Waec Model Questions Vol1 2018 Chemistry Question 1

Practice practical question 1 from the 2018 Waec Model Questions Vol1 Chemistry examination. This question covers Atomic Structure, Molar Mass Determination .

Waec Model Questions Vol1 2018 Chemistry Practical
Topics: Atomic Structure Molar Mass Determination
Question 1 WAEC_MODEL_QUESTIONS_VOL1 • 2018 • CHEMISTRY • practical

A student carried out an experiment to determine the molar mass of magnesium using the reaction: Mg(s) + 2HCl(aq) → MgCl₂(aq) + H₂(g). The following data were recorded: - Mass of dry magnesium ribbon: 0.150 g - Volume of hydrogen gas collected over water: 156.0 mL - Temperature of the gas: 25 °C - Atmospheric pressure: 760 mmHg - Vapour pressure of water at 25 °C: 23.8 mmHg Using the ideal gas equation (R = 0.0821 L·atm·mol⁻¹·K⁻¹), answer the questions below.

Question Parts

( a )
Calculate the pressure of the dry hydrogen gas collected (in mmHg and in atm).
( b )
Determine the number of moles of hydrogen gas collected and from this calculate the experimental molar mass of magnesium.
( c )
State two possible sources of error that could affect the result obtained.

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About This Question

This is Waec Model Questions Vol1 2018 Chemistry Question 1. It is a practical question from the 2018 Waec Model Questions Vol1 Chemistry examination.

The question covers Atomic Structure, Molar Mass Determination .

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