13
MCQ (Single Correct Answer)
Hydrogen peroxide is obtained by the electrolysis of .......... .
A
water
B
sulphuric acid
C
hydrochloric acid
D
fused sodium peroxide
14
MCQ (Single Correct Answer)
Which of the following reactions is an example of use of water gas in the synthesis of other compounds?
A
$\mathrm{CH}_4(\mathrm{~g})+\mathrm{H}_2 \mathrm{O}(\mathrm{g}) \xrightarrow[\mathrm{Ni}]{1270 \mathrm{~K}} \mathrm{CO}(\mathrm{g})+\mathrm{H}_2(\mathrm{~g})$
B
$\mathrm{CO}(\mathrm{g})+\mathrm{H}_2 \mathrm{O}(\mathrm{g}) \xrightarrow[\text { Catalyst }]{673 \mathrm{~K}} \mathrm{CO}_2(\mathrm{~g})+\mathrm{H}_2(\mathrm{~g})$
C
$\mathrm{C}_n \mathrm{H}_{2 n+2}+n \mathrm{H}_2 \mathrm{O}(\mathrm{g}) \xrightarrow[\mathrm{Ni}]{1270 \mathrm{~K}} n \mathrm{CO}+(2 n+1) \mathrm{H}_2$
D
$\mathrm{CO}($ g $)+2 \mathrm{H}_2($ g $) \xrightarrow[\text { Catalyst }]{\text { Cobalt }} \mathrm{CH}_3 \mathrm{OH}($ l)
15
MCQ (Single Correct Answer)
Which of the following ions will cause hardness in water sample?
A
$\mathrm{Ca}^{2+}$
B
$\mathrm{Na}^{+}$
C
$\mathrm{Cl}^{-}$
D
$\mathrm{K}^{+}$
16
MCQ (Single Correct Answer)
Which of the following compounds is used for water softening?
A
$\mathrm{Ca}_3\left(\mathrm{PO}_4\right)_2$
B
$\mathrm{Na}_3 \mathrm{PO}_4$
C
$\mathrm{Na}_6 \mathrm{P}_6 \mathrm{O}_{18}$
D
$\mathrm{Na}_2 \mathrm{HPO}_4$
17
MCQ (Single Correct Answer)
Elements of which of the following group(s) of periodic table do not form hydrides?
A
Groups 7, 8, 9
B
Group 13
C
Groups $15,16,17$
D
Group 14