Transition metals OCR A Level Chemistry Comprehensive Exam With Questions & Correct 100% Verified Answers

Which 2 transition metals do not have a fully filled 4s orbital? - correct answer Chromium and copper What advantage does a fully or half filled shell give a transition metal and why? - correct answer Makes more stable What is the definition of a transition element? - correct answer D-block element which form at least one ion with a partially filled d orbital Which 2 elements in the d block do not qualify as transition metals and why? - correct answer Zinc and scandium. Their ions have full d orbitals and not partially filled d orbitals What are the 3 properties of transition metals? - correct answer Have variable oxidation states, form coloured compounds and can act as catalysts Give an example of 2 different transition metals with variable oxidation states? - correct answer Fe 2+ to Fe3+ and Cr2+ to Cr3+ Why do transition metals form coloured compounds? - correct answer White light is absorbed by some wavelengths in the solution of the metal ion What are the advantages and disadvantages of using transition metals in industry as catalysts? - correct answer Advantages - reduces energy usage Disadvantages- many TM are toxic Describe an experiment to demonstrate how transition metals act as catalysts? (use equations) - correct answer 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+ When is a complex ion formed? - correct answer When one or more molecules bind to central metal atom What is a ligand? - correct answer A molecule or ion which donates a pair of electrons to a central metal ions to form a coordinate bond What is a dative covalent bond? - correct answer The bond formed between 2 atoms- one of which provides both electrons for the shared pair What is the coordination number? - correct answer Number of coordinate bonds Give an example of a monodentate ligand? - correct answer H2O Give 2 examples of a bidentate ligand? - correct answer Ethandioate ion or Nh2Ch2Ch2Nh2 (en) Give examples of two complex ions with a tetrahedral shape? - correct answer CuCl4 and CoCl4 Which elements will form complex ions with a square planar shape? - correct answer Ag (gold), Pt (platinum) and Pd (palladium) How are cis-trans isomers represented in square planar complexes? - correct answer Cis- same half, so they are 90 degrees apart (above and below each other on the same side) Trans- 180 degrees away, facing in opposite corners of the square In which kind of molecules does optical isomerism occur in in TM? - correct answe