Question

$1.64g$ of a mixture of calcium carbonate and magneisum carbonate were dissolved in $50mL$ of $0.8N$ hydrochloric acid. The excess of the acid required $16mLN/4$ sodium hydroxide solution for neutralisation. Find out the percentage composition of the mixture of two carbonates.

Answer 1

$CaC{O}_3+2HCl\to CaC{l}_2+2H_{2}O$

$MgC{O}_3+2HCl\to MgC{l}_2+H_{2}O$

$2x+2y=\frac{(50\ast 0.8)-916\ast 0.25)}{1000}$

$x+y=0.018$

$x+100+y\ast 84=1.64$

From(i) and (ii)

$100(0.018-y)+84y=1.64$

$\to y=0.01$

$x=0.018-0.01=0.008$

% $CaC{O}_3=\frac{0.008\ast 100}{1.64}\ast 100=48.78$ %

% $MgC{O}_3=\frac{0.01\ast 84}{1.64}\ast 100=51.22$ %