Question

Calculate weight,volume and number of moles of gas liberated when $6.6g$ of ammonium salt is heated with slaked lime. $Ca = 40,N = 14,H = 1,S = 32,O = 16$.

Answer 1

When atoms joined together in a definite ratio then a molecule is formed. Each atom has a specific atomic weight; this is known as atomic weight and we calculate the weight of a molecule then its molecular mass.

Complete step by step answer:
The mass of an a single atom is known as atomic mass and atomic is measured in $amu$ that is known as atomic mass unit and atomic mass in case of isotopes (When an element having same atomic number but have different atomic mass this is known as isotopes) is different for different isotopes of same element.
Molecular mass may be defined as when we add the atomic mass of different elements present in a molecule that is known as molecular mass. And the molecular mass is measured in gram per mol ($g/mol$).
When ammonium salt $\left[ {{{(NH)}_2}S{O_4}} \right]$ is heated with slaked lime $\left[ {Ca{{(OH)}_2}} \right]$ is heated then calcium sulphate $\left( {CaS{O_4}} \right)$ and water $\left( {{H_2}O} \right)$ and ammonia $\left( {N{H_3}} \right)$ is formed. The chemical reaction is –
${(N{H_4})_2}S{O_4} + \left[ {Ca{{(OH)}_2}} \right] \to CaS{O_4} + 2{H_2}O + 2NH_3^{}$
Molecular mass of ammonium salt is -$\left[ {{{(NH)}_2}S{O_4}} \right]$ is $\left[ {(14 + 1 \times 4) \times 2 + 32 + 4 \times 16} \right]$=$132$
$132g$ of ammonium salt produced ammonia is = $32g$
So $6.6g$ of ammonium salt produced ammonia is=$32/132 \times 6.6$
So $6.6g$ of ammonium salt produced ammonia is= $1.70g$
Number of moles of ammonia is = given mass of ammonia/molecular mass of ammonia
Number of moles of ammonia is =$1.70/17 = 0.1mol$
And volume of ammonia gas is = $0.1 \times 22.4l = 2.24l$
And volume of ammonia gas is =$2.24 \times 1000 = 2240ml$

Hence weight of ammonium salt produced ammonia is= $1.70g$ and Number of moles of ammonia is =$1.70/17 = 0.1mol$, and volume of ammonia gas is =$2.24 \times 1000 = 2240ml$.

Note:
The melting point of slaked lime is ${580^O}C$and the molar mass of slaked lime is $74.0g/mol$.
Slaked lime is a water soluble compound and is used in plasters and cements.
Water behaves as an amphipole while it behaves as an electrophile as well as nucleophile.
Salt is formed when acid and base react with each other.