WAEC - Chemistry (2015 - No. 30)
Which of the following oxides can be reduced by hydrogen?
Aluminium oxide
Magnesium oxide
Sodium oxide
Silver oxide
Vysvetlenie
Considering the electrochemical series, we can say that hydrogen can reduce only oxides of copper, mercury, silver, and gold as these metals are less reactive than hydrogen. The reduction of oxides of tin, iron, zinc, magnesium, calcium, and potassium is not possible by hydrogen as these metals are more reactive than hydrogen