AQA AS Chemistry Paper 1: Inorganic and Physical Chemistry Questions & Correct Answers/ Graded A+

Give the full electron configuration of an Al atom and a Cr3+ ion : 1s2 2s2 2p6 3s2 3p1 1s 2s2 2p6 3s2 3p6 3d6 Deduce the formula of the ion that has a charge 2+ with the same electron : Sr2+ Deduce the formula of the compound that contains 2+ ions and 3- ions that both have the same electron configuration as argon : CaP Deduce which of Na+ and Mg2+ is the smaller ion 2 marks : Mg 2+ 2 Both have the same number of shielding however Mg2+ has more protons so higher nuclear charge and so stronger attraction between out electrons and nucleus so smaller atomic radius First ionisation of sodium : Na(g) -> Na+ + eExplain why the first ionisation of sulfur is lower than phosphorus 4 marks : Sulfur has a pair of electrons in its 3p orbital Phosphorus has 3 unpaired electrons in its 3p orbital Pair of electrons repel and electron is easily removed Less energy is needed to remove the electron This question is about a white solid MHCO3 that dissolves in water and reacts with HCl to give a salt Samples of the solution were titrated Student identified burette as the largest source of uncertainty in the experiment. Suggest how the procedure could be improved to reduce the percentage uncertainty in using the burette 3 Justify your suggested improvement 2 marks : Use larger mass of solid So larger reading will be needed