2021 RVHS Prelim P1 QP

River Valley High School 9729/01/PRELIMS/21 2021 Preliminary Examination [Turn over RIVER VALLEY HIGH SCHOOL JC 2 PRELIMINARY EXAMINATION CANDIDATE NAME CLASS 2 0 J CENTRE NUMBER S INDEX NUMBER H2 CHEMISTRY 9729/01 Paper 1 Multiple Choice 23 September 2021 1 hour Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, class, centre number and index number on the Answer Sheet in the spaces 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 separate Answer Sheet. Read the instructions on the 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 booklet. The use of an approved scientific calculator is expected, where appropriate. This document consists of 14 printed pages and 2 blank pages.

2 River Valley High School 9729/01/PRELIMS/21 2021 Preliminary Examination 1 When potassium chlorate( V) KC lO3, is heated at its melting point, it disproportionates to potassium chlorate(VII) KClO4, and potassium chloride. What is the maximum number of moles of potassium chlorate( VII) which could be produced from 0.200 mol of potassium chlorate(V)? A 0.200 B 0.150 C 0.100 D 0.0500 2 Methane was burned in an incorrectly adjusted Bunsen burner. The methane was converted into a mixture of carbon dioxide and carbon monoxide in the ratio 99:1, together with water vapour. What will be the volume of oxygen consumed when y dm3 of methane is burned? A 30.01y( 2y ) dm2 B 3( 2y 0.01y ) dm C 30.01y( y ) dm2 D 3( y 0.01y ) dm 3 Use of the Data Booklet is relevant to this question. The table shows the fifth, sixth, seventh, eighth and ninth ionisation energies of three elements in the third period. Ionisation energy/ kJ mol‒1 5th 6th 7th 8th 9th Element A 6274 21267 25431 29872 35905 Element B 7004 8496 27107 31719 36621 Element D 6542 9362 11018 33604 38600 Which statements are correct? 1 The first ionisation energy of A is lower than that of B. 2 The atom of element A will be isoelectronic with D2+. 3 A and D forms an ionic solid AD3. A 1 and 3 only B 2 and 3 only C 1 only D 2 only

3 River Valley High School 9729/01/PRELIMS/21 2021 Preliminary Examination [Turn over 4 In which order are the electrons lost in forming Ga4+ ion? 1st 2nd 3rd 4th A 3d 4p 4s 4s B 3d 4s 4s 4p C 4p 4s 3d 3d D 4p 4s 4s 3d 5 Which pair of liquids, when mixed, will give out heat? A CH2Cl2 and CH3COCH2CH3 B CH2Cl2 and C6H12 C CF4 and COCl2 D CCl4 and C10H21OH 6 A 10 m 3 of oxygen gas at a pressure of 50 kPa and 30 m 3 of nitrogen gas at a pressure of 100 kPa are introduced to a 15 m 3 vessel at 300 K. The pressure in the vessel after mixing is E kPa. Subsequently, the 15 m3 vessel is heated to a temperature of F K and total pressure at F K is 350 kPa. Given that the gases do not react at all temperatures, what are the values of E and F? E kPa F K A 233 401 B 233 451 C 400 263 D 400 343

4 River Valley High School 9729/01/PRELIMS/21 2021 Preliminary Examination 7 A molecule of BCl3 is planar, whereas a molecule of PH3 is pyramidal. Which statements are responsible for the difference in shapes? 1 The repulsion between chlorine atoms is greater than that between hydrogen atoms. 2 The boron atom in BCl3 has six electrons in its valence shell, whereas the phosphorus atom in PH3 has eight. 3 The atomic radius of phosphorus is greater than that of boron. A 1 only B 2 only C 1 and 3 only D 2 and 3 only 8 When water is stirred with glucose, strong hydrogen bonds are initially formed between glucose molecules and water molecules. As more water is added, these hydrogen bonds are broken. Which of these graphs best represents the observed temperature changes? A C B D temperature volume of water added temperature volume of water added temperature volume of water added temperature volume of water added

