A Levels Chemistry

Boron is a non-metallic element which is placed above aluminium in Group III of the Periodic
Table. It forms a compound with nitrogen known as boron nitride which has a graphite structure.
Which of the following conclusions can be drawn from this information?
1 The empirical formula of boron nitride is BN.
2
The boron and nitride atoms are likely to be arranged alternately in a hexagonal pattern.
Boron nitride has a layer structure with van der Waals' forces between the layers.


Choice A is correct because:

The empirical formula of boron nitride is BN. 

This statement is correct because boron nitride is a binary compound composed of boron and nitrogen, and the empirical formula represents the simplest whole-number ratio of these elements in the compound, which is 1:1.

The boron and nitride atoms are likely to be arranged alternately in a hexagonal pattern. 

This statement is correct because boron nitride has a graphite structure, which consists of a hexagonal arrangement of atoms. In the case of boron nitride, boron and nitrogen atoms are arranged alternately in this hexagonal pattern.

Boron nitride has a layer structure with van der Waals' forces between the layers. 

This statement is correct because, like graphite, boron nitride has a layered structure with weak van der Waals' forces between the layers. This allows the layers to slide past one another, giving boron nitride similar properties to graphite, such as lubricating ability.

Choice B is incorrect because:

While statements 1 and 2 are correct, this choice omits statement 3, which is also correct.

Choice C is incorrect because:

While statements 2 and 3 are correct, this choice omits statement 1, which is also correct.

Choice D is incorrect because:

Statement 1 is correct, but this choice does not include statements 2 and 3, which are also correct.

States of Matter | 2005 - O/N - 9701/1 | Q33