Question

The weight of solute present in 200 mL of 0.1 M $H_{2}S{O}_4$ is:

• A. $2.45g$
• B. $4.9g$
• C. $1.96g$
• D. $3.92g$

Answer 1

Answer: (C)

$1.96g$

Molarity is a measure of the concentration of a solute in a solution or of any chemical species, in terms of the amount of a substance in a given volume.

Molar concentration or molarity is most commonly expressed in units of moles of solute per litre of solution. it is represented by lowercase c:

$c=\frac{n}{V}$

where,

$n$= no. of moles of solute.

$V$= volume of solution in liters.

Calculation:

Let the weight of solute be $x$ g.

Number of moles required be $\frac{x}{98.07}$

Molarity $c=0.1M$

The volume of solution in litres is $V=\frac{200}{1000}=0.2$ litres

Molarity of solution can be calculated as $c=\frac{\frac{x}{98.07}}{0.2}=0.1⟹x=98.07\times 0.1\times 0.2⟹x=1.961$ g

Weight of sulphuric acid is $1.96$ g.