Question

answer with solution​

Answer 1

Answer:

pH of buffer is 10.43.

Explanation:

Hydrochloric acid reacts with sodium carbonate to neutralise the base as follows :

Na2CO3+HCl⟶NaCl+H2CO3

Moles of Na2CO3=Mm=10530=0.28 mol

Moles of HCl=V(L)×M=(0.15)×1=0.15 mol

Moles of Na2CO3=0.28−0.15=0.13 mol

Concentration of Na2CO3=(0.500+0.15)0.13M

Concentration of salt =(0.5+0.15)0.15M

pH of buffer =pKa+[Base]log[Salt]

⇒pKa=−log[Ka]=−log[5.63×10−11]==10.43

Thus, pH of buffer is 10.43.