Solveeit Logo

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 \longrightarrowNaH2PO4

9 5 0

4 0 5

pH = pKa + log 54\frac{5}{4}= 3 + 0.1 = 3.1