What precisely is being followed here?
We assume that the stated 50% is measured by volume. Molarity defines the concentration in terms of moles of solute per volume of solution.
To find the moles of NaOH, use: (0.1 moles / L)(0.4 L)
n = 0.04 moles of NaOH
Assuming we start with 1 mL of 50% NaOH solution,
(1 mL solution)(1.525 g/mL)(0.50) = 0.7625 g
Then, the number of moles calculates as follows,[
0.7625 g NaOH x (1 mol / 40 g) = 0.01906 moles of NaOH
The volume of solution required can be determined by:(0.04 moles of NaOH)(1 mL solution / 0.01906 moles of NaOH)
Thus, the needed volume comes out to be 2.09 mL
Answer: 2.09 mL
