Question

What happens when:
(i) Water reacts with cyanamide of calcium.
(ii) Peroxosulphuric acid is hydrolysed.
(iii) Moist silver oxide reacts with $H_{2}O_{2}$.

Answer 1

i Calcium cyanamide, CaCN2, reacts with water to form calcium carbonate and ammonia; CaCN2(s)+3H2O(l)-->CaCO3(s)+2NH3(g). a) How many grams of water are needed to react with 75.0 g of CaCN2? b) How many grams of NH3 are produced from 5.24 g of CaCN2? c) How many grams of CaCO3 form if 155 g of water reacts?
ii

Answer 2

"i) Water reacts with cyanamide of calcium. The following reactions takes place

$\quad \quad { CaC{ N }_{ 2 } }\quad +\quad 6{ H }_{ 2 }O_{ (cold) }\quad \longrightarrow [Ca({ H }_{ 2 }O)_{ 6 }]^{ 2+ }\quad +\quad CN_{ 2 }^{ 2- }$

$C{ N }_{ 2 }^{ 2+ }\quad +\quad H_{ 2 }O\quad \longrightarrow \quad HC{ N }_{ 2 }^{ - }\quad +\quad O{ H }^{ - }$

$CaC{ N }_{ 2 }\quad +\quad 3H_{ 2 }O_{ (hot) }\quad \longrightarrow \quad Ca(OH)_{ 2 }\quad +\quad C(NH_{ 2 })_{ 2 }O\quad _{ (70 }\circ _{ C) }$

$CaC{ N }_{ 2 }\quad +\quad 2H_{ 2 }O_{ (vapour) }\quad \longrightarrow \quad CaCO_{ 3 }\quad +\quad 2NH_{ 3 }\quad _{ (300 }\circ _{ C) }$

ii) Peroxosulphuric acid is hydrolysed which is shown in below picture.

iii) Moist silver oxide reacts with $H_{ 2 }{ O }_{ 2 }$.

$\quad \quad { { Ag }_{ 2 } }O_{ (s) }\quad +\quad { H }_{ 2 }O_{ 2 }_{ (l) }\quad \longrightarrow \quad 2Ag_{ (s) }\quad +\quad H_{ 2 }O_{ (l) }\quad +\quad O_{ 2 }_{ (g) }$"