AQA Jun 2014 Paper 1 Q6

Answers available below

section b answer all questions in the spaces provided do not write outside the box a calcium phosphate reacts with aqueous nitric acid to produce phosphoric acid and calcium nitrate as shown in the equation ca po hno h po ca no a i a g sample of calcium phosphate reacted completely when added to an excess of aqueous nitric acid to form cm of solution calculate the concentration in mol dm of phosphoric acid in this solution give your answer to significant figures marks a ii calculate the percentage atom economy for the formation of calcium nitrate in this reaction give your answer to decimal place marks wmp jun chem do not write outside the box b write an equation to show the reaction between calcium hydroxide and phosphoric acid to produce calcium phosphate and water mark c calcium dihydrogenphosphate can be represented by the formula ca h po x where x is an integer a g sample of calcium dihydrogenphosphate contains g of hydrogen g of phosphorus and g of oxygen calculate the empirical formula and hence the value of x show your working marks turn over for the next question turn over wmp jun chem do not write outside the box a thallium is in group of the periodic table thallium reacts with halogens to form many compounds and ions ion and the shape of the tlcl draw the shape of the tlbr include any lone pairs of electrons that influence the shapes ion name the shape made by the atoms in tlbr and suggest a value for the bond angle marks b thallium i bromide tlbr is a crystalline solid with a melting point of c suggest the type of bonding present in thallium i bromide and state why the melting point is high marks c write an equation to show the formation of thallium i bromide from its elements mark end of questions copyright aqa and its licensors all rights reserved wmp jun chem

Show answer