Question

Density of a solution containing 14% by mass of
sulphuric acid is 1.05 gm/mL. What is the molarity
of solution?
(A) 0.5 M
(B). 1.0M
(C) 1.5 M
(D) 2.0 M
athualcohol in aqueous ethyl
​

Answer 1

Answer ⇒ 1.499 M.

Explanation ⇒ Density of the solution = 1.05 g/mL.

Let the mass of the solution be 100 gm. Thus, mass of sulphuric acid in solution = 14 gm.

∴ Volume of solution = mass of solution/density

∴ Volume of solution = 100/1.05

∴ Volume of solution = 95.24 mL.

Moles of Sulphuric acid = Mass of acid/Molecular mass.

∴ Moles = 14/98

∴ Moles = 0.143 moles.

Now, using the formula of molarity,

Molarity = (No of moles of solute/Volume of sol in ml.) × 1000

∴ Molarity = 0.143/95.24 × 1000

∴ Molarity = 1.499 M.

Hence, the molarity of the solution is 1.499 M.

Hope it helps.

Answer 2

Tiwaavi sir, is already given a complete details explanation to get result. here i want to show you an easy formula.

Let's discuss about that.

if density of solution is d g/mL

percentage mass composition of solute in solution is x %

and molar mass of solute is M

then, molarity = x × d × 10/M

here, solute is sulphuric acid so, molar mass , M = 98 g/mol.

percentage mass composition of sulphuric acid , x = 14%

and density of solution is d = 1.05g/mL

now, molarity = (14 × 1.05 × 10)/98

= (14 × 10.5)/98

= 10.5/7

= 1.5 M

hence, option (C) is correct choice