Express your answer to two significant figures and include the appropriate units.

Question

The density of liquid oxygen at its boiling point is 1.14 kg/L , and its heat of vaporization is 213 kJ/kg .

How much energy in joules would be absorbed by 4.0 L of liquid oxygen as it vaporized?

Answer 1

Use the conversion technique. Cancel units and go from one extensive variable to another (extensive variables are all proportional to the amount of stuff involved):

4.0 liters O₂ (1.14 kg/liter O₂)(213 kJ/kg of O₂)(1000 J/ kJ) = Joules

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