# An excess of sodium carbonate solution was added to 200 g of barite water, and a precipitate weighing 8.9 g precipitated.

An excess of sodium carbonate solution was added to 200 g of barite water, and a precipitate weighing 8.9 g precipitated. Determine the mass fraction of barium hydroxide in the initial solution. 1) Let’s compose the reaction equation:
Ba (OH) 2 + Na2CO3 = BaCO3 ↓ + 2NaOH
2) Calculate the amount of barium carbonate and barium hydroxide substance:
n (BaCO3) = m (BaCO3) / M (BaCO3) = 8.9 / 197 = 0.045 mol.
according to the reaction equation
n (Ba (OH) 2) = n (BaCO3) = 0.045 mol
3) Determine the mass of barium hydroxide and its mass fraction in barite water:
m (Ba (OH) 2) = n (Ba (OH) 2) ∙ M (BaCO3) = 0.045 ∙ 171 = 7.695 g.
ω (Ba (OH) 2) = (m (Ba (OH) 2) / m (solution)) ∙ 100% = (7.695 / 200) ∙ 100 = 3.85% Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.