Answer:
the equilibrium concentration of [PCl₅] is 3.64*10⁻³ M
Explanation:
for the reaction
PCl₅(g) → PCl₃(g) + Cl₂(g)
where
Kc= [PCl₃]*[Cl₂]/[PCl₅] = 2.0*10¹ M = 20 M
and [A] denote concentrations of A
if initially the mixture is pure PCl₅ , then it will dissociate according to the reaction and since always one mole of PCl₃(g) is generated with one mole of Cl₂(g) , the total number of moles of both at the end is the same → they have the same concentration → [PCl₃(g)] = [Cl₂]=0.27 M
therefore
Kc= [PCl₃]*[Cl₂]/[PCl₅] = 0.27 M* 0.27 M /[PCl₅] = 20 M
[PCl₅] = 0.27 M* 0.27 M / 20 M = 3.64*10⁻³ M
[PCl₅] = 3.64*10⁻³ M
the equilibrium concentration of [PCl₅] is 3.64*10⁻³ M
<u>Answer:</u> The mass of phosphorus that is present for given amount of calcium is 28.53 g.
<u>Explanation:</u>
We are given:
Mass of calcium = 50 grams
The chemical formula of calcium phosphate is 
Molar mass of calcium = 40 g/mol
Molar mass of phosphorus = 31 g/mol
In 1 mole of calcium phosphate, 120 grams of calcium is combining with 62 grams of phosphorus.
So, 50 grams of calcium will combine with =
of phosphorus.
Hence, the mass of phosphorus that is present for given amount of calcium is 28.53 g.
Answer:
343.98 nm is the longest wavelength of radiation with enough energy to break carbon–carbon bonds.
Explanation:
A typical carbon–carbon bond requires 348 kJ/mol=348000 J/mol
Energy required to breakl sigle C-C bond:E


where,
E = energy of photon
h = Planck's constant = 
c = speed of light = 
= wavelength of the radiation
Now put all the given values in the above formula, we get the energy of the photons.



343.98 nm is the longest wavelength of radiation with enough energy to break carbon–carbon bonds.