Acids in the kitchen

Tests: 6 of 11 right · Exam: 1 of 4 right · Kind: plain · Understood: 12 of 15 · Run: 2026-10-18, commit f3c23ea72

Lesson 15 of the chemistry course of Mova's primary school, as Mova's small model took its tests: it had read this lesson and the ones before it and learned from their exercises. Each test shows the options in the order the student saw them, its choice, the right answer, the score of every option and why it chose. The lesson itself, sentence by sentence with trees and pragmatics: the lesson in the corpora.

Every question of this lesson and each of its options parsed by Mova, with trees and pragmatics: the lesson's questions in the corpora.

Test 1 · right ✓

Sophie licks a sour sweet and it stings her tongue. Why?

1. It is dusted with acid powder — ← Mova's choice · ✓ the right answer · score 6
2. It is far too cold for her tongue — no support
3. It has tiny bits of glass on it — no support
4. It is covered in salt crystals — no support

Why: It took the question to ask why something happens (its cause). It chose option 1 with score 6, the only option with support. Its support: lesson 15, line 5: «Sour tastes come from acids; lemons contain citric acid, and sour sweets are dusted with acid powder that stings the tongue.», reached through the same lesson line as the sentence the question matched. What matched: the same action «dust» (+2); the same thing acted on «sour sweets» (+2); the same circumstance (+2). · the question and its options parsed, with trees and pragmatics

Test 2 · right ✓

"stomach acid is strong, so why isn't there a hole in me?" What's the answer?

1. The acid is used up on food before it ever touches the wall — no support
2. Stomach acid is actually just warm water — no support
3. A layer of mucus protects the stomach wall — ← Mova's choice · ✓ the right answer · score 6
4. The stomach is lined with metal — no support

Why: It took the question to ask why something happens (its cause). It chose option 3 with score 6, the only option with support. Its support: lesson 15, line 11: «The stomach makes a strong acid that helps digest food and kills germs; a layer of mucus protects the stomach wall.», reached through the same lesson line as the sentence the question matched. What matched: the same action «protect» (+2); the same doer «layer» (+2); the same thing acted on «stomach wall» (+2). · the question and its options parsed, with trees and pragmatics

Test 3 · right ✓

Harry: "dock leaves are a proper chemical cure for nettles, they cancel the acid". What's true?

1. Yes, they pull the stinging hairs out — no support
2. No, they make the sting much worse — no support
3. They help mostly by rubbing and cooling — ← Mova's choice · ✓ the right answer · score 10
4. Yes, they neutralise the acid — no support

Why: It took the question to ask which statement is true. It chose option 3 with score 10, the only option with support. Its support: lesson 15, line 14: «Dock leaves on nettle stings help mostly because rubbing and coolness soothe; they are not a strong chemical cure.», reached through the remembered sentence the question matched. What matched: the same action «help» (+4); the same doer «dock leaves» (+4); the same property (+2). · the question and its options parsed, with trees and pragmatics

Test 4 · right ✓

If you left milk with a squeeze of lemon on a warm stove, what would you get?

1. Lumps that can make simple soft cheese — ← Mova's choice · ✓ the right answer · score 12
2. Clear sweet lemonade — no support
3. Milk that turns bright blue — no support
4. Butter floating on the top — no support

Why: It took the question to ask what it is done to. It chose option 1 with score 12, the only option with support. Its support: lesson 15, line 3: «Squeeze lemon into warm milk and it suddenly forms lumps: the acid makes the milk's proteins clump together. Cheese-makers use exactly this trick to make soft…», reached through the same lesson line as the sentence the question matched. What matched: it fills the role the question asks for (+5); the same thing acted on «soft cheeses» (+4); the same action «make» (+3). · the question and its options parsed, with trees and pragmatics

Test 5 · right ✓

"dad's car battery is dead, can i open it and see?" What should the answer be?

1. No, because the battery will get cold — no support
2. Yes, as long as you wear a thick winter coat and gloves — no support
3. No, it holds strong acid that burns skin and eyes — ← Mova's choice · ✓ the right answer · score 14
4. Yes, it's only weak lemon acid — score 4

Why: It took the question to ask what it is done to. It chose option 3 with score 14, against 4 for the next best. Its support: lesson 15, line 4: «Strong acids are a different story. Your stomach makes a strong acid to digest food and kill germs, and a car battery holds a strong acid that can burn skin an…», reached through the same lesson line as the sentence the question matched. What matched: it fills the role the question asks for (+5); the same thing acted on «skin» (+4); the same action «burn» (+3); the same doer «strong acid» (+2). · the question and its options parsed, with trees and pragmatics

Test 6 · wrong ✗

Why are some old stone statues losing their faces?

1. Birds pecked their faces off — ← Mova's choice · no support
2. Acid rain slowly ate away the stone — ✓ the right answer · no support
3. People kept rubbing them for luck — no support
4. The stone slowly melted away in the hot summers — no support

Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics

Test 7 · wrong ✗

Ava says all acids are dangerous and you should never eat one. What's true?

1. She is right, all acids burn the skin — ← Mova's choice · score 12
2. Many foods contain weak acids that are safe — ✓ the right answer · score 5
3. Only the acids in sweets are safe to eat — no support
4. Acids are found only in factories — no support

Why: It took the question to ask which statement is true. It chose option 1 with score 12, against 5 for the next best. Its support: lesson 15, line 16: «Car batteries contain a strong acid that burns skin and eyes, so they must never be opened.», reached through the remembered sentence the question matched. What matched: the same action «burn» (+4); the same doer «strong acid» (+4); the same thing acted on «skin» (+4). The right option, 2, scored 5. · the question and its options parsed, with trees and pragmatics

Test 8 · right ✓

In a cartoon, a hero drinks car-battery acid "for energy". What's wrong with that?

