Question

some chemical compounds are listed in the first column of the table below. each compound is soluble in water.
imagine that a few tenths of a mole of each compound is dissolved in a liter of water. the important chemical species that would be present in this solution are written in the second column of the table. use the checkboxes to classify each compound.
compound important species present when dissolved in water type of compound (check all that apply)
ionic molecular strong acid weak acid strong base weak base
hc₂h₃o₂ h₃o⁺, c₂h₃o₂⁻, hc₂h₃o₂, h₂o
nabr na⁺, br⁻, h₂o
nh₃ nh₄⁺, oh⁻, nh₃, h₂o
koh k⁺, oh⁻, h₂o

Explanation:

• For \(HC_2H_3O_2\):
• It is a molecular compound (not composed of ions in the pure state).
• It is a weak acid as it partially dissociates in water (\(HC_2H_3O_2

ightleftharpoons H_3O^{+}+C_2H_3O_2^{-}\)) to produce \(H_3O^{+}\) ions along with undissociated \(HC_2H_3O_2\) molecules.

• For \(NaBr\):
• It is an ionic compound (composed of \(Na^{+}\) and \(Br^{-}\) ions). When dissolved in water, it completely dissociates (\(NaBr = Na^{+}+Br^{-}\)) and is neither an acid nor a base.
• For \(NH_3\):
• It is a molecular compound.
• It is a weak base as it partially reacts with water (\(NH_3 + H_2O

ightleftharpoons NH_4^{+}+OH^{-}\)) to produce \(OH^{-}\) ions along with undissociated \(NH_3\) molecules.

• For \(KOH\):
• It is an ionic compound (composed of \(K^{+}\) and \(OH^{-}\) ions). When dissolved in water, it completely dissociates (\(KOH=K^{+}+OH^{-}\)) and is a strong base.

Answer:

• \(HC_2H_3O_2\): molecular, weak acid
• \(NaBr\): ionic
• \(NH_3\): molecular, weak base
• \(KOH\): ionic, strong base