Determine the mass fraction of NaCl: 40 cm ^ 3 of water was added to 160 g of a solution with a mass fraction

| August 23, 2021 | education

Determine the mass fraction of NaCl: 40 cm ^ 3 of water was added to 160 g of a solution with a mass fraction of NaCl of 8%. determine the mass fraction of NaCl in the resulting solution

1. The mass fraction of a substance is calculated by the formula:

W = m (substance): m (solution) × 100%,

m (substance) = (m (solution) × W): 100%,

Find the mass of sodium chloride in an 8% solution.

m (substance) = (160 g × 8%): 100% = 12.8 g.

2. Find the mass of the solution after adding 40 cm3 of water.

m (solution) = m (salt) + m (water).

Let’s find the mass of water by the formula.

m = Vp (product of volume and density). Density of water 1g / cm3

m (H2O) = 40 cm3 × 1 g / cm3 = 40 g.

m (solution) 2 = 40 g + 160 g = 200 g.

Let’s find how the mass fraction of a substance in a solution will change.

W = (12.8g: 200g) × 100% = 6.4%.

Answer: 6.4%.



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