Suppose that the microwave radiation has a wavelength of 10.8 cm. How many photons are required to heat 225 mL of coffee from 25.0*C to 62.0*C ? Assume that the coffee has the same density, 0.997 g/mL , and specific heat capacity, 4.184 J/(gK), as water over this temperature range

Answer 1

Energy = hc/wavelength. Make sure you change wavelength to meters. E in joules and that is for one(1) photon.
q for water = mass x specific heat x delta T. Use density to determine mass coffee.
So haw many photons will be required to get that many joules?

Answer 2

2.30