Maintaining a Balance(9.2) Dot Point 2.7 - experiment...HOW DO I DO IT??? (1 Viewer)

[melimoo]

in maintaining a balance (9.2) Dot Point 2.7, it says

"perform a first-hand investigation to demonstrate the effect of dissolved carbon dioxide on the pH of water"

We have to design and perform the experiment by ourselves, so i was wondering if anyone who has already done it or knows what to do could tell me the method for this experiment, because i have absolutely no idea what it is talking about. thanks very much!!!!

 

[MaryTylerMoore]

Get a straw. Get a beaker of distilled water. Add a few drops of universal indicator and blow into the straw. The colour will change from green to yellow. CO2 + H2O -> H2CO3(aq) - carbonic acid. Which then forms HCO3- (aq) and H+ (aq) which is what makes it acidic. It can go again into H+ (aq) and CO3 2- (aq). CO2 makes water more acidic.

 

[lukebennett]

we did one with a straw and distilled water but no indicator. we used a pH meter and graphed th change in pH. it obviously decreases as H2CO3 forms which is an acid

 

[Misturi]

We used limewater instead.