Question

A solution is prepared by dissolving 20 g NaOH (FW = 400 g/mol) to 255 ml of solution. If the density of the solution is 1.15 gim, what is the mass percent NaOH in the solution? 0.68% 0.78% 0.90% 6.8% 78% nt Navigator

Answer 1

6.82% is the mass percent NaOH in the solution.

Step-by-step explanation:

Mass of the solute that is NaOH = m = 20 g

Mass of the solution = M

Volume of the solution = V = 255 mL

Density of the solution = d = 1.15 g/mL

`Density=(Mass)/(Volume)`

`1.15 g/mL=(M)/(255 mL)`

M = 293.25 g

Mass percentage of solute :(w/w)%

`(m)/(M)* 100`

`(w/w)\%=(20 g)/(293.25 g)* 100=6.82\%`

6.82% is the mass percent NaOH in the solution.