pBlock ElementsII - Result Question 99
####95. Draw balanced equations for
(i) the preparation of phosphine from $CaO$ and white phosphorus.
(ii) the preparation of ammonium sulphate from gypsum, ammonia and carbon dioxide.
$(1990,2 M)$
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Solution:
- (i) $15 CaO+4 P _4 \stackrel{\Delta}{\longrightarrow} 5 Ca _3 P _2+3 P _2 O _5 \uparrow$
$\left[Ca _3 P _2+6 H _2 O \longrightarrow 3 Ca(OH) _2+2 PH _3 \uparrow\right] \times 5$
$15 CaO+4 P _4+30 H _2 O \longrightarrow 15 Ca(OH) _2$
$$ +3 P _2 O _5 \uparrow+10 PH _3 \uparrow $$
(ii) $2 NH _3+CO _2+H _2 O \longrightarrow\left(NH _4\right) _2 CO _3$ $CaSO _4+\left(NH _4\right) _2 CO _3 \longrightarrow CaCO _3 \downarrow+\left(NH _4\right) _2 SO _4$ gypsum
$\overline{CaSO _4+2 NH _3+CO _2+H _2 O \longrightarrow CaCO _3 \downarrow+\left(NH _4\right) _2 SO _4}$
