Answer:
Mass of sodium carbonate required = 45.58 g
Explanation:
Given data:
Mass of sodium carbonate required = ?
Mass of barium carbonate produced = 85.0 g
Solution:
Chemical equation:
Na₂CO₃ + BaCl₂  →  BaCO₃ + 2NaCl
Number of moles of BaCO₃:
Number of moles = mass/ molar mass
Number of moles = 85.0 g/ 197 g/mol
Number of moles = 0.43 mol
Now we will compare the moles of sodium carbonate with barium carbonate.
           BaCO₃       :        Na₂CO₃
             1         :          1
            0.43       :        0.43
Mass of Na₂CO₃:
Mass = number of moles × molar mass
Mass = 0.43 mol × 106 g/mol
Mass = 45.58 g