Temperature Scales: Quiz

Temperature Scales: Quiz

7 questions

1. Question 1EasyWhat is 100 °C in °F?

   A180 °FB212 °FC132 °FD373 °F
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   Answer: 212 °F

   (9 °F/5 °C)(100 °C) + 32 °F = 180 °F + 32 °F = 212 °F, the boiling point of water at 1 atm.

2. Question 2EasyWhat is 50 °F in °C?

   A10.0 °CB27.8 °CC45.6 °CD−4.2 °C
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   Answer: 10.0 °C

   (5 °C/9 °F)(50 °F − 32 °F) = (5 °C/9 °F)(18 °F) = 10.0 °C. Multiplying by 5/9 before subtracting 32 gives the wrong value −4.2.

3. Question 3MediumAt what temperature do the Celsius and Fahrenheit scales show the same number?

   A0B−40C32D−273.15
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   Answer: −40

   Setting x = (9/5)x + 32 gives −(4/5)x = 32, so x = −40. Check: (9 °F/5 °C)(−40 °C) + 32 °F = −72 °F + 32 °F = −40 °F.

4. Question 4EasyWhat is 25 °C in kelvin?

   A−248.15 KB298.15 KC77 KD273.15 K
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   Answer: 298.15 K

   25 °C + 273.15 = 298.15 K.

5. Question 5MediumLiquid nitrogen boils at 77 K. What is this in °C?

   A350.15 °CB−196.15 °CC−77 °CD25 °C
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   Answer: −196.15 °C

   77 K − 273.15 = −196.15 °C (about −196 °C).

6. Question 6HardThe temperature of a solution rises by 20 °C. By how much does it rise in °F?

   A20 °FB36 °FC68 °FD52 °F
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   Answer: 36 °F

   For a change, use only the size factor: (1.8 °F/°C)(20 °C) = 36 °F. The 32 is not added, because it cancels when you subtract two temperatures.

7. Question 7MediumWhich statement about the kelvin scale is correct?

   AIt is written with a degree sign, °KBIts unit is larger than a Celsius degreeCIt starts at absolute zero, so it has no negative valuesDWater freezes at 0 K
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   Answer: It starts at absolute zero, so it has no negative values

   A kelvin is the same size as a Celsius degree, is written without a degree sign, and water freezes at 273.15 K.