Question

name 1. Equal volumes of 0.10 M HCl and 0.16 M HNO, were mixed. What is the pH of the resulting word 2. Equal volumes of 0.10 M HCl and 0.22 M CH,COOH (K.-1.8 X 10') were mixed. What is the pH of the resulting solution? 3. Equal volumes of 0.10 M HCl and 0.1.6 X 10-MHCIO. were mixed. What is the pH of the resulting solution?

Answer 1

1. Ans :-

Let Volume of HCl solution = V liter

Given that, HCl and HNO₃ have equal volume

So,

Volume of HNO₃ solution = Volume of HCl solution = V liter

Total volume after mixing the two solutions = V_T = V + V = 2V liter

Because,

Normality = gram equivalents of solute/Volume of the solution in L

So,

Gram equivalent of HCl (E₁) = Normality x Volume of HCl solution

because, Normality = Molarity x Valency factor

So,

Gram equivalent of HCl (E₁) = Molarity x Valency factor of HCl x Volume of solution in L

= 0.10 x 1 x V

= 0.10 V

Similarly,

Gram equivalent of HNO₃ (E₂) = Normality x Volume of HNO₃ solution

because, Normality = Molarity x Valency factor

So,

Gram equivalent of HNO₃ (E₂) = Molarity x Valency factor of HNO₃ x Volume of solution in L

= 0.16 x 1 x V

= 0.16 V

Now,

Resultant Normality (N_R) = E₁ + E₂ / V_T

= 0.10 V + 0.16 V / 2 V

= 0.26 V / 2 V

= 0.13

So,

[H⁺] = 0.13 M

We know,

pH = - log [H⁺]

= - log 0.13 M

= - ( -0.886)

= 0.886

Hence, pH of the resulting solution = 0.886