1. Nothing, battery acid is just like a sharp lemonade — no support
2. It would only taste a little sour — no support
3. Strong acid would badly burn the mouth and throat — ← Mova's choice · ✓ the right answer · score 4
4. It would make him glow in the dark — no support

Why: It took the question to ask which statement is true. It chose option 3 with score 4, the only option with support. Its support: lesson 15, line 4: «Strong acids are a different story. Your stomach makes a strong acid to digest food and kill germs, and a car battery holds a strong acid that can burn skin an…», reached through the same lesson line as the sentence the question matched. What matched: the same action «burn» (+3); the same doer «strong acid» (+2). Against it: a different thing acted on (counts against) (-1). · the question and its options parsed, with trees and pragmatics

Test 9 · wrong ✗

Which tastes most sour?

1. A spoonful of plain rice — ← Mova's choice · score 8
2. A slice of white bread — no support
3. An unripe green plum — ✓ the right answer · score 8
4. A ripe, sweet yellow banana — score 8

Why: It took the question to ask who or what does it. It chose option 1 with score 8, tied with another option at 8 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 15, line 2: «Acids are a big family of substances that taste sour and react with many things. Weak acids are all over the kitchen: vinegar on your chips, the tang of yoghur…», reached through the remembered sentence the question matched. What matched: the same action «taste» (+4); the same property (+4). The right option, 3, scored 8. · the question and its options parsed, with trees and pragmatics

Test 10 · wrong ✗

"why's my curry stinging the ulcer in my mouth? there's tomato in it". What's going on?

1. Tomatoes are full of hot chilli — no support
2. Acidic food like tomato makes a mouth sore sting — ✓ the right answer · no support
3. The curry is too salty for the sore — no support
4. Curry contains formic acid from the ants in the spices — ← Mova's choice · score 3

Why: It took the question to ask who or what does it. It chose option 4 with score 3, the only option with support. Its support: lesson 15, line 5: «Sour tastes come from acids; lemons contain citric acid, and sour sweets are dusted with acid powder that stings the tongue.», reached through the same lesson line as the sentence the question matched. What matched: the same action «contain» (+2); the same thing acted on «citric acid» (+2). Against it: a different doer (counts against) (-1). The right option, 2, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 11 · wrong ✗

Nan: "vinegar's made from wine". Teen: "lol no it's from lemons". Who's closer?

1. Neither: vinegar comes from the sea — ← Mova's choice · no support
2. Nan: bacteria make vinegar from wine or cider — ✓ the right answer · no support
3. Both: it is lemon juice and wine mixed together — no support
4. The teen: vinegar is lemon juice — no support

Why: No option found support in what it remembers, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics

Exam question 1 · formal language · wrong ✗

Identify the substance principally responsible for the sour taste of the lemon.

1. Acetic acid — ← Mova's choice · score 6
2. Formic acid — no support
3. Lactic acid — no support
4. Citric acid — ✓ the right answer · score 4

Why: It took the question to ask which statement is true. It chose option 1 with score 6, against 4 for the next best. Its support: lesson 15, line 7: «Vinegar is water with acetic acid in it, made by bacteria from wine or cider.», reached through the remembered sentence the question matched. What matched: the same circumstance (+4); the same property (+2). The right option, 4, scored 4. · the question and its options parsed, with trees and pragmatics

Exam question 2 · formal language · wrong ✗

It is given that pickled vegetables remain edible for several months when stored in vinegar. Ascertain the principal reason.

1. The vinegar forms an airtight layer of fat — score 1
2. The vinegar maintains a very low temperature — no support
3. The vinegar removes all the water from the vegetables — ← Mova's choice · score 3
4. The acidity prevents the growth of most germs — ✓ the right answer · score 1

Why: It took the question to ask which statement is true. It chose option 3 with score 3, against 1 for the next best. Its support: lesson 15, line 7: «Vinegar is water with acetic acid in it, made by bacteria from wine or cider.», reached through the option's own match among the sentences about the question's things. What matched: the same thing acted on «water» (+2); the same doer «vinegar» (+1). The right option, 4, scored 1. · the question and its options parsed, with trees and pragmatics

Exam question 3 · formal language · right ✓

Which of the following statements most accurately characterises the protection of the stomach against its own acid?

1. The stomach wall is protected by a layer of mucus — ← Mova's choice · ✓ the right answer · score 14
2. The stomach is lined with a thin layer of bone — no support
3. The stomach acid is too weak to harm tissue — score 5
4. The acid is produced exclusively during sleep — score 4

Why: It took the question to ask who or what does it. It chose option 1 with score 14, against 5 for the next best. Its support: lesson 15, line 11: «The stomach makes a strong acid that helps digest food and kills germs; a layer of mucus protects the stomach wall.», reached through the remembered sentence the question matched. What matched: the same action «protect» (+4); the same thing acted on «stomach wall» (+4); it fills the role the question asks for (+4); the same doer «layer» (+2). · the question and its options parsed, with trees and pragmatics

Exam question 4 · formal language · wrong ✗

Select the response consistent with the established facts concerning acid rain.

1. It is caused by salt evaporating from the oceans — ← Mova's choice · no support
2. It grew greatly once factories became cleaner — no support
3. It is produced by citrus fruit grown near clouds — no support
4. It forms when gases from smoke dissolve in raindrops — ✓ the right answer · no support

Why: Nothing it remembers matched the question, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics

This page in Markdown → https://md.mova.elamur.ai/free/en/school-run/chemistry/15-acids-in-the-kitchen/