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Calculate the number of moles of calcium chloride CaCI2, that can be obtained from 75g of limestone, CaCO3, in the presence of excess hydrogen chloride.

Equation of reaction

CaCo3(s)+2HCICaCI2(aq)+H2O+CO2(g )

From the equation, 1 mole CaCO3, yields 1 mole CaCI2.

Number of moles of CaCO3 reacted= reacting mass/molar mass

=75g/100g mol-1=0.75mol

0.75 mole CaCO3 will yield 0.75 mole of CaCI2

ASSIGNMENT

1. 30cm2 of a gas, the empirical formula of whivh is CH3 diffuses through a porous pot in 45.2 seconds. 30cm3 of hydrogen does so in 11.7 seconds under the same conditions. What is the molecular formula of the gas?