Question

36 g of HCI dissolves in 100 g of solution. The density of HCI is 1.19 gcm.
The molar mass of the HCl solution will be:
A) 36.5 g/mol
C) 38.0 g/mol
B) 100 g/mol
D) 11.73 g/mol​

Answer 1

the molar mass of the HCL is 11.73 h/mol

Answer 2

The molar mass of HCl solution will be 36.5 g/mol

It has given that, 36g of HCl dissolves in 100g of solution, the density of HCl is 1.19 g/cm³.

we have to find the molar mass of the HCl solution.

solution :let molecular mass of HCl = M

given mass of HCl = 36g = mass of solute

mass of solution = 100g

density of solution = 1.19 g/cm³

so volume of solution = mass/density = 100/1.19 ≈ 84 cm³

molarity = no of moles of solute/volume of solution in Litre

= (36/M)/(84/1000)

= 36000/84M

here you forgot to write molarity of solution.

given, molarity = 11.74 molar

so, M = 360000/84 × 11.74 ≈ 36.5

therefore the molar mass of HCl is 36.5 g/mol

let's try to solve another method,

% percentage by weight of solute , % w/W = 36/100 × 100 = 36 %

density of solution, d = 1.19

molar mass of HCl = M

molarity of solution = 11.74 molar

we know, molarity = (% w/W × 10 × d)/M