AP EAMCET201822 Apr 2018Evening ShiftChemistryIonic EquilibriumActual
The pH of a buffer solution formed by mixing 30 ~mL of 0.1 M NH ₄ OH and 30 ~mL of 1 M NH ₄ Cl solutions is 8.6. The p K_b of NH ₄ OH is
Options
- A5.4
- B4.4
- C5.6
- D4.2
Correct answer
B. 4.4
Step-by-step solution
Given: pH of mixture =8.6 Also, pH =14- pOH =14-8.6=5.4 and pOH = p K_b+ [ Salt ] [ Base ] Here, [ Salt ]= [ NH ₄ Cl ]=1 M [Base ]= [ NH ₄ OH ]=0.1 M array ll & pOH = p K_b+ 1 0.1 & 5.4= p K_b+ 10 5.4= p K_b+1 & p K_b=5.4-1=4.4 array