A buffer at pH 7.45 is prepared by mixing solutions of KH2PO4 and K2HPO4. Which of...

Question

Question

A buffer at pH 7.45 is prepared by mixing solutions of KH2PO4 and K2HPO4. Which of the following ratios of [base]/[acid] is required?

For phosphoric acid, Ka1 = 7.5 × 10-3 Ka2 = 6.2 × 10-8 Ka3 = 4.2 × 10-13

[base]/[acid] = 1.75

[base]/[acid] = 1.24

[base]/[acid] = 0.57

[base]/[acid] = 1.27

[base]/[acid] = 0.79

Answer 1

Answer #1

-8. H₂ PO 4 ~ H + H₂PO4 , Kaya 7.5410 to pka, = 2.2 H₂ pou H² + HPOL , Kaz= 6:24 100 pkaz= 7.2 Here the buffer is made of KHP

Answer 2

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