Given that the molar mass of NaCl is [tex]$58.44 \, g / mol$[/tex], what is the molarity of a solution that contains 87.75 g of NaCl in 500 mL of solution?

Use molarity [tex]= \frac{\text{moles of solute}}{\text{liters of solution}}[/tex].

A. 0.333 M
B. 0.751 M
C. 1.50 M
D. 3.00 M



Answer :

To find the molarity of the solution, we need to follow a series of steps involving the concepts of moles and molarity. Here is a detailed, step-by-step solution:

1. Identify Given Information:
- Mass of NaCl (solute): 87.75 grams
- Molar mass of NaCl: 58.44 g/mol
- Volume of the solution: 500 milliliters (mL)

2. Convert the Volume of the Solution from Milliliters to Liters:
Since molarity ([tex]\(M\)[/tex]) is defined in terms of liters, we need to convert the volume from milliliters to liters.
[tex]\[ \text{Volume of solution} = 500 \, \text{mL} = \frac{500}{1000} \, \text{L} = 0.500 \, \text{L} \][/tex]

3. Calculate the Number of Moles of NaCl:
To determine the number of moles, we use the molar mass of NaCl. The number of moles ([tex]\(n\)[/tex]) can be calculated using the formula:
[tex]\[ \text{moles of NaCl} = \frac{\text{mass of NaCl}}{\text{molar mass of NaCl}} \][/tex]
Substituting the given values:
[tex]\[ \text{moles of NaCl} = \frac{87.75 \, \text{g}}{58.44 \, \text{g/mol}} \approx 1.5015 \, \text{moles} \][/tex]

4. Calculate the Molarity of the Solution:
Molarity ([tex]\(M\)[/tex]) is defined as the number of moles of solute per liter of solution. Using the formula:
[tex]\[ \text{Molarity} = \frac{\text{moles of solute}}{\text{liters of solution}} \][/tex]
Substituting the values we have:
[tex]\[ \text{Molarity} = \frac{1.5015 \, \text{moles}}{0.500 \, \text{L}} = 3.003 \, \text{M} \][/tex]

So, the molarity of the solution is approximately [tex]\(3.00\, \text{M}\)[/tex].

Therefore, the correct answer is:
[tex]\[ \boxed{3.00 \, \text{M}} \][/tex]

This matches the given correct result from the question:
[tex]\[ (1.501540041067762, 3.003080082135524) \][/tex]

The answer closest to the calculated molarity is [tex]\(3.00 \, \text{M}\)[/tex].