Question

What is the mass percent concentration of a solution containing 25.0 g NaCl and 155 mL of water? Assume a density of 1.00 g/mL for water.

a) 2.76%
b) 6.20%
c) 13.9%
d) 16.1%

Answer 1

The mass percent concentration of the solution containing 25.0 g NaCl and 155 mL of water is 13.9%. The correct answer is option c).

Step-by-step explanation:

To find the mass percent concentration of the solution, we need to calculate the mass of NaCl and the total mass of the solution. Given that the mass of NaCl is 25.0 g and the volume of water is 155 mL, we can use the density of water (1.00 g/mL) to find the mass of water:

Mass of water = density × volume = 1.00 g/mL × 155 mL = 155 g. The total mass of the solution is the sum of the mass of NaCl and the mass of water: Total mass of the solution = 25.0 g + 155 g = 180 g. Now, we can calculate the mass percent concentration using the formula:

Mass percent concentration = (mass of NaCl / total mass of the solution) × 100%. Mass percent concentration = (25.0 g / 180 g) × 100% = 13.9%.