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Science · 2026 · 1 mark
CBSE 2026 · Region 2 · Set 3 · Q19
Which of the following are decomposition reactions? (i) 2 KClO_3 → 2 KCl +3 O_2 (ii) MgO + H_2 O → Mg ( OH )_2 (iii) 2 H_2 O → H_2+ O_2 (iv) Zn +…
Which of the following are decomposition reactions?
(i)
$\displaystyle 2 \mathrm{KClO}_{3} \longrightarrow 2 \mathrm{KCl}+3 \mathrm{O}_{2}$
(ii)
$\displaystyle \mathrm{MgO}+\mathrm{H}_{2} \mathrm{O} \longrightarrow \mathrm{Mg}(\mathrm{OH})_{2}$
(iii)
$\displaystyle 2 \mathrm{H}_{2} \mathrm{O} \longrightarrow \mathrm{H}_{2}+\mathrm{O}_{2}$
(iv)
$\displaystyle \mathrm{Zn}+\mathrm{CuSO}_{4} \longrightarrow \mathrm{ZnSO}_{4}+\mathrm{Cu}$
Official answer
(C)
(i) and (iii)
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