Specific Heats of Water and Glycol

Problem Concepts of energy and temperature have not been adequately differentiated in students minds - heating with identical flame for identical periods of time leads, in their minds, to an identical temperature increase, if same portions of different substances have been chosen. But for exact same portions of two different liquids with clear differences in specific heat (4.18J/gK for water, 2.35 J/gK for glycol), identical amounts of energy leads to two completely different temperatures. If one takes a butane burner with a constant flame and constant period of time, the burner delivers the same amount of energy. This amount of energy is transferred to portions of water and glycol of the same masses, and the temperatures are compared. 

Material Two identical 250 ml beakers, butane burner, tripod and wire gauze, thermometer, balances, stopwatch water, ethylene glycol. 

Procedure Take two beakers and fill one with lOOg of water and the other with 100 g of ethylene glycol. Measure temperatures of both liquids. Place wire gauze on the tripod and heat with a burner adjusting a constant heat supply. Place the first beaker for 60 s on the heated wire gauze, then the second one. Measure the maximum temperature reached in each beaker. 

Observation The temperature of the water increases to about 15°C while glycol temperature increases to about 28°C. 

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