The Basic buffer solution is made with 0.1 M NH ₄ OH and 0.2 M NH ₄ Cl . If K_b for the base is 1.8 10⁻⁵ , what is the pH of the buffer?

Step-by-step solution

Given: [ NH ₄ OH ] = 0.1 M [ NH ₄ Cl ] = 0.2 M K_b = 1.8 10⁻⁵ First, calculate p K_b : p K_b = - (1.8 10⁻⁵) = 5 - (1.8) = 4.74 Using the Henderson-Hasselbalch equation for a basic buffer: pOH = p K_b + ( [ Salt ] [ Base ] ) Substituting the given values: pOH = 4.74 + ( 0.2 0.1 ) pOH = 4.74 + 2 pOH = 4.74 + 0.30 = 5.04 Now, calculate the pH: pH = 14 - pOH pH = 14 - 5.04 = 8.96 Answer: 8.96