Period 3 reactions and oxides

The pH of a solution formed when sulfur(IV)oxide dissolves in water is:

• 3

• 2

• 1

• 0

Which of these are correct for when magnesium reacts with steam

• A bright white flame is seen

• Magnesium hydroxide is produced

• A white powder is produced

• The hydrogen gas produced is flammable

Silicon dioxide is:

• Giant

  Covalent

  High melting point

  Amphoteric

• Giant

  Ionic

  High melting point

  Amphoteric

• Giant

  Covalent

  High melting point

  Basic

• Giant

  Covalent

  High melting point

  Acidic

The pH of a solution formed when phosphorus(V)oxide dissolves in water is:

• 3

• 0

• 1

• It is insoluble

Which of these is NOT true for the reaction between sodium and water?

• The metal floats and moves on the surface

• Sodium hydroxide is produced which dissolves and makes the solution alkaline

• The reaction is very endothermic

• Hydrogen is also produced

Answer explanation

The reaction is very EXOthermic - this melts the sodium into a ball.

The pH of a solution formed when sulfur(VI)oxide dissolves in water is:

• 3

• 2

• 1

• 0

Which formula of a phosphate is incorrect?

• Mg₂(PO₄)₃

• Na₃PO₄

• AlPO₄

• Mg₃(PO₄)₂

Which 2 statements are true about sodium oxide?

• It is metallic

• It has the formula NaO₂

• It has a high melting point

• It is soluble in water

Aluminium oxide is:

• Giant

  Ionic

  High melting point

  Acidic

• Giant

  Ionic

  High melting point

  Amphoteric

• Giant

  ionic

  High melting point

  Basic

• Metallic

  High melting point

  Amphoteric

Which fact about SO₃ is incorrect

• It is trigonal planar

• It dissolves in water to form a solution with a pH of 0

• It is polar

• It is a colourless liquid at room temperature