AQA A level Chemistry - test tube reactions Questions and Answers

AQA A level Chemistry - test tube reactions Questions and Answers Bromide Ions and Chlorine Yellow/Orange solution Cl2 + 2Br- = Br2 + 2Cl Iodide ions and chlorine Yellow/brown solution Cl2 + 2I- = I2 + 2Cl- Chloride Ions and Bromine Yellow/orange solution No reaction Chloride Ions and Iodine Yellow/Brown solution No reaction Bromide Ions and Iodine Yellow/Brown solution No reaction Iodide ions and Bromine yellow/brown solution Br2 + 2I- = I2 +Cl- Magnesium and H2SO4 no visible reaction - MgSO4 is soluble Calcium and H2SO4 no visible reaction - CaSO4 is soluble Strontium and H2SO4 faint white precipitate - SrSO4 Barium and H2SO4 white precipitate - BaSO4 is insoluble Trend in solubility of Group 2 sulfates Decreases down the group F- and silver nitrate/ammonia no precipitate Cl- and silver nitrate/ammonia White precipitate - dissolves in dilute NH3 Br- and silver nitrate/ammonia cream precipitate - dissolves in conc NH3 I- and silver nitrate/ammonia Yellow precipitate - insoluble in NH3 Cl- and conc H2SO4 NaCl + H2SO4 == HCl + NaHSO4 - steamy fumes Br- and conc H2SO4 2Br- + H2SO4 + 2H+ == Br2 + SO2 + 2H2O - steamy fumes with browny vapour and colourless gas I- and conc H2SO4 H2SO4 + 8I- + 8H+ == 4I2 + H2S + 4H2O - bad egg smell Trend in reducing power of halides increases down the group