Every card in Acids and alkalis, Year 7: more practice
The whole deck, in order — so you can read it through before your child ever sees it.
- Which strong acid, made in the lining of your stomach, helps to break down the food you eat?
Hydrochloric acid
HintIt is kept, much weaker, in a bottle on the school lab bench.
WhyStomach acid is hydrochloric acid, strong enough to kill many germs in food. The stomach wall is coated in mucus so that it is not damaged by it.
- Oven cleaner and soap both feel slippery. Are they acids or alkalis?
Alkalis
HintAcids taste sharp; these substances do the opposite and are good at lifting grease.
WhyAlkalis feel slippery or soapy and dissolve grease, which is why cleaning products often contain them. Never taste or touch unknown substances to find out.
- Lemon juice and car-battery acid are both acids, yet you can drink only one of them. What is different about the dangerous one?
It is far more concentrated
HintThink about how much acid is packed into each litre of liquid.
WhyConcentration means how much of the substance is dissolved in a given volume. A little acid in a lot of water is harmless, but the same acid in concentrated form can burn skin.
- What colour does universal indicator turn in pure water, which is neutral? (one word)
Green
HintThis colour sits exactly halfway along the indicator colour chart.
WhyUniversal indicator runs from red for strong acids, through orange and yellow, to green for neutral, then blue to purple for strong alkalis.
- What colour does red litmus paper turn in an alkali?
Blue
HintAlkalis do the opposite of what acids do to litmus paper.
WhyRed litmus paper turns blue in alkalis, and blue litmus turns red in acids. In a neutral solution neither paper changes colour.
- Two clear, colourless liquids sit in unlabelled beakers. Why can you not tell which is the acid just by looking?
Acids and alkalis look the same, so you need an indicator to show the difference
HintThink about how the two liquids appear before anything is added.
WhyMany acids and alkalis look like plain water. An indicator is a dye that changes colour to show which one you have, so you do not need to taste or touch it.
- A bottle carries a symbol of a dead tree beside a dead fish. What does it warn about?
Danger to the environment
HintThe picture shows what the substance can harm if it is poured away carelessly.
WhyThis pictogram means the substance is hazardous to the environment, especially to water life. Such chemicals must be collected for disposal, not tipped down a sink.
- What must you keep well away from a flammable liquid?
Naked flames, sparks and heat
HintThink of the things that could set it alight.
WhyA flammable liquid gives off a vapour that catches fire easily. Bunsen burners are turned off or removed before such a liquid is used.
- Corrosive substances damage whatever they touch. What does a toxic substance do instead?
It poisons the body once it gets inside
HintCorrosives harm the surface; this warning is about what happens after it is swallowed or breathed in.
WhyCorrosive means it attacks skin, eyes or metal on contact. Toxic means it is poisonous if it enters the body by swallowing, breathing in or through the skin.
- A drop of a corrosive liquid lands on your skin. What should you do straight away?
Rinse it under cold running water and tell your teacher
HintDilute it as quickly as you can, and make sure an adult knows.
WhyPlenty of cold running water dilutes the chemical and washes it away. Telling the teacher means help arrives and the incident is recorded.
1★ KS3-CHEM-ACD-0025
2★ KS3-CHEM-ACD-0026
3★ KS3-CHEM-ACD-0027
4★ KS3-CHEM-ACD-0028
5★ KS3-CHEM-ACD-0029
6★ KS3-CHEM-ACD-0030
7★ KS3-CHEM-ACD-0031
8★ KS3-CHEM-ACD-0032
9★ KS3-CHEM-ACD-0033
10★ KS3-CHEM-ACD-0034
Keep what you learn
Here, nothing is saved. In your child’s own sky every card is scheduled — it comes back just before they’d forget it — and the professor who wrote it is one tap away.