## A solution is made by adding 23.1 mL of concentrated nitric acid ( 70.4 wt% , density 1.42 g/mL ) to some water in a volumetric flask, and t

Question

A solution is made by adding 23.1 mL of concentrated nitric acid ( 70.4 wt% , density 1.42 g/mL ) to some water in a volumetric flask, and then adding water to the mark to make exactly 200 mL of solution. Calculate the concentration of this solution in molarity.

in progress 0
1 year 2021-08-01T22:58:04+00:00 1 Answers 24 views 0

The correct solution is “3.6975 M“.

Explanation:

The given values are:

Volume of solution,

V = 23.2 mL

Density,

D = 1.42 g/mL

Final volume,

= 200 mL

or,

= 0.2 L

Now,

The mass will be:

= $$D\times V$$

= $$1.42\times 23.1$$

= $$32.802 \ g$$

Mass of HNO₃ will be:

= $$\frac{32.802}{0.704}$$

= $$46.59375 \ g$$

Mol of HNO₃ will be:

= $$\frac{mass}{MW}$$

= $$\frac{46.59375}{63}$$

= $$0.7395 \ mol$$

hence,

The concentration will be:

= $$\frac{mol \ of \ HNO_3}{final \ V}$$

= $$\frac{0.7395}{0.2}$$

= $$3.6975 \ M$$