Topic 4 Acids And Bases Flashcards
What is a ph scale
A measure of how acidic or alkaline a solution is
What do acids form in water
Hydrogen ions
How is concentration affected by hydrogen ions
The more hydrogen ions the more concentrated the solution, the more acidic the solution so lower PH
What is a base
A substance that reacts with with an acid to produce salt and water
What is an alkali
A base that is soluble in water
What do alkalis form in water and
Hydroxide ions
What’s an indicator
A dye that changes colour depending on whether it’s above or below a certain pH
What colour does litmus go when acidic neutral and alkaline
Acidic - red
Neutral - purple
Alkaline - blue
What colour does methyl orange go when acidic neutral and alkaline
Acidic - red
Neutral and alkaline - yellow
What is the reaction between an acid and alkali called
Neutralisation
What does neutralisation produce
Salt and water
Where does neutralisation occur
In aqueous solution
What happens when an acid neutralises a base
The products are neutral with a ph of 7
When at pH 7 both the concentration of hydrogen and hydroxide ions is equal
