effect of dissolved carbon dioxide on pH of water (1 Viewer)

[soboredrightnow]

Hey all,
so i have a prac assessment in 2days and i was wondering has anyone done this prac:
"perform a first-hand investigation to demonstrate the effect of dissolved carbon dioxide on the pH of water"
If you have, any info you can give me about it would be GREATLY appreciated!!
Its my first bio assesment of yr12 and i really want to do much better this year than i did in yr11!!

Thanx!!!

 

[shanti96]

Blow through a straw into the water... CO2 from breath will decrease PH (increase acidity) of the water...have a control and its all pretty simple.

 

[capslock]

calcium carbonate (marble chips/powder) will create CO2 gas when mixed with HCl. Using calcium carbonate powder and higher concentration HCl will increase the rate of reaction while using more dilute HCl or calcium carbonate chips will decrease the rate of reaction. I advise you to test possible combinations of these variables to create the combination that will favour the highest output of volume of CO2. You can test this by bubbling it through limewater and seeing how cloudy it goes. Then collect the CO2 gas and bubble it through your water and use either litmus paper or universal indicator to test the solution. Make sure u test your water with the indicator before you bubble through the C02.

Ask if you need more info

 

[Campione]

Okay I'm currently starting my Year 12 in 2008. I've done this experiment before. It's very easy to perform. First you must remember the purpose of this experiment, which is Carbon Dioxide dissolving in water (C02) in the form of Hydrogen Carbonate Ions (HC03-) to form an acid called Carbonic Acid (H2C03). We know that we as homosapiens we must excrete Carbon Dioxide by exhaling it from our lungs(alveoli) out through our noses. Carbonic Acid (H2C03) thus lowers our PH level from approximately 7 and makes it more acidic(lowering it), and also to conclude alters our haemoglobin's shape, which if you're studying Maintaining a Balance at this moment you should probably know what it is. If you don't know what haemoglobin is, it is made of Iron which assists in transporting oxygen molecules and red blood cells trhought out circulatory system consisting of the arteries, capillaries and veins. I might not have said this before, but in Biology there is a linkage with many aspects of the Human Body.


Now onto the experiment. If you're writing up this method try not to Plagarise. I am only trying to help you not to let you copy, if you want you can use this method but you must change the wording.

Equipment
Conical Flask, Cork, Delivery Tube, Beaker, Hydrochloric Acid(HCI), Calcium Carbonate(CaC03), water(tap water will do fine), universal indicator.

Method
1. First set up the experiment so that you have the conical flask first and the beaker beside it on the right.
2. Next place drill a hole in the center of the cork all the way through and then place the delivery tube through that hole.and then place the cork on top of the Conical Flask making sure that it fits and that there are no holes. (This task is the most essential mainly because if the Carbon Dioxide is evaporating from the Conical Flask and leaving it then the experiment will not work)
3. Before you do step two place some calcium carbonate into the Conical Flask, place a bit of Hydrochloric acid into the flask then place the cork along with the delivery tube on top.
4. Place some water in the beaker and then some universal indicator into the beaker.
5. Place the delivery tube into the beaker so that the carbon dioxide dissolves in the water.
6. Just observe the water and take a look at the change in PH.

The way I've described the experiment is not very complete. Just try it and you'll enjoy it. Good Luck

 

[radsss]

calcium carbonate (marble chips/powder) will create CO2 gas when mixed with HCl. Using calcium carbonate powder and higher concentration HCl will increase the rate of reaction while using more dilute HCl or calcium carbonate chips will decrease the rate of reaction. I advise you to test possible combinations of these variables to create the combination that will favour the highest output of volume of CO2. You can test this by bubbling it through limewater and seeing how cloudy it goes. Then collect the CO2 gas and bubble it through your water and use either litmus paper or universal indicator to test the solution. Make sure u test your water with the indicator before you bubble through the C02.

Ask if you need more info

thanks but how about if you need to test the presence of carbon dioxide? how would you do that?