2023 Paper 4 QP with Data

Upon adding KI (aq), pale yellow solution turns orange Upon standing, orange solution turns brown. On adding FA2, brown solution turns yellow, then green and eventually blue. When FA3 is added, pale yellow solutions turns green, then blue, then darker blue. Effervescence is observed. (Not required to test for gas) On adding all of FA4, blue solution turns violet/purple. Effervescence is observed. (Not required to test for gas) Red-brown solid is formed. Upon standing, purple solution turns blue. Scan QR code for QA Video 2023 A level H2 Chem Paper 4

Experiment 1 Time / min Burette reading / cm3 Volume of gas collected / cm3 0.0 49.8 1.0 39.4 2.0 28.4 3.0 16.6 4.0 8.9 5.0 7.3 6.0 7.2 Experiment 2 Time / min Burette reading / cm3 Volume of gas collected / cm3 0.0 50.0 1.0 43.0 2.0 35.4 3.0 27.8 4.0 24.0 5.0 23.6 6.0 23.2

Titration 1 2 Final Burette reading / cm3 15.10 15.10 Initial Burette reading / cm3 0.00 0.10 Volume of FA6 used /cm3 15.10 15.00