Waec Model Questions Vol1 2021 Chemistry Question 5

Practice essay / theory question 5 from the 2021 Waec Model Questions Vol1 Chemistry examination. This question covers Stoichiometry, Limiting reagent, Percent yield .

Waec Model Questions Vol1 2021 Chemistry Essay / Theory
Topics: Stoichiometry Limiting reagent Percent yield
Question 5 WAEC_MODEL_QUESTIONS_VOL1 • 2021 • CHEMISTRY • essay

A laboratory experiment involves the reaction 2 Al(s) + 3 CuSO₄(aq) → Al₂(SO₄)₃(aq) + 3 Cu(s) A student weighs 15.0 g of aluminium metal and 30.0 g of copper(II) sulphate pentahydrate (CuSO₄·5H₂O). The molar masses are: Al = 26.98 g mol⁻¹, CuSO₄·5H₂O = 249.7 g mol⁻¹, Al₂(SO₄)₃ = 342.2 g mol⁻¹, Cu = 63.55 g mol⁻¹. After the reaction is complete, the student isolates and weighs 24.5 g of copper metal. Answer the following questions:

Question Parts

( a )
Identify the limiting reagent and calculate the theoretical mass of copper that could be produced.
( b )
Calculate the percent yield of copper obtained in the experiment.
( c )
The copper(II) sulphate used was impure; it contained 5 % by mass of an inert solid that does not react. Discuss qualitatively how this impurity would affect the percent yield calculated in part (b).

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About This Question

This is Waec Model Questions Vol1 2021 Chemistry Question 5. It is one of the essay questions from the 2021 Waec Model Questions Vol1 Chemistry examination.

The question covers Stoichiometry, Limiting reagent, Percent yield .

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