The molecular mass of sulphuric acid is 98. If 49 g of the acid is dissolved in water to make one litre of solution, what will be the strength of the acid?
Two normal
One normal
0·5 normal
Four normal
Answer is Wrong!
Answer is Right!
This question was previously asked in
UPSC CDS-1 – 2017
Number of moles of H₂SO₄ = Mass / Molar mass = 49 g / 98 g/mol = 0.5 mol.
The molarity of the solution is Moles / Volume (L) = 0.5 mol / 1 L = 0.5 M.
Normality (N) is defined as Molarity (M) multiplied by the n-factor (equivalents per mole). For sulfuric acid acting as an acid, it has two acidic protons (H⁺) that can be donated, so its n-factor is 2.
Normality = Molarity × n-factor = 0.5 M × 2 = 1 N.
The strength of the acid solution is one normal.