NYGH 2018-S3MYE-IP Chem

Class Register Number Name NANYANG GIRLS' HIGH SCHOOL Mid-Year Examination 2018 Secondary Three IP Chemistry CHEMISTRY 1 hour 30 minutes Monday 7 May 2018 0845 - 1015 READ THESE INSTRUCTIONS FIRST Write your class, register number and name in the spaces at the top of this page. Do not use paper clips, glue or correction fluid. There are 3 sections in this paper. Section A 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 the Multiple-Choice Answer Sheet provided. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. Section B and C Answer all questions. The number of marks is given in brackets [ ] at the end of each question or part question. Candidates are reminded that all quantitative answers should include appropriate units. The use of an approved scientific calculator is expected, where appropriate. Candidates are advised to show all their working in a clear and orderly manner. A copy of the Periodic Table is on page 18. Section A (20 marks) Section B (30 marks) Section C (10 marks) Total (60 marks) Setter: KXY, NHK, CT This document consists of 18 printed pages. NANYANG GIRLS' HIGH SCHOOL [Turn over

2018 Mid-Year Examination Secondary Three IP Chemistry 2 Nanyang Girls’ High School Setter: KXY, NHK, CT 1 Which of the following is not a factor affecting rate of diffusion? A concentration gradient B relative molecular mass C temperature D volume 2 Below is a table showing the melting and boiling points of two metals, gallium and mercury. Both metals have been used in thermometers. metal melting point/ °C boiling point/ °C gallium 29.8 2400.0 mercury –38.8 356.7 Which of the following describes the movement of their metal atoms at 20.0 °C? gallium mercury A vibrate about fixed positions vibrate about fixed positions B vibrate about fixed positions slide across neighbouring atoms C slide across neighbouring atoms slide across neighbouring atoms D slide across neighbouring atoms move randomly in all directions 3 There are three methods to collect gases: I upward delivery II downward delivery III displacement of water When magnesium metal is placed in a solution of hydrochloric acid, which method(s) could be used to collect the gas produced? A I only B II only C I and II only D I and III only Section A Answer all questions. Choose the answer you consider correct and record your choice in the Multiple-Choice Answer Sheet provided.

2018 Mid-Year Examination Secondary Three IP Chemistry 3 Nanyang Girls’ High School Setter: KXY, NHK, CT [Turn Over] 4 Which of the following is the best drying agent to obtain a dry sample of ammonia gas? A concentrated sulfuric acid B solid calcium oxide C solid calcium carbonate D sodium hydroxide 5 50 cm3 of distilled water was added to 50 cm3 of 1 mol dm–3 of sulfuric acid. Which of the following statements best describes the change in the solution? A The pH of the solution is halved. B The solubility of the solution is halved. C The concentration of hydrogen ions is halved. D The number of hydrogen ions dissociated from sulfuric acid molecules is halved. 6 The following table gives some information on different pH indicators: indicator colour at pH 1 pH at which colour changes colour at pH 14 congo red blue 5 red bromothymol blue yellow 6 blue phenophthalein colourless 10 red What colour would be observed if 2 drops of each indicator were added to the same sample of distilled water? A green B purple C blue D orange 7 Tin(II) oxide (SnO) is a blue black solid at room temperature. It is insoluble in water, but dissolves in hydrochloric acid as well as concentrated sodium hydroxide solution. What type of oxide is tin(II) oxide? A acidic B amphoteric C basic D neutral

