11. Group 17
A section of Chemistry, 9701
Listing 10 of 617 questions
A transition element is a d-block element which forms one or more stable ions with incomplete d-orbitals. Two of the 3d orbitals are the 3dxy orbital and the 3dz2 orbital. Sketch the shapes of these two orbitals. 3dxy y z x 3dz2 z y x  The Ni2+ ion forms many different complexes. A solution containing the [Ni(H2O)6]2+ complex ion is green. When an excess of 1,2-diaminoethane, en, H2NCH2CH2NH2, is added, the colour of the solution changes to blue. This is due to the formation of the 2+ complex ion. Explain why the two solutions are coloured, and why the colours are different. The 2+ complex can exist as a mixture of two stereoisomers. Complete the three-dimensional diagram to show one of the stereoisomers. Each en ligand can be represented using N N . Ni  Name the geometry of the complex ion drawn in and the type of stereoisomerism shown by 2+. geometry stereoisomerism shown  Iron(carbonate, FeCO3, and nickel(carbonate, NiCO3, both decompose when heated. FeCO3 decomposes at a lower temperature than NiCO3. Suggest a possible reason for this difference. Explain your answer. A is a pale green salt containing Fe2+ ions. A sample of 2.62 g of A is dissolved in water and the solution is made up to exactly 100 cm3 with water. 25.0 cm3 samples of this solution are placed in conical flasks and titrated against 0.0100 mol dm–3 acidified potassiummanganate(. The equation for the only reaction that occurs is shown. 5Fe2+ + MnO4 – + 8H+ → 5Fe3+ + Mn2+ + 4H2O The average titre value is 35.0 cm3 of 0.0100 mol dm–3 acidified potassiummanganate(. Describe the colour change that is seen in the conical flask at the end-point of this titration. The colour changes from to �������������������������������������������� . Calculate the percentage by mass of iron in A. [Ar: Fe, 55.8]  percentage by mass of iron = % 
9701_w22_qp_41
THEORY
2022
Paper 4, Variant 1
View
A transition element is a d-block element which forms one or more stable ions with incomplete d-orbitals. Two of the 3d orbitals are the 3dxy orbital and the 3dz2 orbital. Sketch the shapes of these two orbitals. 3dxy y z x 3dz2 z y x  The Ni2+ ion forms many different complexes. A solution containing the [Ni(H2O)6]2+ complex ion is green. When an excess of 1,2-diaminoethane, en, H2NCH2CH2NH2, is added, the colour of the solution changes to blue. This is due to the formation of the 2+ complex ion. Explain why the two solutions are coloured, and why the colours are different. The 2+ complex can exist as a mixture of two stereoisomers. Complete the three-dimensional diagram to show one of the stereoisomers. Each en ligand can be represented using N N . Ni  Name the geometry of the complex ion drawn in and the type of stereoisomerism shown by 2+. geometry stereoisomerism shown  Iron(carbonate, FeCO3, and nickel(carbonate, NiCO3, both decompose when heated. FeCO3 decomposes at a lower temperature than NiCO3. Suggest a possible reason for this difference. Explain your answer. A is a pale green salt containing Fe2+ ions. A sample of 2.62 g of A is dissolved in water and the solution is made up to exactly 100 cm3 with water. 25.0 cm3 samples of this solution are placed in conical flasks and titrated against 0.0100 mol dm–3 acidified potassiummanganate(. The equation for the only reaction that occurs is shown. 5Fe2+ + MnO4 – + 8H+ → 5Fe3+ + Mn2+ + 4H2O The average titre value is 35.0 cm3 of 0.0100 mol dm–3 acidified potassiummanganate(. Describe the colour change that is seen in the conical flask at the end-point of this titration. The colour changes from to �������������������������������������������� . Calculate the percentage by mass of iron in A. [Ar: Fe, 55.8]  percentage by mass of iron = % 
9701_w22_qp_43
THEORY
2022
Paper 4, Variant 3
View
Questions Discovered
617