Answer to Question #160636 in General Chemistry for Dexther Villanueva

Question

A sample of impure calcite (CaCO3, molar mass = 100.1g) which weighs 0.4950g is dissolved in 50.00ml of standard acid and the excess acid is titrated with 5.25ml of standard base. 1.000ml of the acid is equivalent to 0.005300g Na2CO3 (molar mass = 106.0); 1.050ml acid = 1.000ml base. Calculate the percentage of CaCO3 in the sample?

A. 23.00%

B. 44.99%

C. 45.50%

D. 22.63%

E. none of the given answers

Answer 1

% of Caco3 =

mass of CaCO₃ ×100 / Total mass .

A sample of impure calcite (CaCO3, molar mass = 100.1g) which weighs 0.4950g is dissolved in 50.00ml of standard acid and the excess acid is titrated with 5.25ml of standard base. 1.000ml of the acid is equivalent to 0.005300g Na2CO3 (molar mass = 106.0);