JEE Advanced Model Paper 10 with solutions for online practice

Answer (A)
H2O → H+ + OH− (donates H+ , Bronsted acid)
H2O + H+ → H3O+ (Bronsted base, accept H+)
H2O : + H+ → [H2O:→H]+ (Lewis base)
Water at 60°C must have pH less than 7. So asample shows pH = 7, so it must be basic in natureand turns red litmus blue
N1V1 = N2V2
0.1 V = N2 (100 V)
N2 = 10−3
pH = 3
So pH changes by 2 units, (not changes to 2 unit)