A study of the Earth by The National Aeronautics and Space Administration (NASA) determined there were 7.80×1011 tons of carbon stored in living plants on the Earth's surface, at the time of the study. Calculate the mass of carbon stored in these plants in grams. (1 ton equals 907.19 kg)

Africtionless piston-cylinder contains 50 l of saturated liquid r-134a. the piston has a mass and an area resulting in an applied pressure of 500 kpa on the refrigerant. the refrigerant is now heated until its temperature rises to 70∘c. calculate the work (in kj) done during this process.