Answer
i. d. Magnesium sulfate
ii. b. Sodium chloride
iii. c. Potassium carbonate
iv. a. Barium nitrate
Picture ii.
None of these pictures are a good representation of $HC_2H_3O_2$ because $HC_2H_3O_2$ is a weak acid.
Work Step by Step
i. Magnesium has an ionic charge of 2+ and sulfate has an ionic charge of 2-. Therefore, magnesium sulfate best fits picture i.
ii. Sodium has an ionic charge of 1+ and chloride has an ionic charge of 1-. Therefore, sodium chloride best fits picture ii.
iii. Potassium has an ionic charge of 1+ and carbonate has an ionic charge of 2-. Therefore, potassium carbonate best fits picture iii.
iv. Barium has an ionic charge of 2+ and nitrate has an ionic charge of 1-. Therefore barium nitrate best fits picture iv.
Picture ii. best fits $HNO_3$ as H has an ionic charge of +1 and $NO_3$ has an ionic charge of 1-.
None of these pictures are a good representation of $HC_2H_3O_2$ because $HC_2H_3O_2$ is a weak acid which only partially dissociates into its ions. Therefore, a correct image would have few ions and mostly compounds. However, each of the pictures only depict ions in solution.