2018 Mid-Year Examination Secondary Three IP Chemistry 4 Nanyang Girls’ High School Setter: KXY, NHK, CT 8 5 g of zinc carbonate was added to 50 cm3 of 1 mol dm3 sulfuric acid. After some time, effervescence stopped. Why does this occur? A The H+ ions was fully used up. B The gas formed dissolved in water. C The zinc carbonate was fully used up. D An insoluble coating was formed around the zinc carbonate powder. 9 In the preparation of aluminium nitrate, excess aluminium metal was added to nitric acid. Which of the following pH graphs best represents this reaction? A B C D 10 Which of the following shows the correct method to prepare lithium nitrate and chromium(III) nitrate? lithium nitrate chromium(III) nitrate A titrate LiOH with HNO3 titrate Cr(OH)3 with HNO3 B titrate LiOH with HNO3 Add Cr2O3 in excess to HNO3 C add Li metal in excess to HNO3 Add Cr metal in excess to HNO3 D add Li2O in excess to HNO3 Add CrCl3 solution to HNO3

2018 Mid-Year Examination Secondary Three IP Chemistry 5 Nanyang Girls’ High School Setter: KXY, NHK, CT [Turn Over] 11 Crystallisation separates the solute from the solvent based on which of the following properties? A difference in densities B difference in boiling points C difference in molecular mass D difference in solubility of the solute at different temperatures 12 Solution Y is titrated with solution X to obtain the following graph: Which of the following could be the identity of X and Y? X Y A ethanoic acid sodium hydroxide B hydrochloric acid aqueous ammonia C sodium hydroxide ethanoic acid D aqueous ammonia hydrochloric acid 13 Potassium cyanide, KCN, is a deadly poison that is famously used in many detective novels and period dramas. Which pair of reagents would you choose to prepare this salt? A potassium hydroxide and sodium cyanide B potassium nitrate and sodium cyanide C potassium hydroxide and hydrocyanic acid (HCN) D potassium nitrate and hydrocyanic acid (HCN) volume of X/ cm3

2018 Mid-Year Examination Secondary Three IP Chemistry 6 Nanyang Girls’ High School Setter: KXY, NHK, CT 14 How many atoms are present in 20 cm3 of ammonia gas at room temperature and pressure? A 2024×1000×6.02×10!" B 2024×1000×4×6.02×10!" C 206.02×10!"×4×24000 D 201000×4×24×6.02×10!" 15 A solution of sulfuric acid with a concentration of 2x mol dm–3 is titrated with potassium hydroxide solution with a concentration of 3x mol dm–3. If V cm3 of sulfuric acid was used, what is the volume of potassium hydroxide solution required? A !! V cm3 B !! V cm3 C !! V cm3 D !! V cm3 16 Phenol red is a pH indicator that can be used in acid-base titrations. It has the molecular formula of C19H14O5S. What is the relative molecular mass of phenol red? A 168.0 B 184.0 C 322.0 D 354.1 17 0.300 g of magnesium was added to 30.0 cm3 of 0.5 mol dm–3 of hydrochloric acid. It was then filtered and the filtrate crystallised, washed and dried. The mass of anhydrous salt formed were 0.682 g. What is the percentage yield of magnesium chloride formed? A 47.7% B 58.0% C 92.4% D 95.4%

2018 Mid-Year Examination Secondary Three IP Chemistry 7 Nanyang Girls’ High School Setter: KXY, NHK, CT [Turn Over] Refer to the following for question 18 and 19 Nitrogen triiodide, NI3, is a substance that sublimes at –20 °C and spontaneously decomposes at 0 °C into nitrogen and iodine vapours. It is so explosive that all it takes for it to detonate is the touch of a feather. 2NI3(s) à N2(g) + 3I2(g) 18 0.5 g of nitrogen triiodide was synthesised. How many moles of nitrogen triiodide was formed? A 381 B 3.47 x 10–3 C 1.27 x 10–3 D 3.55 x 10–3 19 Given that the molar volume of gases at 0 °C is 22.4 dm3 mol–1, what is the mass of nitrogen triiodide needed to produce 1 dm3 of gases from the decomposition reaction at 0 °C? A 8.22 g B 8.81 g C 16.4 g D 17.6 g 20 To prepare aluminium sulfate, Alex added 0.8 g of aluminium metal to excess sulfuric acid. 1000 cm3