OCR 2023 Chemistry A H432/01: Periodic table, elements and physical chemistry A Level Question Paper & Mark Scheme (Merged)

2 OCR 2023 Section A You should spend a maximum of 20 minutes on this section. Write your answer to each question in the box provided. 1 Which sample contains the greatest number of molecules? A 35.0 g of C2H2 B 45.0 g of C2H6 C 60.0 g of C4H10 D 100.0g of C6H6 Your answer [1] 2 0.688g of an oxide of manganese is reduced by hydrogen gas to form manganese metal and 0.235g of water. What is the formula of the oxide of manganese? A MnO B MnO2 C Mn2O3 D Mn3O4 Your answer [1] 3 How many hydrogen atoms are in 2.50 g of pharmacolite, CaHAsO4 •2H2O (Mr = 216.0)? A 6.97 × 1021 B 2.09 × 1022 C 2.79 × 1022 D 3.48 × 1022 Your answer [1] 3 OCR 2023 Turn over 4 40.0 cm3 of 0.200 mol dm–3 HCl is added to 60.0 cm3 of 0.100 mol dm–3 NaOH. What is the concentration of the resulting solution? A 0.0200 mol dm–3 HCl and 0.0200 mol dm–3 NaCl B 0.0200 mol dm–3 HCl and 0.0400 mol dm–3 NaCl C 0.0200 mol dm–3 HCl and 0.0600 mol dm–3 NaCl D 0.0600moldm–3 HCl and 0.0200moldm–3 NaCl Your answer [1] 5 Which compound has polar molecules?