What is the molarity of a solution made by dissolving 36.29 g of NaCl in 2.30 L of solution?

A) 15.78 M NaCl
B) 0.0634 M NaCl
C) 0.270 M NaCl
D) 2.70 M NaCl



Answer :

To find the molarity of the NaCl solution, we need to follow these steps:

1. Calculate the number of moles of NaCl present:
- First, we need to know the mass of NaCl (given as 36.29 grams) and its molar mass. The molar mass of NaCl (sodium chloride) is 58.44 g/mol.
- The number of moles ([tex]\( n \)[/tex]) is calculated using the formula:
[tex]\[ n = \frac{\text{mass}}{\text{molar mass}} \][/tex]
Substituting the given mass and molar mass:
[tex]\[ n = \frac{36.29 \text{ g}}{58.44 \text{ g/mol}} \approx 0.6209787816563997 \text{ moles} \][/tex]

2. Calculate the molarity of the NaCl solution:
- Molarity ([tex]\( M \)[/tex]) is defined as the number of moles of solute per liter of solution. This can be calculated using the formula:
[tex]\[ M = \frac{\text{moles of solute}}{\text{volume of solution in liters}} \][/tex]
Given that the volume of the solution is 2.30 liters:
[tex]\[ M = \frac{0.6209787816563997 \text{ moles}}{2.30 \text{ L}} \approx 0.2699907746332173 \text{ M} \][/tex]

3. Compare the calculated molarity to the given options:
- The calculated molarity is approximately 0.270 M NaCl.
- Reviewing the multiple-choice options, we see that:
- A) 15.78 M NaCl
- B) 0.0634 M NaCl
- C) 0.270 M NaCl
- D) 2.70 M NaCl

Given that the calculated molarity (0.270 M NaCl) matches one of the provided choices:

The correct answer is C) 0.270 M NaCl.