St. Patrick's School 2026 Mastery Review (Mid-Year) Chemistry QP

1 NAME CLASS INDEX NO. ST. PATRICK'S SCHOOL MASTERY REVIEW 2026 SUBJECT : CHEMISTRY (6092) DATE : 07 MAY 2026 LEVEL : SECONDARY 4 EXPRESS DURATION : 1 H 45 MINS INSTRUCTIONS TO CANDIDATES: DO NOT OPEN THIS BOOKLET UNTIL YOU ARE TOLD TO DO SO. 1. Write down your name, class and index number on the Question Paper in the spaces provided. 2. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use correction fluid. 3. This paper consists of THREE (3) Sections: Section A, B and C. 4. Answer ALL questions in Section A on the table provided in page 2. 5. Answer ALL questions in Section B and C in the spaces provided. 6. Section C comprises of 2 questions – Question 11 and Question 12. SELECT ONLY ONE QUESTION from this Section. 7. The use of an approved scientific calculator is expected, where appropriate. 8. DO NOT DETACH any sections from this paper. INFORMATION FOR CANDIDATES: The number of marks is given in brackets [ ] at the end of each question. This question paper consists of 26 printed pages, including this cover page and a copy of the Periodic Table. SECTION A : /10 SECTION B : /60 SECTION C Question 11 /10 Question 12 /10 TOTAL /80 GRADE

2 Section A (10 Marks) Each question is provided with four possible answers (A, B, C and D). Select the most appropriate answer and write it in the table provided. 1 2 3 4 5 6 7 8 9 10 1 Hydrogen chloride gas can be produced from the reaction of sodium chloride with sulfuric acid. Which set of apparatus is suitable for preparing and collecting a dry sample of hydrogen chloride? A B C D

3 2 A student uses paper chromatography to find an R f value for Fe 2+(aq). The result is shown. To make the component containing Fe2+(aq) more visible, the paper is sprayed with a solution, V so that a coloured spot, W forms. Which row gives the correct identity of solution V, colour of spot, W and R f value of Fe2+(aq)? solution V colour of spot, W Rf value A aqueous ammonia green x/y B aqueous ammonia reddish-brown y/x C aqueous sodium hydroxide green y/x D hydrochloric acid reddish-brown x/y 3 Some elements on the Periodic Table are shown below. Which row correctly describes W, X, Y and Z? W X Y Z most number of protons least reactive gains electrons most easily A W X Z B W Y Z C Z X W D Z Y W Fe2+ start line solvent front y x

4 4 The structures of four substances are shown. 1 2 3 4 Which statement about the structures is correct? A Structures 3 and 4 are hard and crystalline. B Structures 1 and 3 can conduct electricity in solid state. C Structures 1 and 2 are compounds with high melting points. D Structures 2 and 4 are compounds with giant molecular structures. 5 Alkali metals and halogens react readily to form salts. Which alkali metal and halogen will react most vigorously? alkali metal halogen A lithium fluorine B lithium iodine C potassium fluorine D potassium iodine

5 6 Zinc thiocyanate has the chemical formula Zn(SCN)2. Bismuth oxide has the chemical formula Bi2O3. What is the chemical formula of bismuth thiocyanate? A Bi2SCN B Bi3SCN C Bi(SCN)2 D Bi(SCN)3 7 Which two substances when mixed, will result in an increase of lead(II) ions in solution? A lead and dilute nitric acid B lead(II) oxide and sulfuric acid C aqueous lead(II) nitrate and zinc D lead(II) nitrate and potassium hydroxide 8 A sample of carbonic acid was contaminated with a substance that does not decompose upon heating. Carbonic acid decomposes upon heating to form carbon dioxide and water vapour as the only products. 1.5 g of this mixture was heated in a test -tube until no further change was observed. The final mass of the substance in the test-tube was 0.15 g. What is the percentage purity of the carbonic acid in the sample? A 10 % B 11 % C 45 % D 90 % 9 A solution containing copper ions is electrolysed using inert electrodes. During electrolysis:  0.24 dm³ of oxygen gas is produced at the anode (measured at room conditions)  0.040 mol of copper metal is deposited at the cathode What is the charge on the copper ion in the solution? A +1 B +2 C +3 D +4

6 10 Dilute aqueous sodium chloride is electrolysed using graphite electrodes. Which row gives the correct results of the electrolysis? gases released pH of electrolyte cathode anode A hydrogen chlorine increase B hydrogen oxygen decrease C hydrogen oxygen no change D oxygen hydrogen no change

7 Section B (60 marks) Answer all the questions in this section in the spaces provided. 1 The list below shows the chemical formulae of some compounds. (NH4)2SO4 Ag2CO3 NaBr ZnCl2 CaCl2 FeSO4 Al2O3 KNO3 SiO2 Use the substances in the list to answer the questions below. Each compound can be used once, more than once, or not at all. Identify the compound which: (a) is coloured ………………………………………………………………………………………… [1] (b) can be prepared by precipitation ………………………………………………………………………………………… [1] (c) reacts with both an acid and an alkali ………………………………………………………………………………………… [1] (d) dissolves in water and produces a white precipitate that is insoluble in excess aqueous sodium hydroxide ………………………………………………………………………………………… [1] (e) has an extended network of giant tetrahedral structure. ………………………………………………………………………………………… [1]

8 2 Chemists sometimes use a quantity, 𝑝𝐾𝑎, to describe the strength of acids . A 𝑝𝐾𝑎 value of less than zero denotes a strong acid. During the titration of a weak acid with sodium hydroxide, the pH of the solution when half of the acid has been neutralised is equal to the 𝑝𝐾𝑎value of the acid. The 𝑝𝐾𝑎 value of the acid can be used to confirm the identity of the acid. The chemis t transferred 25.0 cm³ of acid Y into a beaker using a pipette and measured the pH using a pH meter that can be read to one decimal place. A solution of 0.100 mol/dm 3 sodium hydroxide was added from a burette in small portions. After each addition, the pH of the mixture was recorded. The results are shown in Table 2.1 below. Table 2.1

9 (a) Plot a graph of the results in Table 2.1, marking each point with a cross (x). Draw a best -fit line, taking into account all the plotted points, ignoring any inconsistent results. volume of sodium hydrm3 volume of sodium hydroxide in cm3 [3] pH

10 (b) Use your graph from (a) to determine the (i) volume of sodium hydroxide solution at the end-point of the titration (end point of titration is halfway up the steep curve, where the H + ions are completely neutralized by OH