Post on 26-Mar-2015
transcript
Do now!Can you spell the following
words CORRECTLY in your book?
Newtralisation, asid, alcali, litmas, indicater.
Last lesson
• Using Litmus as an indicator
Indicators
Indicators are chemicals (coloured dyes) which change colour in acids and alkalis.
Litmus
Turns red in acid
Turns blue in alkali
Litmus
Turns red in acid
Turns blue in alkali
Litmus can tell us if something is an acid or an alkali, but it cannot tell us
how strong the acid or alkali is
Other indicators
We are going to investigate today whether other substances can be used as indicators
Making an Indicator
Substance Colour (neutral)
Colour with acid
(HCl)
Colour with alkali (NaOH)
A good indicator?
Red cabbage
Beetroot
Coffee
Red cake decoration
Can you quickly, quietly and sensibly gather around
Mr Porter? (You’ll need your stools)
Test!
Don’t forget you have a test Friday on
Digestion (8A)!