Topic 4 Acids and bases Flashcards
What does a pH scale go from
1 - 14
What is the pH scale measure of
How acidic or alkaline solution
What does a low pH mean
The solution is acidic
What does ahigh pH mean
The solution is alkaline
What is a neutral pH
pH 7
What is an indicator
A dye that changes colour depending on whether it is above or below a certain PH

What are wide range indicators
A mixture of dies that means they gradually change colour of a broad range of pH e.g. universal indicator
What are wide range indicators useful for
Estimating the pH of a solution
Why is the universal indicator only an estimate
Colour is subjective
What is a pH probe attached to
A pH meter
What does a pH probe do
Measures pH electronically
How is the pH probe used
Placed in a solution you’re measuring at the pH is given on a digital display as a numerical value meaning it is more accurate than indicator
What do acids and bases do to each other
Neutralise each other
What is an acid
A substance that forms aqueous solutions with a pH of less than seven
Acids form H plus ions in water
What is a base
A substance with a pH greater than seven
What is an alkali
A base that dissolves in water to form a solution with a pH greater than seven
Phone 0H minus ions in water
What is the difference between alkaline and bases
Are both bases but only alkali dissolves in water
Neutralisation reaction between acid and bases
Acid + base -> salt + water
Neutralisation between acids and alkalis
H+ + OH- -> H2O
When an acid neutralise as a base what are the products
Neutral and have a pH of seven
What can the neutralisation of strong alkalis and acids be used for
Calculate the concentration of an acid or alkali by titration
