Question

1. The spectral line of a certain metal occurs at 665 nm (6.65×10^-7 m). Calculate the energy of one photon of this light

2. What is the wavelength, in nanometers, of light with a frequency of 1.67×10¹⁵ Hz?

3.

A mass of 7.75 g carbon monoxide is reacted with 8.04 g hydrogen to form methanol.

CO(g) + 2 H₂(g) → CH₃OH(g)

The reaction is performed in a 5.00 L flask at 85.0 °C and proceeds to completion. What is the partial pressure (in mmHg) of each of the three species following completion of the reaction? What is the total pressure in the flask?

CO =? mmHg

H₂ =? mmHg

CH₃OH =? mmHg

Total =? mmHg

Answer 1

1)

wavelength = 665 nm = 665 x 10^-9 m

energy E = h C / lamda

              = 6.625 x 10^-34 x 3 x 10^8 / 665 x 10^-9

energy E = 2.99 x 10^-19 J

2)

frequency = 1.67×10¹⁵

wavelength = c / v

                  = 3 x 10^8 / 1.67×10¹⁵

                  = 1.80 x 10^-7

                  = 179.6 nm