2 The table shows the masses of some of the ions in 1000 cm3 of fruit juice. name of ion formula of ion mass of ion in 1000 cm3 of fruit juice / mg NH4 + 43 calcium Ca2+ 79 chloride Cl – 135 lithium Li+ 1 magnesium Mg2+ 80 nitrate NO3 – 35 phosphate PO4 3– 120 potassium K+ 575 sodium Na+ 120 SO4 2– 105 (a) Answer these questions using only the information in the table. (i) State which negative ion has the highest mass in 1000 cm3 of fruit juice. … [1] (ii) Give the formulae of the ions in ammonium sulfate. … and … [1] (iii) Calculate the mass of sodium ions in 200 cm3 of fruit juice. mass = … mg [1] (b) Describe a test for lithium ions. test … observations … [2] (c) Ions of the element potassium, K, are present in most fertilisers. State the names of two other elements that are in most fertilisers. 1 … 2 … [2] (d) Orange juice is acidic. Draw a circle around the pH of orange juice. pH 4 pH 7 pH 10 pH 13 [1] (e) Some soils are acidic. Give the names of two compounds that are used to make soils less acidic. 1 … 2 … [2] (f) Hydrogen chloride is an acidic gas produced when concentrated hydrochloric acid evaporates. (i) Describe the arrangement and separation of the molecules in hydrogen chloride gas. arrangement … … separation … … [2] (ii) A long glass tube is set up as shown. long glass tube cotton wool soaked in concentrated hydrochloric acid damp blue litmus paper At first, the blue litmus paper does not turn red. After a short time, the litmus paper turns red. Explain these observations using the kinetic particle model. … … … … … [3] [Total: 15]

2(a)(i) Cl – / chloride 1 2(a)(ii) NH4+ AND SO42- 1 2(a)(iii) 24 (mg) 1 2(b) flame test / description of flame test (1) (flame coloured) red (1) 2 2(c) nitrogen (1) phosphorus (1) 2 pH 4 circled 1 2(e) 1 mark each for any 2 of: • calcium carbonate • calcium oxide • calcium hydroxide 2 2(f)(i) arrangement: random (arrangement) / no fixed arrangement / no pattern / no fixed position (1) separation: far apart / far away (from each other) / distant (from each other) (1) 2 2(f)(ii) 1 mark each for any 3 of: • (HCl) molecules escape from solution • diffusion • molecules in (constant) movement / molecules collide / molecules travel • (movement of) molecules is random / haphazard / in every direction • molecules spread out / molecules mix • (molecules spread) from high(er) concentration to low(er) concentration • molecules hit the litmus paper / molecules 3 (a) To earn marks, you must identify the correct negative ion, provide both correct ion formulae, and calculate the correct mass of sodium ions. (b) To earn marks, you must describe a flame test and state that the observation is a red flame. (c) To earn marks, you must state nitrogen and phosphorus as the two other elements.

2 The table shows the masses of some of the ions in 1000 cm3 of fruit juice. name of ion formula of ion mass of ion in 1000 cm3 of fruit juice / mg ammonium NH4 + 15 Ca2+ 71 chloride Cl – 135 magnesium Mg2+ 160 nitrate NO3 – 2 phosphate PO4 3– 63 potassium K+ 184 sodium Na+ 3 SO4 2– 85 (a) Answer these questions using only the information in the table. (i) State which positive ion has the lowest mass in 1000 cm3 of fruit juice. … [1] (ii) Give the formulae of the ions in calcium sulfate. … and … [1] (iii) Calculate the mass of magnesium ions in 250 cm3 of fruit juice. mass = … mg [1] (b) Describe a test for calcium ions. test … observations … [2] (c) Ammonium ions, NH4 +, are present in most fertilisers. Ammonium ions contain nitrogen. Name two other elements present in most fertilisers. 1 … 2 … [2] (d) A student heated a mixture of ammonium chloride and sodium hydroxide in a test‑tube. NH4Cl + NaOH → NH3 + NaCl + H2O mixture of ammonium chloride and sodium hydroxide heat Pungent-smelling ammonia gas is given off. Describe one other observation that can be made. … [1] (e) Ammonia reacts with chlorine. Complete the equation for this reaction. …NH3 + …Cl 2 → N2 + 6HCl [2] (f) A small beaker of aqueous ammonia is placed at the front of a classroom. At first, the students at the back of the class do not smell the ammonia gas. After a short time, the students at the back of the class smell the ammonia. Explain these observations using the kinetic particle model. … … … … … [3] [Total: 13]

