Period 3 oxides: structure and acid-base characterAQA A-Level Chemistry: Mind map

Exam questions on Period 3 oxides: structure and acid-base character

1. A student is given samples of four Period 3 oxides, sodium oxide, magnesium oxide, silicon dioxide and phosphorus(V) oxide, and is asked to compare their melting points.
   Explain why the melting point of magnesium oxide is higher than that of sodium oxide.2 marks
2. A student adds small amounts of sodium oxide, aluminium oxide and phosphorus(V) oxide to separate beakers of water and tests the pH of each mixture with universal indicator.
   Write an equation for the reaction of sodium oxide with water and explain why the resulting solution is alkaline.2 marks
3. A technician is preparing a safety sheet for the oxides of Period 3. She needs equations for the acids formed when phosphorus(V) oxide, sulfur dioxide and sulfur trioxide dissolve in water, and a description of the structures of some of the acids and anions involved.
   Write equations for the reactions of phosphorus(V) oxide, sulfur dioxide and sulfur trioxide with water.3 marks