Question

0.0075mole of calcium trioxocrabonate IV is added to 0.015mole of a solution of hydrochloric acid .the volume of gas evolved at stp is​

Answer 1

1mole of gas at STP = 22.4dm3

0.0075 mole of CaCO3 = xdm3

cross multiply;

where 22.4dm3 = 22400cm3

x * 1 = 0.0075 * 22400 → 168cm3

the gas CO2 which evolved was gotten from CaCO3 so we use the number of moles of CaCO3 only