2(a)(i) Na + / sodium 1 2(a)(ii) Ca2+ AND SO42- 1 2(a)(iii) 40 (mg) 1 2(b) (add aqueous) sodium hydroxide (1) white precipitate (1) OR ( add aqueous) ammonia (1) no precipitate / very slight white precipitate (1) 2 2(c) potassium (1) phosphorus (1) 2 2(d) colourless liquid (condenses at the mouth of the tube) 1 2(e) 2 (NH3) (1) 3 (Cl2) (1) 2 2(f) 1 mark each for any 3 of: • evaporation of ammonia molecules (from the solution) / (ammonia) molecules escape from solution • diffusion • molecules in (constant) movement / molecules collide / molecules travel • (movement of) molecules is random / in every direction / haphazard • molecules spread out / molecules mix • (smell occurs when) molecules hit (the sensory cells in) the nose • (molecules spread) from higher concentration to lower concentration 3 To earn marks, you must correctly identify the positive ion with the lowest mass and provide the correct formulae for calcium and sulfate ions in part (a). For part (a)(iii), calculate the mass of magnesium ions in 250 cm3. In part (b), describe a valid test for calcium ions (e.g., adding sodium hydroxide or ammonia) and state the correct observation. For part (c), name two other elements found in most fertilisers besides nitrogen.

2 The table shows the masses of some of the ions in 1000 cm3 of fruit juice. name of ion formula of ion mass of ion in 1000 cm3 of fruit juice / mg ammonium NH4 + 6 calcium Ca2+ 73 chloride Cl – 238 magnesium Mg2+ 77 NO3 – 10 phosphate PO4 3– 20 potassium K+ 419 Na+ 3 sulfate SO4 2– 10 (a) Answer these questions using only the information in the table. (i) State which negative ion has the highest mass in 1000 cm3 of fruit juice. … [1] (ii) Give the formulae of the ions in sodium nitrate. … and … [1] (iii) Calculate the mass of ammonium ions in 250 cm3 of fruit juice. mass = … mg [1] (b) Describe a test for chloride ions. test … observations … [2] (c) Phosphate ions, PO4 3–, are present in most fertilisers. Phosphate ions contain phosphorus. (i) State the names of two other elements that are in most fertilisers. 1 … 2 … [2] (ii) Explain why farmers put fertilisers on fields where crops are to be grown. … … [1] (d) A student heated ammonium sulfate with sodium hydroxide in a test-tube. (i) Complete the equation for this reaction. (NH4)2SO4 + …NaOH → …NH3 + Na2SO4 + 2H2O [2] (ii) Concentrated aqueous ammonia releases fumes of ammonia gas. A long glass tube is set up as shown. long glass tube cotton wool soaked in concentrated aqueous ammonia damp red litmus paper At first, the red litmus paper does not turn blue. After a short time, the litmus paper turns blue. Explain these observations using the kinetic particle model. … … … … … [3] [Total: 13]

2(a)(i) Cl – / chloride 1 2(a)(ii) Na+ AND NO3– 1 2(a)(iii) 1.5 (mg) 1 2(b) add (aqueous acidified) silver nitrate (1) white precipitate / white solid (1) 2 2(c)(i) potassium (1) nitrogen (1) 2 2(c)(ii) to improve crop yield / to replace nitrogen (or other elements) lost from soil (by being absorbed by plants) / to replace nitrogen (or other elements) absorbed by plants 1 2(d)(i) 2 (NaOH) (1) 2 (NH3) (1) 2 2(d)(ii) 1 mark each for any 3 of: • (NH3) molecules escape from solution • diffusion • molecules in (constant) movement / molecules collide / molecules travel • (movement of) molecules is random / haphazard / in every direction • molecules spread out / molecules mix • (molecules spread) from high(er) concentration to low(er) concentration • molecules hit the litmus paper / molecules 3 (a) To earn marks, you must correctly identify the negative ion with the highest mass, provide the correct formulae for the ions in sodium nitrate, and calculate the correct mass of ammonium ions in 250 cm³ of fruit juice. (b) To earn marks, you must describe adding acidified silver nitrate solution and state that a white precipitate is observed. (c) To earn marks, you must name two other elements found in most fertilisers and explain why fertilisers are used.

