What mass of calcium chloride is needed to react with 2.50 grams of sodium
carbonate?
Na2CO3 +CaCl2
+2 Naci + CaCO3

2.8 g of CaCl2 is needed to react with 2.50 g of sodium carbonate.

Explanation:

The balanced equation is given as

              Na2CO3 +CaCl2  ----> 2 Nacl + CaCO3

Use the balanced equation to determine the mole ratios between  CaCO 3  and  CaCl 2 .

Calcium carbonate and calcium chloride.

                     

Determine the moles of each reactant by dividing the given masses by their molar masses.

2.50 g of CaCO3 (1 mol of CaCO3 / 100.1 g of CaCO3) = 0.025 g of CaCO3.

Determine the mass of  CaCl 2  produced by each reactant by multiplying the moles of each reactant times the mole ratios with  CaCl 2  in the numerator. Then multiply the result by the molar mass of  CaCl 2  ( 111 g/mol ) .

0.025 g of CaCO3 (1 mol of CaCl2 / 1 mol of CaCO3) (111 g of CaCl2 / 1 mol of CaCl2)  = 2.8 g of CaCl2.