It is possible to use a small flame to boil water in a styrofoam cup without burning or melting the cup. The heat is absorbed by the water before the styrofoam gets hot enough to melt. If a flame is too hot, however, the cup will melt; this trick works better with a paper cup.
Specific heat, or heat capacity, describes the amount of energy which must be put into the substance to increase its temperature. Water has a relatively high specific heat--it takes one calorie, or 4.2 joules, to increase the temperature of one gram of water by one degree Celsius. The same amount of energy would heat up a piece of metal much faster. Because water has a high specific heat, it is able to quickly absorb the heat of the flame and keep the styrofoam cool.
Thermal conductivity is a measure of how quickly a heat difference transfers from one side of an object to the other. Styrofoam has a very low thermal conductivity, which is why it is used to insulate coolers and coffee cups. Paper has a higher thermal conductivity, which is why it is even easier to boil water in a paper cup without burning it.
Water boils at 100°C or 212°F at normal air pressure at sea level. The melting point of styrofoam varies depending on the exact type, but it is usually around 250°F or higher. As long as the flame is small enough that the heat has time to be transfer from the styrofoam to the water, the water will boil before the cup melts.
- Photo Credit Jupiterimages/Photos.com/Getty Images
Which Fabrics Are the Best Insulators?
Knowing how to dress for the weather will help make the outdoors much more enjoyable. In cold weather climates, it is always...
How to Treat a Boiling Water Burn
Burns from boiling water, also known as scalds, cause the same damage to the body as other kinds of burns and therefore...
How to Melt Plastic Cups
You might want to melt plastic cups for several reasons. You can reform the melted plastic into a piece of art. You...
What Are the Dangers of Accidentally Burning Styrofoam?
Burning Styrofoam, or polystyrene, is the least appropriate way to get rid of it for both people and the environment. Research has...
Thermal Properties of Paper
Paper is a common material most often used for writing, drawing or printing. Like all materials, paper has thermal properties. Thermal properties...
Insulation Properties of a Paper Cup
Restaurants and coffee shops use paper cups to serve coffee and other beverages. They are convenient to use and easy to dispose...