Answer to Question #88216 in Physical Chemistry for Prajwal

Question

A sample of limestone contains 60% CaCO3. Calculate the amount of limestone that will be required to produce just sufficient CO2 to convert 1litre of 1N NaOH into Na2CO3

Answer 1

n(NaOH) = C * V = 1 mol;

m(NaOH) = n(NaOH) * M(NaOH) = 1 * 40 = 40 g;

2NaOH + CO 2 = Na 2 CO 3 + H 2 O; n(CO 2 )≥n(NaOH);

If n(CO 2 ) = 2 mol;

CaCO 3 = CaO + CO 2 ;

n(CaCO 3 ) = n(CO 2 ) = 2 mol;

m(CaCO 3 ) = n(CaCO 3 ) * M(CaCO 3 ) = 2*100 = 200 g;

m(limestone) = m(CaCO 3 )/ w(CaCO 3 ) = 200/0.6 = 333 g.

Answer: 333 g.