MI Prelim H1 Chem P1 Ans_for exchange

Class Adm No Candidate Name: This question paper consists of 14 printed pages and 2 blank pages 2025 Preliminary Examination Pre-University 2 H1 CHEMISTRY 8873/01 Paper 1 Multiple Choice 17 September 2025 1 hour Additional materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Do not turn over this question paper until you are told to do so Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, class and admission number in the spaces provided at the top of this page and on the Multiple Choice Answer Sheet provided. There are thirty questions on this paper. Answer ALL questions. For each question there are four possible answers A, B, C and D. Choose the one you consider correct and record your choice in soft pencil on the Multiple Choice Answer Sheet provided. Read the instructions on the Multiple Choice Answer Sheet very carefully. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. Any rough working should be done in this question paper. The use of an approved scientific calculator is expected, where appropriate. FOR EXAMINER’S USE TOTAL (30 marks) H

2 MCQ ANSWERS 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 C B B A D B C D C C B C A B D 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 A B C C B D B A D B A B C C C 1 Which of the following statements about 1 mol of a gas is always correct? A It has the same mass as any gas with 6.02 × 1023 molecules. B It has the same number of atoms as 1 mol of hydrogen gas. C It occupies the same volume as 1 mol of H2S gas under the same conditions. D It contains the same number of particles as 1 12 g of 12C. C - 1 mol of any gas occupies the same volume as each other, under the same conditions. X Option A - 6.02 × 1023 gas molecules  1 mole gas  molar mass of the gas - different gases have different molar masses. X Option B - the gas may exist as monatomic  has 6.02 × 1023 atoms - H2 gas consists of diatomic molecules  1 mol H2 gas  2 x 6.02 × 1023 atoms. X Option D For the 1 mol gas: - if it were a monatomic gas  6.02 × 1023 atoms - if it were a diatomic gas  2 x 6.02 × 1023 atoms - if it were a tri-atomic gas  3 x 6.02 × 1023 atoms Whereas: 1 12 g of 12C  1 12  12 mol of 12C  1 12 g of 12C  0.00694 mol of 12C  0.00694 mol of 12C  0.00694 x 6.02 × 1023 atoms of 12C atoms

3 [Turn over 2 In an experiment, 50 cm3 of a 0.1 mol dm−3 solution of a metallic salt reacts exactly with 25 cm3 of 0. 1 mol dm −3 aqueous sodium sulfite, Na 2SO3. The half -equation for the oxidation of the sulfite ion is shown below: SO32−(aq) + H2O(l) ⟶ SO42−(aq) + 2H+(aq) + 2e− If the original oxidation numb