11. Group 17
A section of Chemistry, 9701
Listing 10 of 617 questions
Chlorine is a very reactive element. Chlorine reacts with silicon to form silicon(chloride. Describe the appearance of silicon(chloride at room temperature and pressure. State its structure and bonding. appearance structure and bonding Samples of magnesium chloride and phosphorus(chloride are added to separate beakers of cold water. Complete Table 3.1. Ignore temperature changes when considering observations for these reactions. Table 3.1 magnesium chloride phosphorus(chloride appearance at room temperature one similarity in observation on addition to cold water one difference in observation on addition to cold water pH of final solution State the reagent and conditions required for the formation of sodium chlorate(from Cl 2. Explain why the reaction in is described as a disproportionation reaction. Your answer should refer to relevant species and their oxidation numbers. Chlorine reacts with methane in a series of reactions to produce chloroalkanes. State the conditions required for chlorine to react with methane. One of the products of the reaction is CH2Cl 2 which reacts further to produce CHCl 3. Complete Table 3.2 to show details of the mechanism that forms CHCl 3 from CH2Cl 2. Table 3.2 name of step equation initiation propagation CH2Cl 2 + Cl • termination CHCl 3 CHCl 3 and HF are used to form CHCl F2 in a substitution reaction. Construct an equation for this reaction. X is a product of the substitution reaction that occurs when CHCl F2 reacts with Br2. There is only one naturally occurring isotope of fluorine, 19F. The mass spectrum of X shows molecular ion peaks at m / e = 164, 166 and 168. Complete Table 3.3 to show all the molecular ions responsible for each peak. Table 3.3 m / e formulae of molecular ions (CF2 37Cl 81Br)+
9701_s23_qp_21
THEORY
2023
Paper 2, Variant 1
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Nitrosyl chloride, NOCl, can be formed by the reaction between nitrogen monoxide and chlorine, as shown. 2NO + Cl 2 2NOCl The initial rate of this reaction is investigated, starting with different concentrations of NO and Cl 2. The results obtained are shown in Table 5.1. Table 5.1 experiment / mol dm–3 [Cl 2] / mol dm–3 initial rate / mol dm–3 min–1 0.0250 0.0150 3.68 × 10–2 0.0750 0.0150 3.32 × 10–1 0.0500 0.0600 5.89 × 10–1 Use the data in Table 5.1 to deduce the rate equation for this reaction. Explain your reasoning. Use your rate equation from and the data from experiment 1 to calculate the rate constant, k, for this reaction. Include the units of k. k = units NO2Cl is another compound containing nitrogen, oxygen and chlorine. In sunlight, NO2Cl can undergo homolytic fission to release chlorine radicals which can catalyse the conversion of ozone, O3, into oxygen. Complete the mechanism for this process. initiation (homolytic fission) NO2Cl + propagation step 1 + O3 + propagation step 2 + + Ozone reacts with nitrogen dioxide, as shown. O3 + 2NO2 N2O5 + O2 The rate of reaction is first order with respect to O3 and first order with respect to NO2. Suggest equations for a two‑step mechanism for this reaction. step 1 step 2 ,  ,
9701_s24_qp_42
THEORY
2024
Paper 4, Variant 2
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Chlorine gas is manufactured by the electrolysis of brine using a diaphragm cell. Write half-equations, including state symbols, for the reactions occurring at each of the electrodes of a diaphragm cell. anode cathode In the diaphragm cell, the anode is made of titanium and the cathode is made of steel. Suggest why steel is never used for the anode. One important product made in the diaphragm cell is formed in aqueous solution. What substance is produced in aqueous solution in the diaphragm cell? Explain, with the aid of appropriate half-equation, how this compound is formed by electrolysis. Chlorine is very reactive and will form compounds by direct combination with many elements. Describe what you would see when chlorine is passed over separate heated samples of sodium and phosphorus. In each case write an equation for the reaction. sodium phosphorus Magnesium chloride, MgCl2, and silicon tetrachloride, SiCl4, each dissolve in or react with water. Suggest the approximate pH of the solution formed in each case. MgCl2 ………………………………… SiCl4 ………………………………… Explain, with the aid of an equation, the difference between the two values.
9701_w08_qp_2
THEORY
2008
Paper 2, Variant 0
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Questions Discovered
617