11. Group 17
A section of Chemistry, 9701
Listing 10 of 617 questions
Ethene, C2H4, and hydrazine, N2H4, are hydrides of elements which are adjacent in the Periodic Table. Data about ethene and hydrazine are given in the table below. C2H4 N2H4 melting point/°C –169 +2 boiling point/°C –104 +114 solubility in water insoluble high solubility in ethanol high high Ethene and hydrazine have a similar arrangement of atoms but differently shaped molecules. What is the H-C-H bond angle in ethene? Draw a ‘dot-and-cross’ diagram for hydrazine. What is the H-N-H bond angle in hydrazine? The melting and boiling points of hydrazine are much higher than those of ethene. Suggest reasons for these differences in terms of the intermolecular forces each compound possesses. Explain, with the aid of a diagram showing lone pairs of electrons and dipoles, why hydrazine is very soluble in ethanol. Ethene and hydrazine each react with HCl. When ethene is reacted with HCl, C2H5Cl is the only product. Using structural formulae, give an equation for the reaction between ethene and HCl. What type of reaction occurs between HCl and ethene? Explain why there is no further reaction between C2H5Cl and HCl. When aqueous hydrazine is reacted with HCl, a solid compound of formula N2H5Cl may be isolated. When an excess of HCl is used, a second solid, N2H6Cl2, is formed. Suggest what type of reaction occurs between hydrazine and HCl. What feature of the hydrazine molecule enables this reaction to occur? Suggest why one molecule of hydrazine is able to react with one or two molecules of HCl.
9701_s07_qp_2
THEORY
2007
Paper 2, Variant 0
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State and explain the relative rate of hydrolysis of acyl chlorides, alkyl chlorides and arylchlorides. > > fastest slowest The drug remifentanil is shown. O O remifentanil O O O N N Remifentanil is completely hydrolysed under acidic conditions. Three different organic compounds are formed. Draw the structures for these organic compounds in the boxes.  CompoundY, C5H10O2, reacts with Na2CO3to evolve bubbles of gas. The proton (1H) NMR spectrum of compoundY in D2O is shown. / ppm Use this information to suggest a structure for Y.  Use the Data Booklet, the proton (1H) NMR spectrum and your answer to to complete the table. chemical shift (δ) environment of proton splitting pattern number of 1H atoms responsible for the peak 0.95 1.90 2.20  
9701_s21_qp_42
THEORY
2021
Paper 4, Variant 2
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Radium, Ra, is an element found in Group2 of the Periodic Table. It is a crystalline solid at room temperature and conducts electricity. Radiumchloride, RaCl 2, has a melting point of 900 °C and is soluble in water. Predict the lattice structure of RaCl 2based on the properties described. Draw a dot-and-cross diagram to show the arrangement of outer electrons in RaCl 2.  Solid Ra and Ca show similar reactions with H2O, but the reactions occur at different rates. Separate samples, each containing a single piece of solid Ra or Ca, are added to equal volumes of cold water. Each sample contains equal numbers of moles of solid and the H2O is in excess. Construct an equation for the reaction of Ra with H2O. Identify which element, Ra or Ca, reacts with H2O at a faster rate. Suggest how the observations of each reaction would differ. Suggest why these reactions occur at different rates. One of the solutions is cloudy when the reaction has finished. At the end of each reaction, universal indicator is added to each reaction mixture. Suggest pH values of the solutions made in both reactions. Explain your answer. A sample of aqueous calcium halide, CaX2, contains either chloride, bromide or iodide ions. Complete Table2.1 to describe a two-step process that could be used to identify the halide ion present. Table 2.1 step method observation with CaCl 2 observation with CaBr2 observation with CaI2 step 1 step 2  
9701_s22_qp_22
THEORY
2022
Paper 2, Variant 2
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Use By choosing the chlorides of two of the Group IV elements as examples, describe the trend in the reactions of these chlorides with water. Suggest an explanation for any differences, and write equations for any reactions that occur. The standard enthalpy changes of formation of lead(chloride and lead(chloride are given in the following table. compound ∆H o f / kJ mol–1 PbCl2–359 PbCl4–329 Use these data, and also bond energy data from the Data Booklet, to calculate the enthalpy changes for the following two reactions. CCl2+ Cl2CCl4∆H o = kJ mol–1 PbCl2+ Cl2PbCl4∆H o = kJ mol–1 Make use of your answers to parts and to suggest how the relative stabilities of the two oxidation states vary down the Group.
9701_w07_qp_4
THEORY
2007
Paper 4, Variant 0
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Questions Discovered
617