Two different solution A and B of a dibasic acid are prepared. 480 ml of 1.5M solution A is mixed with 520 mL of 1.2M solution B. The normality of the final solution is

The quantities provided in the question are:

M₁ = 1.5 M     V₁ = 480 ml

M₂= 1.2 M     V₂ = 520 ml

V_final=480 + 520 = 1000 ml

The product of total mass and volume can be expressed as:

M_finalV_final=M₁V₁+M₂V₂

${\mathrm{M}}_{\mathrm{final}}\left(1000\right)=1.5\times 480+1.2\times 520$

${\mathrm{M}}_{\mathrm{final}}=1.344 \mathrm{M}$

No. of hydrogen ions = 2 (dibasic acid)

${\mathrm{N}}_{\mathrm{final}}={\mathrm{M}}_{\mathrm{final}}\times \mathrm{no}. \mathrm{of} \mathrm{hydrogen} \mathrm{ions}$

${\mathrm{N}}_{\mathrm{final}}=1.344\times 2=2.68 \mathrm{N}$

Therefore the correct option is D) 2.68 N.