formation of coloured ions

Question 1

equation (Planck’s constant)

• used to work out “energy gap” , when electrons jump from ground state into excited state with the help of visible light.

Answer 1

change in E = hv

change in E = hc/lambda

v= freq of light absorbed (hz)

h= Planck’s constant (6.63x10^-34 J s)

c= The speed of light ( 3x10^8) m/s

lambda= wavelength of light absobed (m)

Question 2

Larger energy gap means…

Answer 2

Higher frequency of light absorbed

Question 3

How is the “complement colour” made?

Answer 3

The frequencies that are transmitted and reflected combine together to make the COMPLEMENT COLOUR of the absorbed frequencies

• this is the colour that we actually see.

Question 4

What happens to the colour when the 3d orbital is full?

Answer 4

no electrons will jump, so no energy is absorbed

• If there’s no energy absorbed, compound will look white.

Question 5

What 3 factors can affect size in energy gap?

Answer 5

1) changes in oxidation state
2) Changes in co-ordination number
3) changes in ligand.

Question 6

What is spectroscopy used for?

Answer 6

It can be used to find the concentration of a solution

by measuring how much light it absorbs

Question 7

How is a spectroscopy practical carried out?

Answer 7

1) White light is shone through a filter, so that only the colour of light that is absorbed by the sample can pass through
2) The light passes through the sample to a colorimeter, which calculates how much light was absorbed by the sample

Question 8

The more concentrated a coloured solution is….

Answer 8

The more light absorbed