acids, alkalis and titrations

what are the three indicators,

litmus

phenolphthalein

methyl orange

what does litmus change when its acidic, alkaline or neutral

acid- red

alkali- blue

neutral- purple

what does phenolphthalein show when it is acidic and alkali

acidic- colourless

alkali- bright pink

what does methyl orange show when it is acidic, neutral and alkali

acidic- red

alkali- yellow

neutral- orange

what is the ph scale 0-14 for strong acid, weak acid, neutral, weak alkali and strong alkali.

strong acid

• 0-3

weak acid

• 4-6

neutral

• 7

weak alkali

• 8-10

strong alkali

• 11-14

what does the univerwsal indicator do

universal indicator gives a certain colour to show the approximate ph level

what are the colours

red- strong acid

yellow- orange- weak acid

green- neutral

blue- weak alkaline

purple- strong alkaline

define acid

they are a substance that has a ph level lower than 7 and they contain hydrogen ions and are proton donors.

define bases-

substance that can neutralise and acid, they take the protons and they contain hydroxide ion.

define neutralisation

when the hydrogen ion from the acid reacts with the hydroxide ion from the base to form water

what is the word equation and the ionic equation of neutralisation

H+ + OH- —> H2O

acid + base —> salt + water

why are alkalis bases but not all bases are alkalis

since bases are a substance that neutralises and acid

and alkalis is a soluble base.

All alkalis are bases because they can dissolve in water, but not all bases are alkali because some bases cannot dissolve in the water. because

what is titration

it is an experiment that shows how much acid is needed to neutralise an alkali

what equipment must you know for titration

burette (measures variable volumes)

pipette (measures a fixed volume)

conical flask

indicator (methyl orange for example)

white tile (to see the colour change)

how would you do this investigation

get pipette and measure the volume of the alkali and put it into conical flask

add the indicator to the conical flask with the alkali

put the acid in the burette and record the initial volume

add acid into the conical flask slowly white swirling the flask

stop when the indicator changes colour

record the volume of the acid in the burette

calculate the volume of acid used