TUTTEE ACADEMY LOGO
broken image
  • Home
  • About Us
  • Subjects 
    • CHEMISTRY
    • BIOLOGY
    • PHYSICS
    • MATHEMATICS
    • PSYCHOLOGY
    • ECONOMICS
    • BUSINESS
    • COMPUTER SCIENCE
    • CHINESE
    • ENGLISH
    • SPANISH
    • IBDP IA / EE
    • IBDP TOK
    • ONLINE TUTORIAL
  • Exam Boards 
    • IBDP
    • IBMYP
    • IGCSE & GCSE
    • HKDSE
    • GCE A-LEVELS
  • Courses 
    • IBDP Tuition
    • GCE A-Level Tuition
    • IBMYP Tuition
    • I/GCSE Tuition
    • HKDSE Tuition
  • Admission Test Prep 
    • PREDICTED GRADE
    • SAT / SSAT
    • UKISET (UK)
    • BMAT
    • UKCAT / UCAT
    • LNAT
    • TMUA (Cambridge)
  • Student Results 
    • IBDP STUDENT RESULTS
    • IGCSE & GCSE MATHEMATICS
    • A-LEVEL STUDENT RESULTS
    • IGCSE STUDENT RESULTS
    • GCSE STUDENT RESULTS (UK)
    • HKDSE STUDENT RESULTS
    • OUR STORIES
  • Question Bank
  • Resources
SCHEDULE A LESSON NOW

AS/A-Level Chemistry - Formation of coloured ions

Formation of coloured ions

· A-level Chemistry,coloured ions,Transition metal,oxidation state,electron orbitals

Transition metals have different colours in aqueous state, let's see how they are formed in A-Level Chemistry!

Transition metals can be identified by their colour. Their colour arises from partly filled d-orbitals, which allow electrons to move from one d-orbital to another. All transition metals by itself have d-orbitals of the same energy, but in the presence of lignands, d-orbitals splitting will occur, such that the d-orbitals start getting different energies.

broken image

When an electron moves from its ground state (its lowest energy level) to an excited state (to a higher d-orbital), it needs to absorb photons of a certain wavelength. The rest of the wavelengths belonging to the visible light spectrum combine to give the colour we see.

broken image
broken image

The equation linking frequency to the difference in energy levels of the d-orbitals is given:

broken image

where delta E is the difference in energy levels;

h is Planck's constant 6.63 x 10-34 Js;

f is the frequency of the wavelength;

c is the speed of light in vacuum 3 x 108 ms-1;

and lambda is the wavelength.

This means that the colour can be affected by:

  • the lignad itself
  • the coordination number, which affects the geometry of the complex
  • the oxidation state and therefore, charge on the transtion metal ion

The colorimeter

We can compare the concentration of transition metal ions relative to each other by comparing how deep their colours are, using a colorimeter:

  1. place sample in a small cylindrical container called a cuvette
  2. a filter is chosen
  3. a light shines through this filter and the %absorbance is measured through how much of the light makes it through the mixture and detected in the photocell
  4. a graph calibration graph is plotted
broken image
broken image

CLICK HERE TO LEARN MORE ABOUT OUR A-LEVEL CHEMISTRY COURSES

SIGN UP FOR OUR A-LEVEL CHEMISTRY TRIAL NOW

Drafted by Eunice (Chemistry)

References

https://qsstudy.com/chemistry/describe-formation-coloured-ions-d-block-elements

https://secondaryscience4all.wordpress.com/2014/08/10/formation-of-coloured-ions/

Subscribe
Previous
I/GCSE Biology - Genetics
Next
A2/A-level Biology - Genetic Fingerprinting
 Return to site
Profile picture
Cancel
Cookie Use
We use cookies to improve browsing experience, security, and data collection. By accepting, you agree to the use of cookies for advertising and analytics. You can change your cookie settings at any time. Learn More
Accept all
Settings
Decline All
Cookie Settings
Necessary Cookies
These cookies enable core functionality such as security, network management, and accessibility. These cookies can’t be switched off.
Analytics Cookies
These cookies help us better understand how visitors interact with our website and help us discover errors.
Preferences Cookies
These cookies allow the website to remember choices you've made to provide enhanced functionality and personalization.
Save