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.

Answer 1

The correct solution is "3.6975 M".

Step-by-step 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* V`

=
`1.42* 23.1`

=
`32.802 \ g`

Mass of HNO₃ will be:

=
`(32.802)/(0.704)`

=
`46.59375 \ g`

Mol of HNO₃ will be:

=
`(mass)/(MW)`

=
`(46.59375)/(63)`

=
`0.7395 \ mol`

hence,

The concentration will be:

=
`(mol \ of \ HNO_3)/(final \ V)`

=
`(0.7395)/(0.2)`

=
`3.6975 \ M`