Acids Flashcards
What is an indicator?
It is a substance that changes colour to tell you if something is acid, alkali or neutral
What colour does litmus go in acids, alkalis and neutral solutions
Red = Acid
Blue = Alkali
Pink = Neutral
What does universal indicator do?
Universal indicator changes colour in an acid, an alkali or a neutral solution to tell us how strong the acid or alkali is.
The colour the universal indicator changes to tells us the strength of the acid or alkali on the pH scale
What is the pH scale?
The pH scale tells us how strong or weak an acid is
A pH of 0 is a strong acid, a pH of 14 is a strong alkali. A pH of 7 is neutral
What does this symbol mean?
Explosive
What does this symbol mean?
Flammable
What does this symbol mean?
Corrosive
What does this symbol mean?
Toxic
What does this symbol mean?
Irritant
What does this symbol mean?
Hazardous to the environment
What does the word ‘corrosive’ mean?
Which substances are corrosive?
Corrosive means that the substance will eat through your skin or other substances
Strong acids and strong alkalis are corrosive
What does the word irritant mean?
Which substances are irritant?
Irritant means it can make your skin red and itchy
Weak acids and weak alkalis are irritant
What is an acid
An acid is a substance that can corrode through different materials, including human skin.
What colour is a strong acid on universal indicator?
What pH is this?
A strong acid is red. It has a pH of 0.
What colour is a weak acid on universal indicator?
What pH is this?
A weak acid is yellow on universal indicator
It has a pH of 6
What colour is a neutral solution on universal indicator?
What pH is this?
A neutral solution is green on universal indicator
It has a pH of 7
What colour is a strong alkali on universal indicator?
What pH is this?
A strong alkali is purple on universal indicator
It has a pH of 14
What colour is a weak alkali on universal indicator?
What pH is this?
A weak alkali is light blue on universal indicator
It has a pH of 8
What is the difference between a wasp sting and a bee sting?
A wasp sting is an alkali and a bee sting is acidic
What does the word neutralisation mean?
What is the word equation for neutralisation?
Neutralisation is when an acid and an alkali cancel each other out
Word equation:
Acid + Alkali —> Salt + Water
What substances can be used to help a bee sting and why?
Weak alkalis such as bicarbonate of soda or toothpaste can be used to help a bee sting
This is becuase it neutralises the acid in a bee sting, but is not strong enough to corrode your skin
What substances can be used to help a wasp sting and why?
Weak alkalis such as lemon juice, tomato juice and vinegar can be used to help a wasp sting
This is becuase they are weak acids and neutralise the alkaline wasp sting without corroding your skin
What is the word equation for a reaction between an acid and a carbonate?
How do you test for this reaction?
acid + carbonate —> salt + carbon dioxide + water
To test for this reaction you bubble the gas created through limewater. If carbon dioxide is produced the limewater goes cloudy
Why are do limescale removers contain acid?
Limescale is a carbonate. The acid reacts with a carbonate turning it into a salt which can be washed away
What is the word equation between an acid and a metal?
How do we test for this?
The word equation between an acid and a metal is:
acid + metal —> salt + hydrogen
You test for the hydrogen with the squeaky pop test. You collect the gas produced in a test tube and put a splint lis splint in it. If hydrogen is created it goes pop.
What is acid rain?
What problems do acid rain cause and how is it created?
Acid rain is when the rain becomes a weak acid. This happens because of sulphur dioxide pollution from power stations
Acid rain can corrode limestone buildings and statues, corrode through metal such as cars and kill wildlife such as forests and fish.
