WAEC - Chemistry (2001 - No. 45)
Which of the following substances increases in mass when heated in air?
Sodium chloride
lodine crystals
magnesium ribbon
copper (ll) oxide
Selitys
The mass of magnesium ribbon increases when heated in air because it combines with oxygen to form magnesium oxide, a white powder:
The chemical equation for this reaction is:
2Mg + O2 → 2MgO