5 River Valley High School 9729/01/PRELIMS/21 2021 Preliminary Examination [Turn over 9 Highly toxic disulfur decafluoride decomposes by a free-radical process. S2F10(g)  SF4(g) + SF6(g) In a study of the decomposition, S2F10 was placed in a 2.0 dm3 flask and heated to 100 C. The equilibrium [S2F10] was found to be 0.5 mol dm−3. More S2F10 was then added and the new equilibrium [S2F10] was 2.5 mol dm−3. What is the amount of S2F10 reacted in terms of the equilibrium constant, Kc of the decomposition reaction when more S2F10 was added? A (0.5Kc)0.5 − (2.5Kc)0.5 B (2.5Kc)0.5 − (0.5Kc)0.5 C (2Kc)0.5 − (10Kc)0.5 D (10Kc)0.5 − (2Kc)0.5 10 Nitrogen oxide reacts with hydrogen gas as shown in the equation below. 2NO(g) + 2H2(g)  N2(g) + 2H2O(g) The reaction was determined to be second order with respect to NO and first order with respect to H2. In an experiment, 2.0 mol dm–3 of excess NO was used to react with H 2, the concentration of H 2 decreased to 6.25% of its original value in 24 minutes. How many minutes will it take for the concentration of H2 to decrease to 6.25% of its original value if the experiment was repeated using an excess of 4.0 mol dm –3 of NO? A 1.5 B 4.5 C 6.0 D 9.0 11 Use of the Data Booklet is relevant to this question. Water dissociates as follows: H2O(l)  H+(aq) + OH(aq) At 25 °C, the equilibrium value of [H+] = 107 mol dm3 and [H2O] = 1000 18 mol dm6. In which order would the numerical value of pH, p Ka and p Kw increase for this equilibrium at 25 °C? smallest largest A pH pKa pKw B pH pKw pKa C pKa pKw pH D pKw pKa pH

6 River Valley High School 9729/01/PRELIMS/21 2021 Preliminary Examination 12 The following reaction occurs when light is shone for a fixed period into a solution of CH2ICH2I and I2 in tetrachloromethane at 100 °C. CH2ICH2I → CH2=CH2 + I2 What conclusions about the rate of formation of iodine can be drawn from the data in the table? experiment relative initial concentrations relative light intensity relative initial rate of formation of iodine CH2ICH2I I2 1 2 1 4 2 2 2 1 1 1 3 1 1 4 1 4 1 2 4 1 1 proportional to light intensity 2 independent of initial concentration of I2 3 proportional to initial concentration of CH2ICH2I A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 1 only 13 Which equations represent a Brønsted-Lowry acid-base reaction? 1 C6H6 + Br+  [C6H6Br]+ 2 CH3CH2NH3+ + NH3  CH3CH2NH2 + NH4+ 3 CH3CH2+ + Br –  CH3CH2Br A 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

7 River Valley High School 9729/01/PRELIMS/21 2021 Preliminary Examination [Turn over 14 The numerical values of the solubility product of BaSO 4, BaCO3 and Ba(IO3)2 at 25 °C are given in the table below. Compound Solubility product BaSO4 1.1  1010 BaCO3 2.6  109 Ba(IO3)2 4.0  109 An aqueous solution of BaC l2 was added slowly, until in excess, to a solution containing 0.5 mol dm3 Na2SO4, 1.0 mol dm3 Na2CO3 and 1.5 mol dm3 NaIO3 at 25 °C. What is the correct order of precipitation of the three barium salts? First to precipitate Last to precipitate A BaSO4 BaCO3 Ba(IO3)2 B Ba(IO3)2 BaCO3 BaSO4 C BaSO4 Ba(IO3)2 BaCO3 D BaCO3 Ba(IO3)2 BaSO4 15 Which factors determine the total amount of oxygen produced at the anode during the electrolysis of aqueous sodium fluoride? mass of electrode current time A   ✘ B  ✘ ✘ C ✘   D ✘ ✘ 

8 River Valley High School 9729/01/PRELIMS/21 2021 Preliminary Examination