Question

16. A solution is made by dissolving 25 g of NaCl in enough water to make 1.0 L of solution. Assume the density of the solution is 1.0 g/cm3. Calculate the molarity and molality of the solution.

Answer 1

The molarity will be "0.43 M" and molality will be "0.43 m".

Step-by-step explanation:

Given that:

mass of NaCl,

= 25 g

Volume of solution,

= 1 L

Density of solution,

= 1 gm/cm³

Now,

The weight of solvent will be:

=
`Volume* density`

=
`1* 1`

=
`1 \ kg`

The mole of NaCl will be:

=
`(mass)/(Molar \ mass)`

=
`(25)/(58.44)`

=
`0.43`

hence,

The molarity will be:

=
`(number \ of \ mole)/(Volume \ of \ solution)`

=
`(0.43)/(1)`

=
`0.43 \ M`

The molality will be:

=
`(mole \ of \ solute)/(Weight \ of \ solvent)`

=
`(0.43)/(1)`

=
`0.43 \ m`