Question

In the laboratory, a student dilutes 12.3 mL of a 11.9 M nitric acid solution to a total volume of 250.0 mL. What is the concentration of the diluted solution?

Answer 1

Equal molars of any two solutions react in equal volumes. Mathematical form of this statement is the molarity equation.

Answer 2

Dilution reduces concentration but keeps moles of solute constant. 

Use  $M_1{V}_1=M_2{V}_2$ for calculations. 

Given:

• Initial volume ($V_1$) = 12.3 mL

• Initial concentration ($M_1$) = 11.9 M

• Final volume ($V_2$) = 250.0 mL

Formula:

$$M_1{V}_1=M_2{V}_2$$

Calculation:

$$M_2=\frac{M_1{V}_1}{V_2}=\frac{(11.9\text{M})(12.3\text{mL})}{250.0\text{mL}}$$$$M_2=\frac{146.37}{250.0}=0.58548\text{M}$$

Rounding (3 sig figs):

$$M_2=\mathbf{0.585}\text{M}$$

Final Answer:
The diluted nitric acid concentration is 0.585 M.