Combustion of Elements in Oxygen

IGCSE Edexcel Chemistry
2.11 Combustion of magnesium, hydrogen and sulfur
Key Concept: Combustion in oxygen forms oxides. Metals form metal oxides and non-metals form non-metal oxides.

Section A: Word and Symbol Equations

1. Write word equations for the combustion of magnesium, hydrogen and sulfur. [3]
2. Write balanced symbol equations for the three reactions in Question 1. [3]

Section B: Observations and Products

3. State one observation for each combustion: magnesium, hydrogen and sulfur. [3]
4. Name the products and classify each as a metal oxide or non-metal oxide. [2]

Total marks: 11

Mark Scheme

1. Magnesium + oxygen -> magnesium oxide; hydrogen + oxygen -> water; sulfur + oxygen -> sulfur dioxide [3]
2. 2Mg + O2 -> 2MgO; 2H2 + O2 -> 2H2O; S + O2 -> SO2 [3]
3. Mg: bright white flame; H2: squeaky pop; S: blue flame/choking smell [3]
4. MgO is a metal oxide; H2O and SO2 are non-metal oxides (water is hydrogen oxide) [2]