Question

How many grams of solute are in 250mL of 2.0M of CaCi2?

Answer 1

Answer:

1) 55.49 g.

2) 383.37 g.

Explanation:

Molarity is the no. of moles of solute in a liter of the solvent.

Molarity (M) = (n of solute)/(Volume of the solution (L))= (mass/molar mass)solute x (1000/V of the solution(ml))

1) How many grams of solute are in 250 mL of 2.0 M of CaCl₂?

∵ M = (mass/molar mass)CaCl₂ x (1000/V of the solution(ml))

M of CaCl₂ = 2.0 M, V of the solution = 250.0 mL, molar mass of CaCl₂ = 110.98 g/mol.

∴ mass of CaCl₂ = (M)(V of the solution (ml))(molar mass of CaCl₂)/1000 = (2.0 M)(250.0 mL)(110.98 g/mol)/(1000) = 55.49 g.

2) How many grams of solute are in 500.0 mL of a 4.4 M solution of K₂SO₄?

∵ M) = (mass/molar mass)K₂SO₄ x (1000/V of the solution(ml))

M of CaCl₂ = 4.4 M, V of the solution = 500.0 mL, molar mass of K₂SO₄ = 174.259 g/mol.

∴ mass of K₂SO₄ = (M)(V of the solution (ml))(molar mass of K₂SO₄)/1000 = (4.4 M)(500.0 mL)(174.259 g/mol)/(1000) = 383.37 g.