Question

Calculate the percent by mass of a solution made from 17 g NaCl (the solute) and 62 g water. Units are optional.

a) 21.5%
b) 27.4%
c) 35.4%
d) 40.8%

Answer 1

The percent by mass of the solution made from 17 g NaCl and 62 g water is calculated as 21.52%, which is rounded to 21.5% (option a).

Step-by-step explanation:

To calculate the percent by mass of a solution made from 17 g NaCl and 62 g water, you first determine the total mass of the solution, which is the sum of the mass of the solute (NaCl) and the mass of the solvent (water).

Total mass of solution = mass of NaCl + mass of water = 17 g + 62 g = 79 g

Next, use the percent by mass formula:

Percent by mass = (mass of solute / total mass of solution) x 100%

Percent by mass of NaCl = (17 g / 79 g) x 100% = 21.52%

The closest answer to 21.52% is option (a) 21.5%.