A solution of sodium carbonate was poured into a solution weighing 200 g with a mass fraction of magnesium
A solution of sodium carbonate was poured into a solution weighing 200 g with a mass fraction of magnesium chloride of 19%. determine the mass of the sediment formed.
We draw up the reaction equation and determine the precipitate: MgCl2 + Na2CO3 = MgCO3 + 2NaCl.
The sediment is magnesium carbonate.
1) Find the mass of the dissolved substance of magnesium chloride in its solution. To do this, we multiply the mass fraction of the substance by the mass of the solution and divide by one hundred percent: 200 * 19/100 = 38g.
2) Molar mass of magnesium chloride: 24 + 2 * 35.5 = 95.
3) The amount of magnesium chloride substance: 38/95 = 0.4 mol.
4) According to the reaction equation, there is one mole of magnesium carbonate for one mole of magnesium chloride. This means that the amount of carbonate substance is 0.4 mol.
5) Sediment weight: 0.4 * 84 = 33.6 g – answer.