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P4 General Studies: States of Matter and Dissolving (Paper 3 (challenge))
Tutor Prep Guide · the three states of matter, dissolving with solutes and solvents, factors that change dissolving speed, saturated solutions and separation by filtering or evaporation
P4 General Studies: States of Matter and Dissolving (Paper 3 (challenge))
Paper three is mostly two-step work, plus the two tricky ideas of saturation and surface area.
Direct answers Separate how much dissolves from how fast it dissolves before calculating.
01 Paper details (check answers afterwards)
| Item | Detail |
|---|---|
| Questions | 10 |
| Suggested time | 20 |
| Difficulty mix | Foundation 3 · Intermediate 3 · Challenge 3 · Error redo 1 |
| Chapter | Chapter: P4 General Studies: States of Matter and Dissolving |
| Level | parts of a closed circuit, conductors against insulators, series against parallel, adding up battery voltage, and electrical safety |
02 Questions (10 items)
- FoundationWater is heated from 25 to 85 degrees Celsius. How much does the temperature rise?
- FoundationSteam cools and forms droplets. What is this change called?
- FoundationFive hundred grams of ice melts completely. What is the mass of the water?
- IntermediateForty grams of sugar dissolve in 160 g of water. What proportion of the solution is sugar, in percentage points?
- IntermediateEvaporating 250 g of salt water leaves 20 g of salt. What proportion of the original solution was water, in percentage points?
- IntermediateEighteen grams of sugar dissolve in six minutes. What is the average per minute?
- ChallengeTwo cups hold the same water at the same temperature; one gets 5 g of castor sugar and the other a 5 g lump. Which dissolves faster?
- ChallengeAt 20 degrees Celsius 100 g of water dissolves at most 36 g of salt. If 40 g is added, how much stays undissolved?
- ChallengeSalt water loses 60 mL in two days. At that rate, how many days are needed to lose 150 mL?
- Error redoError clinic: a gas has no mass and takes up no space. Is that right?
03 Answers and one-line notes
| # | Answer | One-line note |
|---|---|---|
| 1 | 60 degrees Celsius. | Eighty-five minus 25 gives a rise of 60 degrees. |
| 2 | Condensation. | Gas turning to liquid is condensation; droplets on a cold drink come from water vapour in the air. |
| 3 | 500 g. | A change of state does not change mass, so it is still 500 g. |
| 4 | 20.0 percentage points. | The solution is 200 g in total; 40 divided by 200 then multiplied by 100 gives 20.0 percentage points. |
| 5 | 92.0 percentage points. | The water is 230 g; 230 divided by 250 then multiplied by 100 gives 92.0 percentage points. |
| 6 | 3.0 g. | Eighteen divided by six gives 3.0 g a minute. |
| 7 | The one with castor sugar. | Castor sugar has more surface area in contact with water, so it dissolves faster, though both can end up dissolving the same total. |
| 8 | 4 g. | Forty minus 36 leaves 4 g at the bottom, giving a saturated solution. |
| 9 | 5.0 days. | That is 30.0 mL a day, and 150 divided by 30.0 gives 5.0 days. |
| 10 | No. | A gas has mass and occupies space; its particles are just far apart and easy to compress. |
04 What to do after marking
- After marking, redo only the wrong items and write down which step went wrong (formula, unit, or misread number).
- Repeat the same item two days later; move to the next paper only when both attempts are correct.
- Parents only need the answer and note columns; there is no need to explain every item.
Paper four clears the conductor, insulator and battery direction misconceptions.Tutor Registration →
Questions and answers are written originally by the TutorZone team and are not taken from any school, publisher or examination authority paper. Every value is checked by computer.