A standard solution of 0.243 M NaOH was used to determine the concentration of a hydrochloric acid solution. If 46.33 mL of NaOH is needed to neutralize 10.00 mL of the acid, what is the molar concentration of the acid in the original solution?
A) 0.243 M
B) 0.200 M
C) 1.13 M
D) 0.563 M
E) 0.0313 M

Question

Quizplus · Accepted Answer

First, we need to determine the moles of NaOH used:
moles NaOH = M NaOH x L NaOH
moles NaOH = 0.243 M x 0.04633 L
moles NaOH = 0.01122719 mol

Since the reaction is a 1:1 ratio of acid to base, this means that the molarity of the acid is also 0.01122719 mol/L.

Now, we need to calculate the molarity of the acid in the original solution. To do this, we use the formula:
M1V1 = M2V2

where M1 is the molarity of the NaOH solution, V1 is the volume of NaOH used, M2 is the molarity of the acid, and V2 is the volume of the acid used.

Plugging in the values we know:
(0.243 M)(0.04633 L) = M2(0.01000 L)
M2 = 1.11983 mol/L = 1.13 M

Therefore, the molar concentration of the acid in the original solution is 1.13 M.

A Standard Solution of 0