Question
Question: 50 mL of 0.1 M NaOH is added to 60 mL of 0.15 M H3PO4 solution (K1, K2 and K3 for H3PO4 are 10–3, 10...
50 mL of 0.1 M NaOH is added to 60 mL of 0.15 M H3PO4 solution (K1, K2 and K3 for H3PO4 are 10–3, 10–8 and 10–13 respectively). The pH of the mixture would be about (log 2 = 0.3)
A
3.1
B
5.5
C
4.1
D
6.5
Answer
3.1
Explanation
Solution
H3PO4 + NaOH ⟶NaH2PO4
9 5 0
4 0 5
pH = pKa + log 45= 3 + 0.1 = 3.1