20 ml of M/10 NH4OH solution is mixed with 16ml of M/10 HCL solution.The pH of the resulting solution is (pKb of NH4OH = 4.74)

Question

a)9.26

b)6.85

c)4.74

d) 8.66

Answer 1

The correct option is (D) 8.66

Milliequivalent of NH₄OH = 20 x 1/10  = 2
Milliequivalent of HCl: 16 x 1/10 = 1.6

Now,

= 4.74 + log(1.6/0.4) = 4.74 + log (4) = 4.74 + 0.602 = 5. 342

P^H = 14 - 5.342 = 8.66

Comments

the answer should be from the given options. Please recheck your solution and give the appropriate solution.

---

Now it is clear. A subtraction was left undone.