What is the energy in joules of a mole of photons associated with visible light of wavelength 486 nm? (c = 3.00 × 108 m/s; h = 6.63 × 10–34 J • s; NA = 6.022 × 1023 moles–1)

The energy of a mole of photons is

Explanation:

The relation between energy and wavelength of light is given by Planck's equation, which is:

where,  

E = energy

h = Planck's constant  =

c = speed of light  = 3.0\times 10^8m/s

=  Avogadro's number =

= wavelength of photon = 486 nm =     (Conversion factor:   )

Putting values in above equation, we get:  

Hence, the energy of a mole of photons is

tracks, burrows, eggshells, nests, tooth marks, or gastroliths

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2