18. What is the pH at the equivalence point when 100.0 mL of 0.1 M HC7H5O2 (Ka = 6.4 × 10-5 ) titrated by 0.10 M NaOH?(A)4.19(B) 10.74(C)5.96(D) 7.89 (E)8.45

16. Consider the following solutions: 0.010 m Na3PO4 in water; 0.020 m CaBr2 in water; 0.020 m KCl; 0.020 m HF in water (HF is a weak acid). Assuming complete dissociation of the soluble salts, which salt dissolved in water would have the highest vapor pressure at 28℃? (A) 0.010 m Na3PO4(B) 0.020 m CaBr2(C)0.020 m KCl(D) 0.020 m HF (E)They all have the same vapor pressure

18. What is the pH at the equivalence point when 100.0 mL of 0.1 M HC₇H₅O₂(K_a= 6.4 × 10^-5 ) titrated by 0.10 M NaOH?
(A)4.19
(B) 10.74
(C)5.96
(D) 7.89
(E)8.45

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