Fun stuff
Read our general notes on Risk Assessment
Why does coca cola fizz when dropped? How can I find the pH of cola?
Jenkin writes ...
The best way to find the pH of cola is to test it with Universal Indicator paper! I would guess that it's well on the acid side of 7. A well-known experiment is to put a tooth into a cola drink: the tooth eventually dissolves, demonstrating the acidity of the drink. But don't offer to extract a classmate's tooth in the interest of science!
As to why it fizzes, cola, like other fizzy drinks is a solution of carbon dioxide in water. The gas is dissolved under pressure because gases are more soluble if the pressure is increased. Typically, the pressure used is about 2 atmospheres. When the pressure is released, normally by opening the bottle, the gas is less soluble so it it comes out of solution and the drink fizzes. This can also happen if the temperature is increased because gases are less soluble at higher temperatures. Dropping or shaking the bottle also makes the drink fizz but I can't think of an obvious reason.
Risk assessment
Before attempting any practical work based on the advice and suggestions on this website, you must do the following. Identify any hazards, assess the risks from these hazards, and then decide appropriate control measures to reduce the risks. You must have these approved by those in authority in your school or college laboratory. Do not rely on what is said on this website.
For further guidance see our tutorial on Risk Assessment.
Rate this page or react
Share your views on this page, 278 ratings so far
, rated at 
Reactions
This reminds me of an experiment a group of american scientists conducted a while ago. They placed a pretty beefy steak in a container of coke and returned a couple of days later to find it completely dissolved. And we drink that stuff!
Andrew Cockcroft 10 November 2003
I was shown a thing where if you place a dirty penny or 2p into a small amount of cola and leave it, it comes out shiny. Once again showing the lovely effect it must have on our teeth!
David 05 January 2004
updated: 02 July 2003
