A Group 2 metal combines with bromine to form a crystalline solid, MBr2. Excess aqueous AgNO3 is added to a solution of MBr2 and a precipitate forms. The mixture is filtered. The precipitate is dried and the mass of the precipitate is recorded.

1. (a)State the formula and colour of the precipitate.[2]
2. (b)Complete the equation to represent the reaction between MBr2 and AgNO3. .MBr2 + ......AgNO3 → [1]
3. (c)A 0.250 g sample of pure MBr₂ contains 8.415 × 10–4 mol MBr2. Calculate the relative formula mass, Mr, of MBr2. Use this to identify M. Show your working. M = M =[3]
4. (d)(i)A sample of MBr2 is dissolved in water. Chlorine gas is then bubbled into the solution. Describe the observations for this reaction.[1]
5. (d)(ii)Name the type of reaction that occurs when MBr₂ reacts with chlorine gas.[1]
6. (e)Compound Y is a pure insoluble solid which contains halide ions. A single reagent is added directly to compound Y to determine the halide ion present. Identify the reagent added. State the observation which would confirm that Y contains bromide ions. reagent observation[2]
7. (f)(i)Separate 1.0g samples of three different magnesium salts are tested in order to identify the anion present in each sample. Explain how the action of heat is used to identify which sample is: • MgCO3 • Mg(NO3)2 • MgO.[3]
8. (f)(ii)Complete the electron configuration of the magnesium cation present in these salts. 1s2[1]
9. (g)A sample of MgCO3(s) is distinguished from a sample of Mg(OH)2(s) by adding a small amount of each solid to HCl(aq). State one similarity and one difference in these two reactions. similarity difference[2]