2024 Y5 DHS H2 Chemistry Timed Practice 1

1 © DHS 2024 DUNMAN HIGH SCHOOL 2024 YEAR 5 H2 CHEMISTRY TIME PRACTICE 1 Mole Concept, Redox & Atomic Structure Name : Date: ___________ Duration: 50 minutes Class : Section A – Multiple Choice Questions Answer all questions. Write your answers in the boxes below. MCQ No. 1 2 3 4 5 Your Answer 1 Use of Data Booklet is relevant to this question. Which statement about a 20.3 g sample of Co2(SO4)3 (Mr = 406) is incorrect? A It contains 1.5 × 1023 ions. B It contains 0.1 mol of Co3+ ions. C It contains 14.5% of cobalt by mass. D It contains 47.3% of oxygen by mass. 2 In an experiment, Fe3+ oxidises X3+(aq) in acidic medium, while itself is reduced to Fe2+. 20.0 cm3 of 0.0120 mol dm –3 X3+(aq) was found to require 24.00 cm 3 of 0.0300 mol dm –3 Fe3+ for complete oxidation. What is the formula of the X-containing species formed? A XO+ B XO2+ C XO22+ D X2O22+ Qn MCQ Q6 Q7 Q8 Q9 Total % Grade Marks 5 6 3 6 10 30

2 © DHS 2024 3 The successive ionisation energies (IE) of two elements, M and N, are given below. IE / kJ mol–1 1st 2nd 3rd 4th 5th 6th 7th 8th M 550 1065 4138 5500 6910 8760 10230 11800 N 1140 2103 3470 4560 5760 8550 9940 18600 What is the most likely formula of the compound that is formed between M and N? A MN B MN2 C M2N D M3N2 4 When passed through an electric field, the 1H+ ion is deflected as shown below. Which of the above beams represents the deflection for the ion 2D–? (D = H1 2 ) 5 Use of Data Booklet is relevant to this question. Some isotopes are unstable and undergo nuclear (radioactive) reactions. In one type of reaction, an unstable nucleus assimilates an electron from an inner orbital of its electron cloud. The net effect is the conversion of a proton and an electron into a neutron. 10 1 -1p + e → 1 0n Which of the following is an example of this type of reaction? A 11C → 12C B 111I → 111Te C 76Br → 75Br D 76Kr → 75Br A B C D 1H+ ion 4o 4 o + − source

3 © DHS 2024 Section B – Structured Questions Answer all questions in the space provided. Marks will be allocated for relevant working. 6 Verdigris was the most vibrant green pigment available and was frequently used in painting until the 19th century. Verdigris is resistant to fading when it is exposed to light, as numerous examples of the paintings show. This pigment was made by hanging copper foil over boiling vinegar. (a) During the preparation of verdigris, copper atoms are oxidised to copper( II) ions , Cu 2+. Oxygen is reduced to water in acidic medium. (i) Write half–equations for both the reduction and oxidation reactions. Hence write the balanced equation for the reaction between Cu and O2. Reduction: ………………………………………………………………………………...…… Oxidation: ……………………………………………………………………………………... Overall: ..…………………………