Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter

Chemical Formulae, Equations and Calculations Part 1

19 practice questions

Start practising (8 questions)

Practice questions

1–8 of 8 · Normal

Question 1
2 marks · Normal
Write the balanced chemical equation, including state symbols, for the reaction between sodium hydroxide solution and hydrochloric acid when they form sodium chloride solution and water.
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Question 2
4 marks · Normal
Answer the questions about the compound sodium sulfate, Na2SO4.
(a)
State the relative atomic masses (Ar) of sodium (Na), sulfur (S), and oxygen (O).
[1 mark]
(b)
Calculate the relative formula mass (Mr) of sodium sulfate, Na2SO4.
[2 marks]
(c)
State the Mr of Na2SO4 to 1 decimal place.
[1 mark]
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Question 3
3 marks · Normal
A student has 21 g of magnesium chloride (MgCl2). Calculate the number of moles of MgCl2 present.
(Ar: Mg = 24, Cl = 35.5)
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Question 4
3 marks · Normal
The equation for a reaction is:
A student reacts 27.0 g of aluminium (Al) with 85.0 g of chlorine (Cl2). Using the information in the equation, explain how you would determine which reactant is in excess and calculate the maximum mass of aluminium chloride (AlCl3) that could be formed.
(Ar: Al = 27, Cl = 35.5)
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Question 5
4 marks · Normal
A compound contains 9.45 g potassium, 5.25 g phosphorus, and 12.80 g oxygen.
(Ar: K = 39, P = 31, O = 16)
(a)
Calculate the number of moles of each element present in the sample.
[2 marks]
(b)
Determine the empirical formula of the compound.
[2 marks]
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Question 6
1 mark · Normal
Which of the following could be a method for determining the empirical formula of a metal oxide?
1. A.Burning the metal in air and weighing the increase in mass
2. B.Measuring the temperature before and after mixing with water
3. C.Electrolysing the metal and collecting the gas
4. D.Testing the metal with universal indicator
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Question 7
2 marks · Normal
Write the balanced chemical equation, with state symbols, for the reaction of calcium carbonate with dilute nitric acid to form calcium nitrate, carbon dioxide, and water.
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Question 8
4 marks · Normal
Answer the questions about calcium hydroxide, Ca(OH)2.
(a)
State the relative atomic masses (Ar) for Ca, O, and H.
[1 mark]
(b)
Calculate the relative formula mass (Mr) of Ca(OH)2.
[2 marks]
(c)
What mass of Ca(OH)2 is present in 0.5 mol of the compound?
[1 mark]
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