neutralisation

what is measured into a conical flask?

25cm³ sodium hydroxide

what is conical flask placed on? (& why)

white tile (to see colour change)

what is burette filled with?

sulfuric acid

how much of which indicator is put into conical flask?

5 drops of phenolphthalein

what is the colour change as a result of neutralisation

pink —> colourless

why does this colour change happen?

because the sodium hydroxide is an alkali (hence phenolphthalein turns pink in it) and it is being neutralised by the sulfuric acid which is an acid.

what is a titre?

volume of acid used to neutralise the akali

how many times should investigation be repeated?

until consistant results (within 0.1cm³ of eachother)

what is done wth results? (excl. anomalies)

• present in table & calculate mean titre

• calc no. of moles of sodium hydroxide used

• calc. concentration off sulphuric acid used (conc = mol/vol)

Hazards

acids - wear safety goggles