Given that:
Volume of coffee = 8 fl.oz = 236.588 mL
because, 1 fl.oz = 29.5735 mL
Therefore, Mass of coffee = volume x density = (236.588 mL) x (1 g/mL) = 236.588 g
Specific heat capacity of coffee = heat capacity of water = 4.184 J/goC
Energy required to heat the coffee is given by:
H = mcΔT
H = (236.588 g) x (4.184 J/goC) x (60-23)oC
H = 36625.7 J
Energy per photon of the microwave radiation:
E = hc/λ
Where, c = speed of light = 3 x 108 m/s
E = (6.626 x 10-34 J.s x 3 x 108 m/s) / (0.112 m)
E = 1.7748 x 10-24 J/photon
Hence No.of photons required to heat the coffee:
N = Total energy required / energy per photon
N = (36625.7 J) / (1.7748 x 10-24 J per photon)
N = 2.064 x 1028 photons ---------- (answer).
Assumptions we made to solve this problem:
Chemistry 121 Name Ch. 7 Challenge Problem (out of 30 points) Microwave ovens use microwave radiation...
Microwave ovens use microwave radiation to heat food. The microwaves are absorbed by moisture in the food, which is transferred to other components of the food. As the water becomes hotter, so does the food. Suppose that the microwave radiation has a wavelength of 11.2 cm. How many photons are required to heat 200 mL of coffee from 25 C to 63 C?
Using Microwave Radiation to Heat Coffee (expanded) Microwave ovens use microwave radiation to heat food. The microwaves are absorbed by the water molecules in the food, which is transferred to other components of the food. As the water becomes hotter, so does the food. Part A Suppose that the microwave radiation has a wavelength of 12.4 cm . How many photons are required to heat 215 mL of coffee from 25.0 ∘C to 64.6 ∘C? The coffee has a density...
Microwave ovens use microwave radiation to heat food. The microwaves are absorbed by the water molecules in the food, which is transferred to other components of the food. As the water becomes hotter, so does the food. Suppose that the microwave radiation has a wavelength of 12.4 cm . How many photons are required to heat 235 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,...
Microwave ovens use microwave radiation to heat food. The microwaves are absorbed by the water molecules in the food, which is transferred to other components of the food. As the water becomes hotter, so does the food. Part A Suppose that the microwave radiation has a wavelength of 12.4 cm. How many photons are required to heat 285 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...
5. Microwave ovens emit microwave radiation that is absorbed by water. The absorbed radiation is converted to heat, which cooks the food. One particular oven emits microwaves with a wavelength of 10.8 cm. How many microwave photons are required to heat 150.0 mL of coffee from 20.0°C to 70.0°C? (q = mcpAT; Cwater = 4.18 J/gºC)
Microwave ovens heat food by creating microwave electromagnetic radiation that is absorbed by water molecules in the food. Any material that does not have water in it will not absorb the radiation and will not get hot. Metals reflect the microwaves from their surfaces and disrupt the operation of the oven. Some Australians heat water in microwave ovens to make tea. What is the minimum number of microwave photons with a wavelength of 3.17 mm that will have to be...
i need help with this problems Problem 7 Two microwave frequencies are authorized for use in microwave ovens: 900 MHz and 2,560 MHz. a) On its highest power setting, a microwave oven can produce 1.00 kW of power onto a 30.0 by 40.0 cm area. What is the intensity in W/m2? b) Calculate the peak electric and magnetic field strength in these waves. c) The maximum safe intensity of microwaves for human exposure is 1.00 W/m. If a radar unit...