Describe and explain how the density and melting point of cobalt compare to those of calcium. density of cobalt explanation melting point of cobalt explanation

1. (a)Describe and explain how the density and melting point of cobalt compare to those of calcium. density of cobalt explanation melting point of cobalt explanation[3]
2. (b)Transition metals can form complexes. What is meant by the term transition metal complex?[1]
3. (c)(i)Cobalt can form the compounds [Co(NH₃)₅Br]SO₄ and [Co(NH₃)₅SO₄]Br. These two compounds are structural isomers. Define the term structural isomer.[1]
4. (c)(ii)Draw a three-dimensional diagram to show the structure of the ion [Co(NH₃)₅Br]²⁺. Name its shape.[1]
5. (c)(iii)State the type of bonding between the cobalt ion and NH₃ groups in the [Co(NH₃)₅Br]²⁺ ion.[1]
6. (c)(iv)State the oxidation number of cobalt in • [Co(NH₃)₅Br]²⁺ oxidation number of Co = .............................. • [Co(NH₃)₅SO₄]⁺ oxidation number of Co = ..............................[1]
7. (d)Solutions of the compounds [Co(NH₃)₅Br]SO₄ and [Co(NH₃)₅SO₄]Br can be distinguished from each other by simple chemical tests. Assume that any species bonded to the cobalt ion does not react in these tests. Complete the table with two different tests that could be used to positively identify each compound. Give the expected observation with each compound.[2]
8. (e)The two compounds [Co(NH₃)₅Br]SO₄ and [Co(NH₃)₅SO₄]Br are different colours. Explain why the colours of the two compounds are different.[2]
9. (f)Some transition metals and their compounds act as catalysts. The catalysis can be classified as heterogeneous or homogeneous. Complete the table by placing one tick (✓) in each row to indicate the type of catalysis in each reaction.[2]

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