C2O
CO
CO2
C2O2
Universal indicator - red
Limewater - cloudy
Litmus paper - blue
Lit splint - squeaky pop
H
H2
H
H2
Limewater - cloudy
Universal indicator - red
Lit splint - squeaky pop
Litmus paper - blue
Change of colour
Change of temperature
Change of odour
Change of state
Effervescence (bubbles)
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