# Find the mass fraction of sodium chloride in the solution obtained by dissolving 15 g of this salt in 235 ml of water.

November 14, 2020 | Education

| Given: m (NaCl) = 15 g, V (H2O) = 235 ml.

Find: ω (NaCl) -?

Decision.

1. Let’s calculate the mass of water by the formula: m = ρ • V.

M (Н2О) = ρ (Н2О) • V (Н2О) = 1 g / ml • 235 ml = 235 g. We see that for water the volume is equal to the mass, therefore this action is not necessary.

2. Calculate the mass of the solution:

m (solution) = m (H2O) + m (NaCl) = 235 g + 15 g = 250 g.

3. Let’s calculate the mass fraction of sodium chloride in solution:

ω (NaCl) = m (NaCl) / m (solution) = 15 g: 250 g = 0.06, or,

multiplying this number by 100%, we get 6%.

Answer: 6%.

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.