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CAIE IGCSE Chemistry 7.3.5 Term water of crystallisation as the

CAIE IGCSE Chemistry 7.3.5 Term water of crystallisation as the
Cambridge IGCSE Chemistry 0620 syllabus for exams in 2026, 2027 and 20282026–2028

Practise using water of crystallisation in hydrated salt formulae, colour changes and heating observations for common crystals.

How this is tested

  • define water of crystallisation as water molecules present in hydrated crystals
  • link heating hydrated salts to loss of water, colour change and anhydrous formulae

Question 2

[Maximum number: 4]

Cobalt and copper are transition elements.

Question 2(c)

(a)

Both copper and cobalt can form coloured compounds. Some of these compounds contain water of crystallisation.

[ 4 ]

Question 2(c)(i)

(i)

Define the term water of crystallisation.

[ 2 ]

Question 2(c)(ii)

(ii)

State the colour and formula of hydrated cobalt(II) chloride crystals.
colour
formula

[ 2 ]