0.1 mol of a basic substance(x) requires 25cm3 of 8.0 mol/dm3 hydrochloric acid for complete neutralisatin.x could be

1.Al(OH)3

2.CuO

3.K2O

4.NaOH

 

options:

a.1 and 2

b.2 and 3

c.1 and 4

d.2 and 4

The correct option is b. 2 and 3

The total moles of H⁺ ions can be found out as 0.025 dm³ x 0.8 mol/dm³ = 0.2 moles of H⁺ ions of HCl

0.2 moles of H⁺ ions can be neutralised by 0.1 mol of CuO or 0.1 mol of K₂O as 1 mol of CuO or 1 mol of K₂O require 2 mol of HCl for complete neutralisation.

CuO + 2HCl → CuCl₂ + H₂O

K₂O + 2HCl → 2KCl + H₂O

 

While in case of 0.1 mol of NaOH and 0.1mol of Al(OH)₃, 0.1 mole and 0.3 moles of HCl is required respectively for complete neutralisation.