Question

H2SO4 used in lead storage cell is 38% by mass and had a density of 1.30 g/cm3 . calculate molarity

Answer 1

Hey mate!! That's ur answer..

38% acid by mass means 38g acid in g solution.

Density =1.30g/ml

Volume of solution = Mass/Density

= 100/1.30

Molar mass of sulphuric acid = 2×1+32+16×4

= 98g/mol

Molarity = G.Mass ×1000/molar mass × volume of solution (ml)

= 38×1000×130/100×100

= 5.0 M

Hope it helps...!!

Answer 2

Given:

Density of solution $= 1.30 \frac{g}{c m^{3}}$

Mass of sulphuric acid = 38% of the solution

Now 38% acid in solution means 38g in 100g solution or 100ml of the solution.

Volume of the solution $=\frac{M a s s}{D e n s i t y}$

$=\frac{100}{1.30}=76.92 \mathrm{ml}$

Now, we calculate the molar mass of sulphuric acid

[The atomic number of H = 1, S = 32 and O = 16]

$\mathrm{H}_{2} \mathrm{SO}_{4}=(2 \times 1+1 \times 32+4 \times 16)$  

=98 gm

We can calculate the molarity using the formula

$=\frac{\text {Gram mass} \times 1000}{(\text {molar mass} \times \text {volume of the solution})}$

$=\frac{38 \times 1000}{98 \times 76.92}=5.04 M$