Skip to content

Course home

Sign up

Transition metals (A-level only)

EasyMediumHard
12345678910111213141516171819202122232425262728293031323334
Question 22

The ligand substitution reaction between hexaaquachromium(III) ions and ethanedioate (oxalate) ions can be represented by the following equation:

[Cr(H2O)6]3+(aq)+3C2O42−(aq)→[Cr(C2O4)3]3−(aq)+6H2O(l) [\text{Cr}(\text{H}_2\text{O})_6]^{3+}(aq) + 3\text{C}_2\text{O}_4^{2-}(aq) \rightarrow [\text{Cr}(\text{C}_2\text{O}_4)_3]^{3-}(aq) + 6\text{H}_2\text{O}(l) [Cr(H2​O)6​]3+(aq)+3C2​O42−​(aq)→[Cr(C2​O4​)3​]3−(aq)+6H2​O(l)

Which statement is correct about this reaction?

A

The coordination number of the chromium ion decreases.

B

The reaction is driven by a highly negative enthalpy change.

C

The entropy change of the reaction is large and positive.

D

The shape of the chromium complex changes from octahedral to tetrahedral.

Markscheme

Transition metals (A-level only) Questions

  1. A Level
  2. /Chemistry
  3. /Transition metals (A-level only)

63 exam-style questions on AQA A Level Chemistry Transition metals (A-level only), covering General properties of transition metals (A-level only), Substitution reactions (A-level only), Shapes of complex ions (A-level only), Formation of coloured ions (A-level only), Variable oxidation states (A-level only), and Catalysts (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.

Question bank