OCR A Level Chemistry: Transition metals. Exam Questions with Complete Answers. Verified for new Updates

1. Which 2 transition metals do not have a fully filled 4s orbital? - Ans .Chromium and copper 2. What advantage does a fully or half filled shell give a transition metal and why? - Ans .Makes more stable 3. What is the definition of a transition element? - Ans .D-block element which form at least one ion with a partially filled d orbital 4. Which 2 elements in the d block do not qualify as transition metals and why? - Ans .Zinc and scandium. Their ions have full d orbitals and not partially filled d orbitals 5. What are the 3 properties of transition metals? - Ans .Have variable oxidation states, form coloured compounds and can act as catalysts 6. Give an example of 2 different transition metals with variable oxidation states? - Ans .Fe 2+ to Fe3+ and Cr2+ to Cr3+ 7. Why do transition metals form coloured compounds? - Ans .White light is absorbed by some wavelengths in the solution of the metal ion 8. What are the advantages and disadvantages of using transition metals in industry as catalysts? - Ans .Advantages - reduces energy usage Disadvantages- many TM are toxic 9. Describe an experiment to demonstrate how transition metals act as catalysts? (use equations) - Ans .Reaction between iodide ions and peroxodisulfide ions catalysed by Fe2+. Normally blue black colour formed when trace of starch added. When Fe3+ is added, black colour forms much more quickly. Overall equation: S2O82- + 2I- -> 2SO4 2- + I2 With Fe2+: S2O82- + Fe2+ -> 2SO4 2- + Fe3+ Then: Fe3+ + 2I- -> I2 + Fe2+ 10. When is a complex ion formed? - Ans .When one or more molecules bind to central metal atom 11. What is a ligand? - Ans .A molecule or ion which donates a pair of electrons to a central metal ions to form a coordinate bond 12. What is a dative covalent bond? - Ans .The bond formed between 2 atoms- one of which provides both electrons for the shared pair 13. What is the coordination number? - Ans .Number of coordinate bonds 14. Give an example of a monodentate ligand? - Ans .H2O 15. Give 2 examples of a bidentate ligand? - Ans .Ethandioate ion or Nh2Ch2Ch2Nh2 (en) 16. Give examples of two complex ions with a tetrahedral shape? - Ans .CuCl4 and CoCl4 17. Which elements will form complex ions with a square planar shape? - Ans .Ag (gold), Pt (platinum) and Pd (palladium