9.2. Periodicity of chemical properties of the elements in Period 3
A subsection of Chemistry, 9701, through 9. The Periodic Table: chemical periodicity
Listing 10 of 224 questions
State the relationship between the Faraday constant, F, the charge on the electron, e, and the Avogadro number, L. If the charge on the electron, the Ar and the valency of copper are known, the value of the Avogadro number can be determined experimentally. This is done by passing a known current for a known time through a copper electrolysis cell, and weighing the mass of copper deposited onto the cathode. Draw a diagram of suitable apparatus for carrying out this experiment. Label the following: power supply (with + and – terminals); anode; cathode; and ammeter. State the composition of the electrolyte. The following are the results obtained from one such experiment. current passed through the cell = 0.500 A time current was passed through cell = 30.0 min initial mass of copper cathode = 52.243 g final mass of copper cathode = 52.542 g Use these data and relevant information from the Data Booklet to calculate a value of L to 3 significant figures. L = Use relevant information from the Data Booklet to identify the substances formed at the anode and at the cathode when aqueous solutions of the following compounds are electrolysed. compound product at anode product at cathode AgF FeSO4 MgBr2
9701_s11_qp_42
THEORY
2011
Paper 4, Variant 2
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State the relationship between the Faraday constant, F, the charge on the electron, e, and the Avogadro number, L. If the charge on the electron, the Ar and the valency of copper are known, the value of the Avogadro number can be determined experimentally. This is done by passing a known current for a known time through a copper electrolysis cell, and weighing the mass of copper deposited onto the cathode. Draw a diagram of suitable apparatus for carrying out this experiment. Label the following: power supply (with + and – terminals); anode; cathode; and ammeter. State the composition of the electrolyte. The following are the results obtained from one such experiment. current passed through the cell = 0.500 A time current was passed through cell = 30.0 min initial mass of copper cathode = 52.243 g final mass of copper cathode = 52.542 g Use these data and relevant information from the Data Booklet to calculate a value of L to 3 significant figures. L = Use relevant information from the Data Booklet to identify the substances formed at the anode and at the cathode when aqueous solutions of the following compounds are electrolysed. compound product at anode product at cathode AgF FeSO4 MgBr2
9701_s11_qp_43
THEORY
2011
Paper 4, Variant 3
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The ions of transition elements form complexes by reacting with ligands. State what is meant by the terms: complex, ligand. Two of the complexes formed by copper are [Cu(H2O)6]2+ and CuCl 4 2–. Draw three-dimensional diagrams of their structures in the boxes and name their shapes. [Cu(H2O)6]2+ shape: CuCl 4 2– shape: Platinum forms square-planar complexes, in which all four ligands lie in the same plane as the Pt atom. There are two isomeric complexes with the formula Pt(NH3)2Cl 2. Suggest the structures of the two isomers, and, by comparison with a similar type of isomerism in organic chemistry, suggest the type of isomerism shown here. Structures of isomers: isomer 1 isomer 2 Type of isomerism: Copper forms two series of compounds, one containing copper(ions and the other containing copper(ions. Complete the electronic structures of these ions. Cu( Cu( Use these electronic structures to explain why copper(salts are usually coloured, copper(salts are usually white or colourless. Copper(oxide and copper(oxide can both be used in the ceramic industry to give blue, green or red tints to glasses, glazes and enamels. The table lists the values for some compounds. compound / kJ mol–1 Cu2O–168.6 CuO–157.3 Cu(NO3)2–302.9 NO2+33.2 Copper(oxide can be produced in a pure form by heating copper(nitrate. Use suitable values from the table to calculate the H o for this reaction. Cu(NO3)2 CuO+ 2NO2+ 2 1 O2H o = kJ mol–1 Copper(oxide can be produced from copper(oxide. ● Use suitable values from the table to calculate H o for the reaction. 2CuOCu2O+ 2 1 O2H o = kJ mol–1 ● Hence suggest whether a low or a high temperature of oxidation would favour the production of copper(oxide. Explain your reasoning.
9701_s14_qp_41
THEORY
2014
Paper 4, Variant 1
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The ions of transition elements form complexes by reacting with ligands. State what is meant by the terms: complex, ligand. Two of the complexes formed by copper are [Cu(H2O)6]2+ and CuCl 4 2–. Draw three-dimensional diagrams of their structures in the boxes and name their shapes. [Cu(H2O)6]2+ shape: CuCl 4 2– shape: Platinum forms square-planar complexes, in which all four ligands lie in the same plane as the Pt atom. There are two isomeric complexes with the formula Pt(NH3)2Cl 2. Suggest the structures of the two isomers, and, by comparison with a similar type of isomerism in organic chemistry, suggest the type of isomerism shown here. Structures of isomers: isomer 1 isomer 2 Type of isomerism: Copper forms two series of compounds, one containing copper(ions and the other containing copper(ions. Complete the electronic structures of these ions. Cu( Cu( Use these electronic structures to explain why copper(salts are usually coloured, copper(salts are usually white or colourless. Copper(oxide and copper(oxide can both be used in the ceramic industry to give blue, green or red tints to glasses, glazes and enamels. The table lists the values for some compounds. compound / kJ mol–1 Cu2O–168.6 CuO–157.3 Cu(NO3)2–302.9 NO2+33.2 Copper(oxide can be produced in a pure form by heating copper(nitrate. Use suitable values from the table to calculate the H o for this reaction. Cu(NO3)2 CuO+ 2NO2+ 2 1 O2H o = kJ mol–1 Copper(oxide can be produced from copper(oxide. ● Use suitable values from the table to calculate H o for the reaction. 2CuOCu2O+ 2 1 O2H o = kJ mol–1 ● Hence suggest whether a low or a high temperature of oxidation would favour the production of copper(oxide. Explain your reasoning.
9701_s14_qp_43
THEORY
2014
Paper 4, Variant 3
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L and M are elements in Period 3 of the Periodic Table. Neither element is argon. Information about the Pauling electronegativity values of L and M is given. Pauling electronegativity value element the highest of the seven elements Na to Cl the lowest of the seven elements Na to Cl L M Three statements about elements L and M are given. Element L contains covalent bonds. Element L has a higher atomic number than element M. A compound of L and M contains ionic bonds. Which statements are correct?
9701_s23_qp_13
MCQ
2023
Paper 1, Variant 3
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