When 50 ~mL of 0.1 M NH ₃ is mixed with 10 ~mL of 0.1 M HCl then what is the pH of resultant solution? ( p K_b=4.75 )

Step-by-step solution

aligned & NH ₃+ HCl NH ₄ Cl & Initial 50 0.1 10 0.1 & =5 mmol =1 mmol & After 4 mmol 0 mmol 1 mmol & reaction & pOH = p K_b+ [ salt ] [ base ] & =4.75+ ( 1 4 )=4.15 & pH =14- pOH =14-4.15=9.85 & aligned