Answer:
2.62g
Explanation:
Given parameters:
Mass of Na₂CO₃ = 2.5g
Unknown:
Mass of CaCl₂ = ?
Solution:
We have to work from the known to the unknown using their molar relationships.
The known is the given mass of Na₂CO₃.
We must make sure the reaction equation is balanced before we start working with it;
Na₂CO₃ + CaCl₂ → 2NaCl + CaCO₃
Now,
Number of moles of Na₂CO₃ = [tex]\frac{mass}{molar mass}[/tex]
Molar mass of Na₂CO₃ = 2(23) + 12 + 3(16) = 106g/mol
Number of moles = [tex]\frac{2.5}{106}[/tex] = 0.024mole
1 mole of Na₂CO₃ reacted with 1 mole of CaCl₂
0.024mole of Na₂CO₃ will react with 0.024mole of CaCl₂
Mass of CaCl₂ = number of moles x molar mass
Molar mass of CaCl₂ = 40 + 2(35.5) = 111g/mole
Mass of CaCl₂ = 0.024 x 111 = 2.62g
