CIE Mar 2017 v2 Paper 4 Q1

Answers available below

Answer all the questions in the spaces provided. PMT (a) (i) The mass spectrum of silicon is shown. 1.0 0.922 relative intensity 0.5 28 0.047 29 m / e 0.031 30 Calculate the Ar of silicon. Give your answer to two decimal places. Ar =[1] (ii) Silicon forms a low boiling point chloride which reacts with water. Write an equation to show the reaction of the chloride with water.[1] (iii) Draw a three-dimensional diagram showing the shape of the chloride. Give the ClSiCl bond angle. [2]UCLES 2017 9701/42/F/M/17<br /> PMT (iv) Silicon reacts with oxygen to form a high melting point oxide. Suggest the formula of the oxide.Suggest, in terms of structure, why the oxide has a high melting point whereas the chloride has a low boiling point.[2] (b) Element A is in the same period as silicon. Element A reacts with dilute nitric acid to form a nitrate. This nitrate decomposes on heating to form an oxide. (i) Write an equation for the decomposition of the nitrate.[2] (ii) The oxide of element A has a high melting point. Suggest the structure and bonding present in the oxide of A.[1] [Total: 9]UCLES 2017 9701/42/F/M/17 [Turn over<br />

Show answer