What is the energy of a photon of light having a wavelength of 4.5 x 10-7 meters? (planck’s constant is 6.626 x 10-34 joule seconds; the speed of light is 2.998 x 108 m/s)

4.4x10⁻¹⁹ J

Explanation:

The energy of a photon is given by the equation:

Where h is Planck's constant, c is the speed of light and λ is the wavelength.

Putting the data given by the problem we're left with.

So the answer is 4.4x10⁻¹⁹ J.

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.