Question

Below are some questions and their answers. I would appreciate it if someone could please explain to me step by step how to get these answers?

1) One buffering component of your blood is the phosphate system that maintains your blood pH at 7.4. The major species of the phosphate system at this pH are likely:a. H3PO4 and H2PO4– b. H2PO4– and HPO42– c. HPO42– and PO43– d. H3PO4, H2PO4– and HPO42– e. H3PO4 only
answer: H2PO4– and HPO42–

2)Which solution is most acidic (has the lowest pH)? a. 0.15M HClO4 b. 0.30M hydrofluoric acid (remember HF is a weak acid) c. 1.5M potassium nitrite d. 1.5M sodium dihydrogen phosphate (NaH2PO4)
answer: 0.15M HClO4

3) The conjugate base of HC2O4− is_________. answer: C2O42−

4) Which of the following will not produce a buffered solution? a. 100 mL of 0.1 M Na2CO3 and 50 mL of 0.1 M HCl b. 100 mL of 0.1 M NaHCO3 and 25 mL of 0.2 M HCl c. 100 mL of 0.1 M Na2CO3 and 75 mL of 0.2 M HCl d. 50 mL of 0.2 M Na2CO3 and 5 mL of 1.0 M HCl e. 100 mL of 0.1 M Na2CO3 and 50 mL of 0.1 M NaOH
Answer: e. 100 mL of 0.1 M Na2CO3 and 50 mL of 0.1 M NaOH

5) Which solution has a greater pH 0.25 M NaHSO3 or 0.38 M NaHSO3? a. 0.25 M NaHSO3 b. 0.38 M NaHSO3 c. the pH of both solutions are the same because sodium bisulfite is a salt and salts are neutral d. the pH of both solutions are the same because bisulfite is amphoteric and amphoteric salts are neutral e. the pH of both solutions are the same because bisulfite is amphoteric and the pH only depends upon the pKa values
answer: e. the pH of both solutions are the same because bisulfite is amphoteric and the pH only depends upon the pKa values