Question

14. How many grams of NaCl are contained in 0.350 kg of a

0.238 m solution of sodium chloride?
83.3 g
0
4.87 g
4.87 g
O
13.9 g
o
1.43 g

Answer 1

4.87g

Step-by-step explanation:

Step 1:

Data obtained from the question. This includes the following:

Mass of solution = 0.35kg

Molality = 0.238 m

Mass of NaCl =..?

Step 2:

Determination of the number of mole of NaCl in the solution.

Molality of a solution is simply defined as the mole of solute per unit kg of the solvent. It is given as:

Molality = mol of solute /mass of solvent (kg)

With the above formula, we calculate the mole of NaCl present in the solution as follow:

Molality = mol of solute /mass of solvent (kg)

0.238 = mol of NaCl /0.35

Cross multiply

mol of NaCl = 0.238 x 0.35

mol of NaCl = 0.0833 mol

Step 3:

Determination of the mass of NaCl in 0.0833 mol of NaCl.

This is illustrated below:

Number of mole NaCl = 0.0833 mol

Molar Mass of NaCl = 23 + 35.5 = 58.5g/mol

Mass of NaCl =..?

Mass = number of mole x molar Mass

Mass of NaCl = 0.0833 x 58.5

Mass of NaCl = 4.87g

Therefore, 4.87g of NaCl is contained in the solution.