Answer:
pH = 9.70
Step-by-step explanation:
It is possible to answer this question using Henderson-Hasselbalch formula:
pH = pka + log [Base] /[Acid]
Base is NH₃ and acid NH₄⁺
Molarity of the compounds is:
NH₃: 0.850mol / 2.00L = 0.425M
NH₄⁺: 0.300mol / 2.00L = 0.150M
To find pka:
Ka×Kb = Kw
Ka = 1x10⁻¹⁴ / 1.77x10⁻⁵ = 5.65x10⁻¹⁰
pKa = -logKa = 9.25
Replacing:
pH = 9.25 + log [0.425] /[0.150]
pH = 9.70
I hope it helps!