Question

1) A solution was prepared by dissolving 25g of sugar in 100g of water. Calculate the mass percentage of solute.
2) 16 grams of NaOH is dissolved in 100 grams of water at 25 degree to form saturayed solution. Find the mass percentage of solute and solvent

Answer 1

Answer:

Given mass of NaOH=16 grams → Solute.

Given mass of water = 100 grams → Solvent

Solubility (in g/100g) =

solvent

Mass

×100

=

100

16

×100=16

Solubility of the solution is 16(g/100g)

Weight Percentage =

massofsolution

MassofSolute

×100

(100+16)g

16g

×100

Weight percentage =13.79%

Answer 2

1. Given :

$\text{Mass of solute = 25g}$

$\text{Mass of solvent = 100g}$

To Find :

$\text{Mass percentage of Solute}$

Solution :

$\text{Mass percentage = }\frac{\text{Mass of the solute}}{\text{Mass of solution}} \times 100$

$\text{Mass percentage = }\frac{\text{Mass of solute}}{\text{Mass of solute}+\text{mass of solvent}}$

$\implies \frac{25}{25 + 100} \times 100$

$\implies \frac{25}{125} \times 100$

$\implies \frac{1}{5} \times 100 \implies \frac{100}{5}$

$\boxed{\text{Mass percentage of solute = }20}$

2. Given :

$\text{Mass of the solute NaOH = 16g}$

$\text{Mass of the Solvent H _2 O = 100g}$

To Find :

$\text{(I) Mass percentage of solute}$

$\text{(II) Mass percentage of solvent }$

Solution :

$\text{(I) Mass percentage of solute}$

$\text{Mass percentage of solute = }\frac{\text{Mass of the solute}}{\text{Mass of solution}} \times 100$

$\text{Mass percentage of solute = }\frac{\text{Mass of solute}}{\text{Mass of solute}+\text{mass of solvent}}\times 100$

$\implies \frac{16 \times 100}{16 + 100}$

$\implies \frac{1600}{116}$

$\boxed{\text{Mass percentage of solute = 13.79}}$

$\text{(II)Mass percentage of solvent }$

$\text{Mass percentage of solvent = }100 - \text{mass percentage os solute}$

$\implies 100 - 13.79$

$\boxed{\text{Mass percentage of solvent = 86.21}}$