Question

If 32.5 grams of CaO are dissolved in 212 grams of water, what is the concentration of the solution in percent by mass?

6.52% CaO

8.67% CaO

13.3% CaO

15.3% CaO

Answer 1

percent by mass of CaO= Mass of solute/ moles of solution x 100%

(32.5g)/ (32.5g+212g) x 100%
= 13.29 and when you round it becomes 13.3% CaO

Answer 2

Concentration of solution in percent by mass is 13.3% CaO

Step-by-step explanation:

% by mass =
`(mass of solute)/(mass of solution)* 100`

Here solute is CaO and solvent is water.

So, mass of solution = (mass of solute)+(mass of solvent)

= (mass of CaO)+(mass of water)

= 32.5 g + 212 g

= 244.5 g

So, Concentration of solution by percent mass =
`(mass of CaO)/(mass of solution)* 100` =
`(32.5)/(244.5)* 100` = 13.3 %