Anode : Cathode
$\displaystyle 1$: $\displaystyle 2$
/Volume of hydrogen liberated at cathode is twice that of oxygen liberated at anode.
(ii) • White silver chloride turns grey
Decomposition reaction / Photolytic Decomposition
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CBSE Class 10 Science past-paper question from the 2023 board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.