Question

Use the equation showing the dissociation of iron thiocyanate in water to answer the question.

FeSCN^2+(aq) ⇄ Fe^3+(aq) + SCN–Negative ion(aq)

In solution, FeSCN^2+ ions are red, Fe^3+ ions are pale yellow, and SCN–Negative ion ions are colorless.

Given that iron ions bind with hydroxide ions to produce solid Fe(OH)3, which statement about the solution is correct?

(1 point)
Responses

Decreasing the pH will release Fe^3+ ions and cause the solution to become more red.
Decreasing the pH will release Fe^ 3+ ions and cause the solution to become more red.

Increasing the pH will remove Fe^3+ ions and cause the solution to become more red.
Increasing the pH will remove Fe ^3+ ions and cause the solution to become more red.

Increasing the pH will release Fe^3+ ions and cause the solution to become more yellow.
Increasing the pH will release Fe^ 3+ ions and cause the solution to become more yellow.

Decreasing the pH will remove Fe^3+ ions and cause the solution to become more yellow.
Decreasing the pH will remove Fe ^3+ ions and cause the solution to become more yellow.
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Answer 1

Decreasing the pH will release Fe^3+ ions and cause the solution to become more red.

Reason: Lowering pH (adding H+) dissolves Fe(OH)3(s), releasing Fe^3+. The added Fe^3+ shifts FeSCN^2+ ⇄ Fe^3+ + SCN– to the left (Le Chatelier), forming more red FeSCN^2+ and intensifying the red color.