Question

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hul See Periodic Table See Hint Suppose an oven's radiation wavelength is 0.125 m. A container with 175.00 g of water was placed in the oven, and the temperature of the water rose from 20.0°C to 80.0°C. How many photons of this microwave radiation were required to heat the water? (Assume that all the energy from the radiation was used to raise the temperature of the water.) photons

Answer 1

1st calculate the heat required

Given:

m = 175 g

C = 4.184 J/g.oC

Ti = 20 oC

Tf = 80 oC

use:

Q = m*C*(Tf-Ti)

Q = 175.0*4.184*(80.0-20.0)

Q = 43932 J

Given:

lambda = 0.125 m

calculate energy of 1 photon

use:

E = h*c/lambda

=(6.626*10^-34 J.s)*(3.0*10^8 m/s)/(0.125 m)

= 1.59*10^-24 J

number of photon = total energy/energy of 1 photon

n = 43932.0/1.59*10^-24

= 2.763*10^28

Answer: 2.76*10^28