Acanister is filled with 310 g of ice and 100. g of liquid water, both at 0 ∘c . the canister is placed in an oven until all the h2o has boiled off and the canister is empty. how much energy in calories was absorbed?

Here in the process we require

1. Heat to melt down all ice

2. Heat to raise the temperature of whole water to 100 degree C

3. Heat to boil off the water

now here for the first part

Heat required to melt the ice

now heat required to raise the temperature to 100 degree C

Now heat required to boil it off

now the total heat required will be

so it required 287200 calorie heat to boil it all water

scattering of light by tiny particles in air to produce the colors we see on sky, is dependent on the following factors:

(i) wavelength of light

(ii) size of the scattering particle  

(iii) distance traveled by light through the atmosphere.

according to rayleigh's law of scattering, the amount of scattering is inversely proportional to the fourth power of its wavelength. shorter the wavelength, greater is its scattering. hence violet/blue light is scattered more than red.

sun's light is a composite light ( visible light) with wavelengths in the range 400 nm (violet) to 700 nm (red). as sunlight passes through our atmosphere, the molecules of air scatter light according to their wavelengths. during sunrise and sunset, the sun's position is below the horizon. hence light from the sun travels a greater distance in the atmosphere when compared to its position a noon.

as sunlight enters the earth's atmosphere, blue light is scattered away and at the end of its journey in the sky, only red and orange wavelengths remain in the beam.

hence at sunrise and sunset, the sky appears reddish orange.