Answer:
E = 1.8 x 10⁵ J/mol
Explanation:
We are being asked the enery per mol for an emission line corresponding to 649 nm.
The energy of a photon is given by the porduct of Planck's contant times the frequency of the radiation,
E = hν
We also know that the frequency is given by
ν = c/λ
where c is the speed of light (3 x 10 ^8 m/s) and λ is 649 nm given in the problem. Therefore the energy per photon will be given by
E= hc/λ = 6.626 x 10⁻³⁴Js x 3 x 10 ^8 m/s/ 649 x 10 ⁻⁹ m
E = 3.1 x 10 ⁻¹⁹ J/ photon
(Note the wavelength has to be in nanometers (1nm= 10⁻⁹ m) and that the energy we get is the energy per a single photon. Thus we will need to multiply this result by Avogadro's number to answer this question.
E = 3.1 x 10 ⁻¹⁹ J/ photon x 6.022 x 10 ²³photon/mol
E = 1.8 x 10⁵ J/mol
CH4 (g) + 2Cl2 (g) --> CH2Cl2 (g) + 2HCl (g) <span>ΔH = -205.4</span>
Heat lost (metal)=Heat gained (water)
Q in = Q out
So energy gained by the water = 1200 J
The answer is: supersaturated solution.
A supersaturated solution contains more of the dissolved substance than could be dissolved by the solvent under normal circumstances.
A way to dissolve more sugar into a solution is heating a solution.
The more heat is added to a system, the more soluble a substance (in this example sugar) becomes.
The solution will become supersaturated if this solution is suddenly cooled at a rate faster than the rate of precipitation.