11
MCQ (Single Correct Answer)
In the synthesis of sodium carbonate, the recovery of ammonia is done by treating $\mathrm{NH}_4 \mathrm{Cl}$ with $\mathrm{Ca}(\mathrm{OH})_2$. The by-product obtained in this process is
A
$\mathrm{CaCl}_2$
B
NaCl
C
NaOH
D
$\mathrm{NaHCO}_3$
12
MCQ (Single Correct Answer)
When sodium is dissolved in liquid ammonia, a solution of deep blue colour is obtained. The colour of the solution is due to
A
ammoniated electron
B
sodium ion
C
sodium amide
D
ammoniated sodium ion
13
MCQ (Single Correct Answer)
By adding gypsum to cement
A
setting time of cement becomes less
B
setting time of cement increases
C
colour of cement becomes light
D
shining surface is obtained
14
MCQ (Single Correct Answer)
Dead burnt plaster is
A
$\mathrm{CaSO}_4$
B
$\mathrm{CaSO}_4 \cdot \frac{1}{2} \mathrm{H}_2 \mathrm{O}$
C
$\mathrm{CaSO}_4 \cdot \mathrm{H}_2 \mathrm{O}$
D
$\mathrm{CaSO}_4 \cdot 2 \mathrm{H}_2 \mathrm{O}$
15
MCQ (Single Correct Answer)
Suspension of slaked lime in water is known as
A
lime water
B
quick lime
C
milk of lime
D
aqueous solution of slaked lime