Question 5

QUESTION 5 (Start on a new page.)

Consider the compound Aℓ₂ (SO₄)₃ .

5.1 Write down the NAME of the compound above. (1)

5.2 Define the term molar mass. (2)

5.3 Calculate the following for Aℓ₂ (SO₄ )₃ :
5.3.1 Its molar mass (2)
5.3.2 Its percentage composition (3)
5.3.3 The number of moles present in 85,5 g (3)
5.3.4 The number of aluminium atoms present in 85,5 g (3)

5.4 Particles of Aℓ ₂ (SO ₄ ) ₃ are bonded in a crystal lattice.

Write down the following for this crystal lattice:

5.4.1 The name

5.4.2 The particles of which it consists

5.4.3 TWO physical properties (2)

5.5 500 g of Aℓ₂(SO₄)₃ is dissolved in 2 dm³ water.

5.5.1 Define the term concentration. (2)

5.5.2 Calculate the concentration of the solution. (4)

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