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How much heat is necessary to vaporize 500 g of water at its boiling point?

Answer 1

It depends on what temperature the water is starting at.

Two phase changes would occur if the water were solid. The equation for these changes is:

#q=mDeltaH_f#

The #DeltaH_f# should be given to you or easily accessible.

However, you need to know the starting temperature in order to calculate the amount of heat required to heat to a given temperature. The equation for that calculation is as follows:

#q=mC_sDeltaT#

Get that temperature information, and we can figure out what's missing from the question.

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Answer 2

Jose Ayala

The heat required to vaporize 500 g of water at its boiling point is approximately 2260 kJ.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.