Does gaseous carbon dioxide turn moist blue litmus paper red?

Question

Does gaseous carbon dioxide turn moist blue litmus paper red?

Answer 1

Yeah you are correct.The reason being is because carbon dioxide is a acidic oxide.Thus it will turn litmus paper red

Answer 2

I've never tried this personally, but from a chemical standpoint, the answer is yes.  CO2 is an acidic oxide, indicating when dissolved in water, it will form an acid.  The equation for this is as follows:

CO2 + H2O ---> H2CO3

The product, H2CO3, is known as carbonic acid.  It is considered a weak acid, but one of the protons will leave the molecule readily enough to cause a pH change, or create an acidic medium.  Having said this, "moist" indicates the litmus paper contains H2O, therefore, if you have an appreciable amount of CO2 around, you will generate some carbonic acid.  Since acid turns litmus paper red, the paper will turn a shade of red.

Something to keep in mind is that rain water is generally acidic due to the amount of CO2 in the atmosphere.  Having said this, water on litmus paper is likely to be slightly acidic in nature and would therefore turn the paper red as well.

That was a drawn out answer to a question you may have wanted a simple yes or no to, but I hope you find this interesting.