If 20 kg of calcium carbonate was reacted with excess sodium chloride in the following reaction (2NaCl+CaCo3-->Na2Co3+CaCl2) what is the maximum mass of sodium carbonate that could be made?

1)Always write out the reaction first;

2NaCl+CaCo3-->Na2Co3+CaCl2  

2)Now underneath calculate the Relative Formula Mass using a periodic table for each of the compounds. 

CaCo3=100/ Na2Co3=106

3)Now always write out the formula you intend to use;

Moles= Mass of substance/ Relative formula mass

4)Always convert everything to grams so 20kg=20000g

Moles= 20 000/100

Moles= 200

5)Ratio of CaCo3 toNa2Co3 is 1:1 as seen in equation

so 200 moles= mass/ 106

therefore 200x106= mass

21200 mass in grams 

or 21.2 kg