Which of the following Period 3 element forms an oxide with the highest oxidation number?

• Silicon

• Phosphorus

• Sulphur

• Chlorine

A compound X with a high melting point dissolves in water and conduct electricity in molten state. Compound X most probably is

• K₂CO₃

• MgO

• AlCl₃

• SrSO₄

An oxide G has a boiling point 2230⁰C. It dissolves in aqueous sodium hydroxide solution but not in water and acid. Oxide G is

• PbO₂

• P₂O₅

• SiO₂

• Al₂O₃

Which oxide of an element dissolves in water to form an acidic solution?

• Na

• Mg

• Si

• P

State acid-base property for MgO and SiO₂.

Which element has an oxide which dissolves in water to form an acidic solution?

• Al

• Na

• P

• Si

Which oxide will produce 1.0 mol dm^-3 aqueous solution with the lowest pH value?

• Na₂O

• MgO

• P₂O₅

• SO₃

Choose the correct statements.

• SiO₂ and P₄O₁₀ are covalent oxides.

• SiO₂ is neutral and insoluble in water.

• Al₂O₃ dissolves in water; aqueous acid; alkali.

• P₄O₁₀ is hydrolysed in water to form H₃PO₄.

What can be deduced based on the reaction scheme above?

• W is a reducing agent

• W conducts electricity

• W has a giant structure

An oxide of Period 3 of the Periodic Table element reacts with water to form a strong acid. The oxide is

• Polar

• An oxidising agent

• dichlorine heptoxide, Cl₂O₇

• from Group 15 element