What Do You Know About Acids And Bases?
Acids and alkalis are incredibly important for manufacturing, and for everyday life. Some examples of things made using acids and alkalis are soaps and detergents, fertilisers, car batteries and medicines - you will have probably learnt a lot more examples during your lessons, as well as the properties of acids and alkalis.
- 1.
What is an acid?
- A.
A substance that will neutralise an acid
- B.
A substance that produces H+ ions when added to water
- C.
A soluble base
- D.
A chemical which changes colour when added to acids and alkalis
Correct Answer
B. A substance that produces H+ ions when added to waterExplanation
The correct answer is "A substance that produces H+ ions when added to water". This is because acids are known to release hydrogen ions (H+) when dissolved in water, which is why they are also referred to as proton donors. This characteristic of acids is what gives them their acidic properties, such as the ability to corrode metals and react with bases to form salts.Rate this question:
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- 2.
What is an alkali?
- A.
A substance that will neutralise an acid
- B.
A substance that produces H+ ions when added to water
- C.
A soluble base
- D.
A chemical which changes colour when added to acids and alkalis
Correct Answer
C. A soluble baseExplanation
An alkali is a substance that is soluble in water and can neutralize an acid. It is a type of base that produces OH- ions when dissolved in water. This allows it to react with acidic substances, forming water and a salt. Therefore, an alkali is a soluble base that can neutralize acids.Rate this question:
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- 3.
A substance with a pH of 6 is...
- A.
A weak acid
- B.
A strong acid
- C.
A weak alkali
- D.
Neutral
Correct Answer
A. A weak acidExplanation
A substance with a pH of 6 is considered a weak acid because it is slightly acidic. pH values range from 0 to 14, with 7 being neutral. Anything below 7 is considered acidic, and the lower the pH value, the stronger the acid. Since a pH of 6 is only slightly acidic, it is classified as a weak acid.Rate this question:
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- 4.
Pick the correct equation for the reaction between hydrochloric acid and iron oxide.
- A.
Hydrochloric acid + solid iron (III) oxide → iron (III) chloride solution + water
- B.
Hydrochloric acid + iron (III) oxide → iron (II) chloride solution + water
- C.
Hydrochloric acid + iron (III) oxide → iron (III) chlorate solution + water
- D.
Sulfuric acid + iron (III) oxide → iron (III) chloride solution + water
Correct Answer
A. Hydrochloric acid + solid iron (III) oxide → iron (III) chloride solution + waterExplanation
The correct equation for the reaction between hydrochloric acid and iron (III) oxide is Hydrochloric acid + solid iron (III) oxide → iron (III) chloride solution + water. This is because hydrochloric acid reacts with iron (III) oxide to form iron (III) chloride and water. The Roman numeral III in parentheses indicates the oxidation state of iron in the compound.Rate this question:
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- 5.
We can react an acid and an alkali together to produce a salt. The correct name for this type of chemical reaction is...
- A.
Combustion
- B.
Oxidation
- C.
Thermal decomposition
- D.
Neutralisation
Correct Answer
D. NeutralisationExplanation
Neutralisation is the correct name for the chemical reaction that occurs when an acid and an alkali are combined to produce a salt. During this reaction, the acid donates a hydrogen ion (H+) to the alkali, which accepts it to form water. The remaining ions from the acid and alkali combine to form a salt. This reaction is called neutralisation because it results in the formation of a neutral substance, water, from the combination of an acid and an alkali.Rate this question:
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- 6.
When an acid and an alkali react, a salt and water are formed. Pick the correct salt produced when ammonium hydroxide reacts with nitric acid.
- A.
Ammonium chloride
- B.
Ammonium nitrate
- C.
Ammonium sulfate
- D.
Ammonium phosphate
Correct Answer
B. Ammonium nitrateExplanation
When ammonium hydroxide (NH4OH) reacts with nitric acid (HNO3), the salt produced is ammonium nitrate (NH4NO3). This is because the ammonium ion (NH4+) from ammonium hydroxide combines with the nitrate ion (NO3-) from nitric acid to form the salt ammonium nitrate.Rate this question:
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- 7.
Salts can also be made by reacting metals with acids. What gas is given off when a metal reacts with an acid?
- A.
Oxygen
- B.
Carbon dioxide
- C.
Hydrogen
- D.
Nitrogen
Correct Answer
C. HydrogenExplanation
When a metal reacts with an acid, the gas given off is hydrogen. This is because metals are more reactive than hydrogen, so they displace hydrogen from the acid. The reaction between a metal and an acid results in the formation of a salt and the release of hydrogen gas.Rate this question:
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- 8.
Precipitation reactions occur when an insoluble salt is formed. Precipitation reactions can be used in industry to...
- A.
Remove some substances from waste water
- B.
Split large molecules into smaller ones
- C.
Remove unwanted impurities from metals
- D.
Remove metals from their ores
Correct Answer
A. Remove some substances from waste waterExplanation
Precipitation reactions occur when an insoluble salt is formed. In the context of waste water treatment, precipitation reactions can be used to remove some substances from the water. This is achieved by adding a specific reagent that reacts with the substances in the water, forming insoluble salts. These insoluble salts then precipitate out of the water, allowing for their easy removal. This process helps to purify the waste water by removing harmful or unwanted substances, making it safer for disposal or reuse.Rate this question:
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- 9.
A strong acid...
- A.
Turns universal indicator paper green
- B.
Has a high pH number
- C.
Is partially ionised in water
- D.
Is 100% ionised in water
Correct Answer
D. Is 100% ionised in waterExplanation
A strong acid is 100% ionized in water because it completely dissociates into ions when dissolved in water. This means that all of the acid molecules break apart into their constituent ions, which allows them to conduct electricity and exhibit strong acidic properties. This is in contrast to a weak acid, which only partially ionizes in water and does not completely dissociate into ions. Therefore, the answer "is 100% ionized in water" is the correct explanation for a strong acid.Rate this question:
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- 10.
Pick the correct combination of definitions.
- A.
Acid - proton acceptor Alkali - proton donor
- B.
Acid - proton donor Alkali - proton acceptor
- C.
Acid - proton giver Alkali - proton donor
- D.
Acid - proton acceptor Alkali - proton acceptor
Correct Answer
B. Acid - proton donor Alkali - proton acceptorExplanation
In chemistry, an acid is a substance that donates protons (H+) during a chemical reaction. It increases the concentration of H+ ions in a solution. On the other hand, an alkali is a substance that accepts protons (H+) during a chemical reaction. It decreases the concentration of H+ ions in a solution. Therefore, the correct combination of definitions is "Acid - proton donor" and "Alkali - proton acceptor".Rate this question:
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