The answer to this problem is =12
Molarity is moles of solute per litre of solvent. We're given mass of solute, but can convert to moles using the molar mass of NaOH (40 g/mol). There are 10 g / 40 g/mol = 0.25 mol of NaOH in the solution.
M = 0.25 mol / 2.0 L = 0.125M
The second answer (0.13M) is the correct one.
Answer : The mole fraction of NaCl in a mixture is, 0.360
Explanation : Given,
Moles of
= 7.21 mole
Moles of
= 9.37 mole
Moles of
= 3.42 mole
Now we have to calculate the mole fraction of
.

Now put all the given values in this formula, we get:

Therefore, the mole fraction of NaCl in a mixture is, 0.360
C is the answer hope this helps