Year 8 Term 1 Flashcards
What is an acid ?
A substance that dissolves in water with a pH less than 7
Names common acids.
Hydrochloric acid, sulfuric acid, nitric acid, ethanoic acid, citric acid and carbonic acid.
What is an alkali ?
A substance that dissolves in water to give a solution with pH more than 7.
Name common alkalis.
Calcium hydroxide(lime), magnesium hydroxide, sodium hydroxide and ammonia.
What is an indicator ?
A substance which is one colour in an acidic solution and another in an alkaline solution.
Can indicators be made from natural coloured substances ?
Yes they can be made from natural coloured substance (red cabbage).
Name common lab indicators.
Methyl orange, bromothymol blue, phenolphthalein and litmus.
What is universal indicator ?
It is a mixture of different indicators that shows how strong an acid or alkali solution is.
What is a base ?
It’s an insoluble metal oxide or hydroxide.
What is an alkali ? (In terms of base)
A soluble base.
What does a base do ?
Reacts with an acid and neutralises it.
What is the reaction between an acid and base called ?
It’s called a nuetralisation.
What can a neutralisation reaction be followed by ?
An indicator
What is salt made in ?
Salt is made in a neutralisation reaction.
State common uses of neutralisation reactions.
Indigestion, bee stings (acidic), wasp stings (alkaline), nettle stings (acidic) and soil treatment.
What do acids need to work in an acidic fashion ?
Water.
What is the difference between concentrated and diluted acids ?
There is more acid in a concentrated acid than a diluted acid.
Are bee stings acidic or alkaline ?
Acidic
Are wasp stings acidic or alkaline ?
Alkaline
Are nettle stings acidic or alkaline ?
Acidic
What was the solid acid we dissolved ?
Citric acid
What’s the lowest pH value on the scale ?
pH 0
Where is hydrochloric acid found ?
A human stomach