A portable electric water heater transfers 255 watts (W) of power to 5.5 L of water, where 1 W = 1 J/s. How much time (in minutes) will it take for the water heater to heat the 5.5 L of water from 25 degrees celsius to 42 degrees celsius? (Assume that the water has a density of 1.0 g/mL)

Answer 1

How much heat is needed to raise the T of the water? That is
mass H2O(5500g) x specific heat H2O x (Tfinal-Tinitial) = q
255 J/s x #s = q
Solve for #seconds.