Calculate number of photons at given wavelength!!!!?

uiadpi11 - 2008-03-26 17:29:22 - Chemistry

A 381 g sample of water absorbs infrared radiation at 1.06 104 nm from a carbon dioxide laser. Suppose all the absorbed radiation is converted to heat. Calculate the number of photons at this wavelength required to raise the temperature of the water by 5.00°C.

Best Answer:

This is just unit conversion. Find the amount of heat (J) from Amount of heat = mass x specific heat x change in temperature Find the amount of energy (J/photon) from wavelength x frequency = speed (true for all travelling waves) = c (for light) and energy (J/photon) = frequency x Planck's Constant Then divide one number by the other. Take care that your units are consistent. Just bookkeeping, made to look difficult by joining together two different kinds of problem. Nothing more to it. Good luck.

Answer:

This is just unit conversion. Find the amount of heat (J) from Amount of heat = mass x specific heat x change in temperature Find the amount of energy (J/photon) from wavelength x frequency = speed (true for all travelling waves) = c (for light) and energy (J/photon) = frequency x Planck's Constant Then divide one number by the other. Take care that your units are consistent. Just bookkeeping, made to look difficult by joining together two different kinds of problem. Nothing more to it. Good luck.