Calculate the mass fraction of salt in a solution obtained by adding 40 g of salt to 350 g

Calculate the mass fraction of salt in a solution obtained by adding 40 g of salt to 350 g of a solution with a mass fraction of 20% and evaporating 50 g of water

1. Calculate the mass of salt contained in the original solution:

mout (salt) = wout (salt) * mout (solution) = 0.2 * 350 = 70 g.

2. Find the total mass of salt:

mtot (salt) = mout (salt) + mdb (salt) = 70 + 40 = 110 g.

3. Determine the mass of the resulting solution:

mpol (solution) = mout (solution) + mad (salt) – mout (water) = 350 + 40 – 50 = 340 g.

4. Let’s calculate the mass fraction of salt in the resulting solution:

wp (salt) = mtot (salt): mpol (solution) = 110: 340 = 0.3235 or 32.35%.

Answer: 32.35%.