3 The table shows some properties of four halogens. element melting point in °C boiling point in °C density of liquid at melting point in g / cm3 fluorine –220 –188 chlorine –101 1.56 bromine –7 59 3.12 iodine 114 184 4.93 (a) (i) Complete the table by predicting: ● the boiling point of chlorine ● the density of fluorine at its melting point. [2] (ii) Describe the trend in the melting points of the halogens down the group. … [1] (iii) Deduce the physical state of iodine at 130 °C. Explain your answer. … … … [2] (b) (i) Give the electronic structure of a fluorine atom. … [1] (ii) Explain why a fluoride ion has a single negative charge. … … [1] (c) Magnesium reacts with excess fluorine to produce magnesium fluoride. When 2.40 g of magnesium is reacted, 6.20 g of magnesium fluoride is produced. Calculate the mass of magnesium needed to produce 1.24 g of magnesium fluoride. mass of magnesium = … g [1] [Total: 8]

3(a)(i) boiling point of chlorine: any values between –100 and 10 (°C) (inclusive of these values) (1) density of fluorine: any values between 0.20 and 1.55 (g / cm3) (inclusive of these values) (1) 2 3(a)(ii) increases 1 3(a)(iii) liquid (1) 130 (°C) is between the melting and boiling point / the melting point is lower than 130 (°C) AND the boiling point is above 130 (°C) (1) 2 3(b)(i) 2,7 1 3(b)(ii) the number of electrons is one more than the number of protons / it has 9 protons and 10 electrons (1) 1 3(c) 0.48(0) (g) 1 To earn marks, you must predict reasonable values for the boiling point of chlorine and the density of fluorine based on trends, state that the melting points increase down the group, correctly identify iodine as a liquid at 130°C and explain why by referencing its melting and boiling points, give the correct electronic structure for fluorine, and explain the fluoride ion's charge by comparing its electron and proton count.

Cambridge IGCSE Chemistry · 0620

IGCSE Chemistry (0620) States of matter past paper questions

These questions cover the particle model, changes of state, and diffusion — the foundation the rest of the course builds on.

255 free questions from 2016–2021, each with its marking scheme. Open the full topical bank to filter by subtopic, paper, and year.

States of matter in IGCSE Chemistry 0620 exams, 2020–2025

Across 2020–2025, States of matter accounted for 273 questions worth 1,450 marks in Cambridge IGCSE Chemistry (0620) papers.

By year
Year	Questions	Marks
2020	40	224
2021	43	278
2022	47	270
2023	38	205
2024	53	261
2025	52	212

Most-tested subtopics

1.1 Solids, liquids and gases1171 marks
1.2 Diffusion211 marks

Appears in

Paper 1 · 75 qs
Paper 2 · 80 qs
Paper 3 · 75 qs
Paper 4 · 32 qs
Paper 6 · 11 qs

All most-tested Chemistry topics

2021 May/Jun · Paper 3 · Q2 · 15 marks
Marking scheme
Get Steven’s plain-English explanation
2021 May/Jun · Paper 3 · Q2 · 13 marks
Marking scheme
Get Steven’s plain-English explanation
2021 May/Jun · Paper 3 · Q2 · 13 marks
Marking scheme
Get Steven’s plain-English explanation
2021 Feb/Mar · Paper 3 · Q3 · 8 marks
Marking scheme
Get Steven’s plain-English explanation
2021 Feb/Mar · Paper 1 · Q1 · 1 mark
Marking scheme
Mark scheme — 2021 Paper 1 Q1
Answer: D
Get Steven’s plain-English explanation