A Level Chemistry OCR Practice Exam

Disable ads (and more) with a membership for a one time $2.99 payment

Prepare effectively for the A Level Chemistry OCR Exam with our valuable resources, including multiple choice questions and hints. Unlock your potential and ace your exam with comprehensive practice materials designed for your success!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.

Which of the following is an example of a compound that contains water of crystallisation?

NaCl
CuSO4·5H2O
C6H12O6
C2H5OH

The correct answer is: CuSO4·5H2O

The compound that contains water of crystallisation is CuSO4·5H2O. This notation indicates that for every molecule of copper(II) sulfate (CuSO4), there are five molecules of water (H2O) integrated into its crystalline structure. This incorporation of water molecules into the crystal lattice is called water of crystallisation, and it plays a significant role in the physical properties of the compound, such as its color and solubility. In contrast, sodium chloride (NaCl) is an inorganic ionic compound that does not include water in its crystalline structure, rather forming a simple ionic lattice. Glucose (C6H12O6) is a simple sugar that does not contain any water of crystallisation; it exists as a solid but does not have water molecules integrated into its structure. Ethanol (C2H5OH), being an alcohol, is a liquid and does not crystallize with water as part of its structure. Therefore, CuSO4·5H2O is the only compound among the options that explicitly includes water of crystallisation in its formula.