Chemistry Form 4 | 2025
CHAPTER 3
Activity 3.12 : Empirical Formula Of Magnesium Oxide.
Aim
Materials 10 cm magnesium ribbon and sand paper
Apparatus Crucible with lid, tongs, Bunsen burner, tripod stand, pipeclay triangle and
electronic balance
Procedure
Apparatus
set up
(drawing)
Results Description Mass (g)
Crucible + lid
Crucible + lid + magnesium
ribbon
Crucible + lid + magnesium
oxide
Observation 1) Magnesium burns ……………………… to release ………………… and
……………………… is formed.
Inference 1) Magnesium is a ………………….. metal.
2) Magnesium reacts with ……………………. in the air to form
……………………………..
Interpreting Determine the empirical formula of magnesium oxide
data Element Mg O
The empirical formula of magnesium oxide is ………………………
Discussion 1) What is the purpose of rubbing the magnesium ribbon with a sandpaper before
Prepared by : Siti Zarith binti Abd Wahab
Chemistry Form 4 | 2025
using it?
…………………………………………………………………………………………….
2) Name the white fumes that are produced.
…………………………………………………………………………………………….
3) Why does the crucible lid need to be opened occasionally?
…………………………………………………………………………………………….
4) Why does the crucible need to be kept closed during the experiment?
…………………………………………………………………………………………….
5) What will happen if the white fumes are released into the environment?
…………………………………………………………………………………………….
6) How do you ensure that the reaction has completed?
…………………………………………………………………………………………….
…………………………………………………………………………………………….
7) Write the equation for the reaction that occurred.
…………………………………………………………………………………………….
8) Can this method be used to determine the empirical formula of oxide of lead?
Give your reason.
…………………………………………………………………………………………….
…………………………………………………………………………………………….
9) Can this method be used to determine the empirical formula of zinc oxide? Give
your reason.
…………………………………………………………………………………………….
…………………………………………………………………………………………….
Prepared by : Siti Zarith binti Abd Wahab
Chemistry Form 4 | 2025
Activity 3.13 : Empirical Formula of Oxide of Copper
Aim
Materials Water, copper(II) oxide powder, zinc granules, 1.0 mol dm–3 hydrochloric acid, wooden
splinter and cotton buds
Apparatus Boiling tube, rubber stoppers, rubber tube, 12 cm glass tube, 10 cm glass tube, spirit
lamp, retort stand with clamp, wooden block, electronic balance and spatula
Procedure
Apparatus
set up
(drawing)
Results Description Mass (g)
Glass tube
Glass tube + oxide of copper
Glass tube + copper
Observation 1) The …………………… color of copper(II) oxide turns ……………………
Inference 1) Copper(II) oxide reacts with hydrogen to produce ………………………
Interpreting Determine the empirical formula of magnesium oxide
data Element Cu O
Prepared by : Siti Zarith binti Abd Wahab
Chemistry Form 4 | 2025
The empirical formula of oxide of copper is ………………………
Discussion 1) What is the purpose of using zinc granules and hydrochloric acid in this activity?
…………………………………………………………………………………………….
2) Why does the hydrogen gas need to flow continuously for a while before starting
the heating process?
…………………………………………………………………………………………….
3) The hydrogen gas is allowed to flow until the product of heating is at room
temperature in step 11. Why?
…………………………………………………………………………………………….
4) How do you ensure that the reaction has completed?
…………………………………………………………………………………………….
5) Write the equation for the reaction that occurred.
…………………………………………………………………………………………….
6) Can this method be used to determine the empirical formula of oxide of lead?
Give your reason.
…………………………………………………………………………………………….
…………………………………………………………………………………………….
7) Can this method be used to determine the empirical formula of zinc oxide? Give
your reason.
…………………………………………………………………………………………….
…………………………………………………………………………………………….
Prepared by : Siti Zarith binti Abd Wahab
