What is the molarity of 6 moles (mol) of [tex]NaCl[/tex] dissolved in [tex]2 L[/tex] of water?

A. [tex]\frac{6 \, \text{mol}}{2 \, \text{L}}[/tex]
B. [tex]\frac{2 \, \text{mol}}{6 \, \text{L}}[/tex]
C. [tex]\frac{2 \, \text{L}}{6 \, \text{mol}}[/tex]
D. [tex]\frac{8 \, \text{ml}}{2 \, \text{L}}[/tex]



Answer :

To determine the molarity of 6 moles of NaCl dissolved in 2 liters of water, we need to use the definition of molarity. Molarity (M) is defined as the number of moles of solute (in this case, NaCl) divided by the volume of solution in liters.

Here’s a step-by-step explanation:

1. Identify the number of moles of solute (NaCl):
- Given: 6 moles of NaCl

2. Identify the volume of the solution in liters:
- Given: 2 liters of water (since water is the solvent, the volume of the solution is the volume of the water here)

3. Apply the formula for molarity (M):
[tex]\[ \text{Molarity (M)} = \frac{\text{moles of solute}}{\text{volume of solution in liters}} \][/tex]

4. Substitute the values into the formula:
[tex]\[ \text{Molarity (M)} = \frac{6 \text{ moles}}{2 \text{ liters}} \][/tex]

5. Perform the division:
[tex]\[ \text{Molarity (M)} = 3.0 \text{ mol/L} \][/tex]

Thus, the molarity of the solution is 3.0 mol/L.

Now, let's examine the given choices to see which one matches this calculation:

A. [tex]\(\frac{6L}{2mol}\)[/tex] - This is incorrect because it inverts the numerator and denominator.
B. [tex]\(\frac{2L}{6mol}\)[/tex] - This is incorrect for the same reason as above.
C. [tex]\(\frac{2mol}{6L}\)[/tex] - This is the inverse of our answer.
D. [tex]\(\frac{8ml}{2L}\)[/tex] - This has different units and does not match the problem context.

None of the choices directly represents the calculation we performed. However, the correct calculation for molarity is our final result, 3.0 mol/L.