Question

a solution is prepared by mixing 20g of sodium chloride in 80g of water what are the concentrations of the solute and solvent in % by mass

Answer 1

Answer:

B

Explanation:

I think this is the best answer.

Answer 2

The concentrations of the solute and solvent in % by mass is 20% and 80% respectively.

Given:

A solution is prepared by mixing 20g of sodium chloride in 80g of water.

To find:

The concentrations of the solute and solvent in % by mass.

Solution:

To solve this question, first of all, we should know that the concentration of solute in percentage by mass is

$= \frac{mass \: of \: solute \: (in \: g)}{mass \: of \: solution \: (in \: g)} \times 100$

Similarly,

the concentration of solvent in percentage by mass is

$= \frac{mass \: of \: solvent \: (in \: g)}{mass \: of \: solution \: (in \: g)} \times 100$

$or \: \: \% \: \: by \: mass \: of \: solution\: - \% \: by \: mass \: of \: solute$

Now, as given, we have,

Mass of sodium chloride or solute = 20g

Mass of water or solvent = 80g

So,

Mass of solution = solute + solvent = 20g + 80g = 100g

Thus,

the concentration of sodium chloride in percentage by mass is

$= \frac{20}{100} \times 100$

$= 20\%$

Similarly,

the concentration of water in percentage by mass is

$= \frac{80}{100} \times 100$

$= 80\%$

Or

$= 100\% - 20\%$

$= 80\%$