Chemistry 9701 · AS & A Level · The Periodic Table: chemical periodicity

The Periodic Table: chemical periodicity — practice question

Solid sodium is able to conduct electricity. Sodium oxide conducts electricity only when it is molten, not while it remains solid.
(a(i))[1]

State the bonding type present in sodium and in sodium oxide. Bonding in sodium ……… Bonding in sodium oxide ………

(a(ii))[1]

Explain the way solid sodium conducts electricity.

(a(iii))[1]

Explain why sodium oxide conducts electricity when molten.

(b(i))[1]

Write an equation for sodium reacting with cold water.

(b(ii))[1]

Write an equation for sodium oxide reacting with cold water.

(b(iii))[2]

Complete Table 1.1. When describing what is seen for these reactions, do not mention temperature changes. Give one similarity and one difference in the observations when sodium and sodium oxide are added to cold water.

(c)[2]

State the oxidation number of the Period 3 elements bonded to $ ext{Cl}$ in $ ext{NaCl}$ and $ ext{PCl}_5$. Explain why the oxidation number is different.

(d)[2]

Table 1.2 shows melting points of some oxides. A student suggests the following hypothesis: The higher the oxidation number of the element combined with oxygen, the higher the melting point of the oxide. Use Table 1.2 to deduce if this hypothesis is true or false or if there is not enough information to make a conclusion. Explain your answer.

Worked solution & mark scheme

This 11-mark question has a full step-by-step worked solution and mark scheme. One marking point: sodium is metallic AND sodium oxide is ionic

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