Re: Does the temperature of jar affect how long it will take to burn out candle

I suspect that the candle burned out faster when encased in the hot jar because there was less air present. When air is hotter, it is less dense than when it is cold (density is defined as the amount of “stuff” in a given amount of volume). Incidentally, this is why hot air rises and cold air sinks. In the colder jar, there were more oxygen molecules present, and so the candle’s flame was able to burn longer. In addition, the higher temperature means that the air molecules in the hot jar had more energy than in the cold jar. In general, higher temperatures support faster rates of reaction rates, or the speed at which reactants (candle wax and oxygen) are turned into products (carbon dioxide and water, which are the main products in combustion reactions). Because you aren’t dealing with an airtight system, the pressure in each jar will be the same, so we can ignore pressure as a reason for the shorter burn time. So the high temperature coupled with less air led to a shorter burn time for the candle under the hot jar.

Below is a link with an excellent summary of what will affect rates of reaction: http://www.chem4kids.com/files/react_rates.html

Hope this helps.