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A flask of water heated from 21 degrees Celsius to 85 degrees Celsius has absorbed heat, so its q is:
AImaginary
BPositive
CNegative
DExactly zero
Answer & Solution
Correct answer: B. Positive
1. The water ends hotter than it started, so heat has flowed into it.
2. The temperature of the water increases from 21 degrees Celsius to 85 degrees Celsius.
3. Because the temperature increased, the water absorbed heat and q is positive.
4. The size of that q depends on the mass, the specific heat and the 64 degree change.
5. A negative q would mean the water had cooled instead.
_Source: OpenStax Chemistry 2e (CC BY 4.0), Ch 5 'Thermochemistry', sections 5.1-5.3_
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