Dissolve 30 g of NaCl salt in 500 ml of water and determine the mass fraction in% of salt in the solution.

1. Knowing that the density of water is 1 g / ml, we find its mass by the formula:

m (H2O) = p * V = 1 g / ml * 500 ml = 500 g

2. Find the mass of the resulting salt solution by the formula:

m (solution) = m (water) + m (salt) = 500 + 30 = 530 g

3. Let’s calculate the mass fraction of salt in the resulting solution by the formula:

w (solution) = m (salt) * 100% / m (solution) = 30 * 100/530 = 5.7%.