Temperature Video Lessons

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Problem: A standard mercury thermometer consists of a hollow glass cylinder, the stem, attached to a bulb filled with mercury. As the temperature of the thermometer changes, the mercury expands (or contracts) and the height of the mercury column in the stem changes. Marks are made on the stem to denote the height of the mercury column at different temperatures such as the freezing point (0°C ) and the boiling point (100°C ) of water. Other temperature markings are interpolated between these two points. Due to concerns about the toxic properties of mercury, many thermometers are made with other liquids. Consider draining the mercury from the above thermometer and replacing it with another, such as alcohol. Alcohol has a coefficient of volume expansion 5.6 times greater than that of mercury. The amount of alcohol is adjusted such that when placed in ice water, the thermometer accurately records 0 C. No other changes are made to the thermometer. A. When the alcohol thermometer is placed in 22 °C water, what temperature will the thermometer recordB. When the alcohol thermometer is placed in a -12 °C substance, what temperature will the thermometer record? C. If you want to design a thermometer with the same spacing between temperature markings as a mercury thermometer, how must the diameter of the inner hollow cylinder of the stem of the alcohol thermometer compare to that of the mercury thermometer? Assume that the bulb has a much larger volume than the stem.

FREE Expert Solution

A.

Alcohol expands more than mercury.

This is because it has a coefficient of volume expansion greater than that of mercury and hence will expand more than mercury.

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Problem Details

A standard mercury thermometer consists of a hollow glass cylinder, the stem, attached to a bulb filled with mercury. As the temperature of the thermometer changes, the mercury expands (or contracts) and the height of the mercury column in the stem changes. Marks are made on the stem to denote the height of the mercury column at different temperatures such as the freezing point (0°C ) and the boiling point (100°C ) of water. Other temperature markings are interpolated between these two points. Due to concerns about the toxic properties of mercury, many thermometers are made with other liquids. Consider draining the mercury from the above thermometer and replacing it with another, such as alcohol. Alcohol has a coefficient of volume expansion 5.6 times greater than that of mercury. The amount of alcohol is adjusted such that when placed in ice water, the thermometer accurately records 0 C. No other changes are made to the thermometer. 

A. When the alcohol thermometer is placed in 22 °C water, what temperature will the thermometer record

B. When the alcohol thermometer is placed in a -12 °C substance, what temperature will the thermometer record? 

C. If you want to design a thermometer with the same spacing between temperature markings as a mercury thermometer, how must the diameter of the inner hollow cylinder of the stem of the alcohol thermometer compare to that of the mercury thermometer? Assume that the bulb has a much larger volume than the stem.

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What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Temperature concept. You can view video lessons to learn Temperature. Or if you need more Temperature practice, you can also practice Temperature practice problems.