How many joules of energy are needed to change 275 g of water from 15°C to steam at 100.°C?

Answer 1

q1 = heat needed to raise T from 15 C to 100 C.
q1 = mass H2O x specific heat H2O x (Tfinal-T(intial)

q2 = heat need to change liquid H2O to vapor.
q2 = mass H2O x heat vaporization
Total Q = q1 +q2