Question

3.65g of Hcl is dissolved in 1 L of its solution . Express the concentration of Hcl in molarity .( molar mass of Hcl is 36.5g mol-1).​

Answer 1

Given:-

→ Mass of HCl = 3.65g

→ Molar mass of HCl = 36.5 g mol⁻¹

→ Volume of solution = 1 L

To find:-

→ Concentration of HCl in molarity

[ Molarity of the solution ]

Solution:-

We can clearly see that HCl is the solute here.

Number of mole in 3.65g of HCl :-

= Given Mass/Molar mass

= 3.65/36.5

= 0.1 mole

Molarity of a solution :-

= Mole of solute/Liters of solution

= 0.1/1

= 0.1 M

Thus, concentration of HCl in molarity is 0.1 M .

Some Extra Information:-

• Molarity is defined as the number of

moles of solute present in 1000 mL or

1 L of the solution

• The units of molarity are mol L⁻¹ (M)

and mol dm⁻³

Answer 2

Mass of HCl = 3.65 g

Molar mass of HCl = 36.5 g

$\therefore$ Number of moles = 3.65 g ÷ 36.5 g = 0.1 mole

Volume of solution = 1 L

We know,

Molarity = (Number of moles of solute) ÷ (Volume of solvent in L)

$\therefore$ Molarity = (0.1 mol)/(1 L)

$\leadsto$ 0.1 mol L^-1

$\leadsto$ 0.1 M (Solution)