Question

What will be the resultant ph when 200ml of an aqueous solution of hcl(ph=2.0)is mixed with 300 ml of solution of naoh (ph=13)?

Answer 1

From 200ml hcl

[H+]=200ml × 10^(-2)=2M

From 300ml naoh

[H+]=300ml × 10^(-13)=3 × 10^(-11)M

total H+ = 2M + 3× 10^(-11)M=2M

total volume=200+300=500ml

average H+=2/500=4× 10^(-3)

now taking negative logarithm that is

pH=2.398