Acids and Alkalis

Acids and Alkalis

by Karen Lewis

​Acids are compounds with replaceable hydrogen.

​

​hydrochloric acid   HCl  hydrogen chloride

​

sulphuric acid H2SO4  hydrogen sulphate

 

nitric acid HNO3   hydrogen nitrate

   

​Alkalis are compounds with replaceable hydroxide.

sodium hydroxide    NaOH 

calcium  hydroxide  Ca(OH)2 

​The reaction between an acid and an alkali is called neutralisation

Multiple Choice

Acids are compounds with replaceable...

• Hydrogen

• Oxygen

• Hydroxides

Multiple Choice

Alkalis are compounds with replaceable ......

• Hydrogen

• Oxygen

• Hydroxides

Multiple Choice

The reaction between and acid and an alkali is called.......

• Oxidation

• Neutralisation

• Reduction

Multiple Choice

select the acid that can be found in citrus fruits

• hydrochloric

• Nitric

• Citric

• Sulphuric

Multiple Choice

HCl is teh formula for........

• Sulphuric acid

• Nitric acid 

• Ethanoic acid

• Hydrochloric acid

Multiple Choice

H2SO4 is the formula for.....

• Ethanoic acid

• Sulphuric acid

• Hydrochloric acid

• Nitric acid

Multiple Choice

HNO3 is the formula for...

• Nitric acid

• sulphuric acid

• citric acid

• hydrochloric acid 

Multiple Choice

What do you call the reaction when an acid is added to an alkali?

• pH reaction

• Neutralisation reaction

• Addition reaction

• Oxidation reaction

Multiple Choice

What indicator would be best to use in a neutralisation reaction?

• Red litmus

• Blue litmus

• Universal indicator

• Red cabbage indicator

Multiple Choice

When something has been neutralised, what pH should it end up at?

• 1

• 14

• 7

• 8

Multiple Choice

What would be the best thing to use to neutralise sulphuric acid (pH 1)?

• Sodium Hydroxide (pH 14)

• Sodium Hydrogencarbonate (pH 8)

• Ethanoic Acid (pH 3)

• Water (pH 7)

Multiple Choice

Where in the body would you find hydrochloric acid, which may need to be neutralised if someone has heartburn?

• windpipe

• heart

• liver

• stomach

​Bases and alkalis

A base is a substance that can react with acids and neutralise them. Bases are usually:

• metal oxides, such as copper oxide

• metal hydroxides, such as sodium hydroxide, or

• metal carbonates, such as calcium carbonate

Many bases are insoluble - they do not dissolve in water. However, if a base does dissolve in water, we also call it an alkali

​

Bases in the laboratory

Household cleaning products contain strong bases, such as sodium hydroxide solution. Like acids, their bottles are labelled with a symbol to warn that they may make your skin red or blistered unless you wash off any spills with plenty of water.

​

Alkalis feel soapy when they get on your skin, so it is easy to tell when you have had an accident and must wash your hands.

Just like concentrated acids, concentrated alkalis are corrosive. They can attack metals and destroy skin if spilled, so their containers are labelled with a warning symbol. Concentrated alkalis are just as dangerous as concentrated acids, sometimes more dangerous

​Bases in the home

Bases react with oils and fats, so they are often used in household cleaners. For example, drain cleaners and oven cleaners usually contain sodium hydroxide. Ammonia is also commonly used in cleaners, and it can be recognised by its choking smell.

It is wise to wear gloves when using these substances, otherwise they will react with your skin and burn it.

Weak bases and alkalis are found in toothpaste, antacid tablets (to help cure an upset stomach) and baking powder.

Multiple Choice

What happens to litmus paper in acidic solutions?

• Red litmus turns blue

• Blue litmus turns red

• Yellow litmus turns green

Multiple Choice

Universal indicator solution is usually green to begin with. What does this mean?

• it os acidic

• it is alkaline

• it is neutral

Multiple Choice

A liquid has a pH of 8. What does this mean?

• It is weakly acidic

• It is weakly alkaline

• It is neutral

Multiple Choice

A liquid has a pH of 1. What does this mean?

• It must be sodium hydroxide solution

• It is strongly acidic

• It is weakly acidic

Multiple Choice

Which acid could be used to make ammonium nitrate (a type of fertiliser)?

• Hydrochloric acid

• Sulphuric acid

• Nitric acid

Multiple Choice

Farmers use lime to neutralise their acidic soils. What sort of substance is lime?

• A base

• An acid

• A sharp tasting drink

Multiple Choice

Which salt is made when copper oxide and sulphuric acid react together?

• Copper sulfate

• Copper sulphuroxide

• Copper sulphide

Multiple Choice

What products are formed when a metal oxide reacts with an acid?

• A salt only

• A salt and water

• A salt, water and carbon dioxide

Multiple Choice

What products are formed when a metal carbonate reacts with an acid?

• A salt only

• A salt and water

• A salt, water and carbon dioxide

Multiple Choice

What is the name of the salt made from nitric acid and potassium hydroxide?

• Potassium nitride

• Potassium nitrate

• Potassium nitric

Multiple Choice

What does this hazard symbol mean?

• corrosive

• irritant

• hatmful

• oxidising

Multiple Choice

Which of these acids is most likely to be dangerous?

• Citric acid

• Carbonic acid

• Hydrochloric acid

Multiple Choice

Which statement about alkalis is true?

• They are all bases

• They cannot neutralise acids

• They are all insoluble

Multiple Choice

Which statement about bases is true?

• They are all alkalis

• They can neutralise acids

• They are all soluble

Multiple Choice

Which of these is not a base?

• Copper oxide

• Sodium hydroxide

• Sulfur dioxide