GCSE CHEMISTRY Higher Tier Paper 2

GCSE CHEMISTRY Higher Tier Paper 2 H Downloaded by nipsey scott () lOMoARcPSD| 2 *02* IB/M/Jun23/8462/2H Do not write outside the 0 1 box A student investigated the rate of the reaction between zinc and sulfuric acid. Hydrogen gas is produced during this reaction. Figure 1 shows the apparatus. Figure 1 This is the method used. 1. Add 50 cm3 of sulfuric acid to a conical flask. 2. Add 2.0 g of zinc to the conical flask. 3. Quickly put a stopper in the conical flask and start a timer. 4. Measure the time taken to collect 20 cm3 of gas. 5. Repeat steps 1 to 4 three more times. 0 1 . 1 Suggest why the stopper must be put in the conical flask as quickly as possible in step 3. [1 mark] Downloaded by nipsey scott () lOMoARcPSD| 3 *03* Turn over ► IB/M/Jun23/8462/2H Do not write outside the 0 1 box . 2 The student calculated the rate of the reaction for each trial. Table 1 shows the results of the calculations. Table 1 Trial 1 Trial 2 Trial 3 Trial 4 Rate of reaction in cm3 /s 0.78 0.81 0.68 0.81 Determine the mean time taken to collect 20 cm3 of gas. Do not include any anomalous results. Use the equation: mean rate of reaction = volume of gas collected mean time taken [5 marks] Mean time taken = s Question 1 continues on the next page Downloaded by nipsey scott () lOMoARcPSD| 4 *04* IB/M/Jun23/8462/2H Do not write outside the 0 1 box . 3 The student changed the investigation so that the mean time taken to collect 20 cm3 of gas was greater. Which two changes would increase the mean time taken to collect 20 cm3 of gas? [2 marks] Tick () two boxes. Use a catalyst Use a larger conical flask Use a lower temperature Use smaller pieces of zinc Use sulfuric acid of a lower concentration 0 1 . 4 Hydrogen gas is produced during this reaction. Describe the test for hydrogen gas. Give the result of the test. [2 marks] Test Result 10 Downloaded by nipsey scott () lOMoARcPSD| 5 *05* Turn over ► IB/M/Jun23/8462/2H Do not write outside the Turn over for the next question box DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED Downloaded by nipsey scott () lOMoARcPSD| 6 *06* IB/M/Jun23/8462/2H Do not write outside the 0 2 This question is about alcohols and carboxylic acids. box Alcohols are used as fuels. A student burned 1.00 g of six alcohols and determined the energy released from each. Table 2 shows the results. Table 2 Alcohol Formula of one molecule of the alcohol Energy released in kJ/g Ethanol C2H5OH 29.6 Propanol C3H7OH 33.6 Butanol C4H9OH 36.1 Pentanol C5H11OH 37.7 Hexanol C6H13OH 38.9 Heptanol C7H15OH 39.8 0 2 . 1 Calculate the mass of ethanol that must be burned to release the same amount of energy as burning 1.00 g of heptanol. [2 marks] Mass = g 0 2 . 2 The energy released in kJ/g varies with the number of carbon atoms in one molecule of each alcohol. Plot the data from Table 2 on Figure 2. [2 m