1.30 In this question, all gases can be assumed to behave ideally. A chemist heats a mixture of nitrogen and oxygen gases in a sealed container at a constant temperature until the mixture reaches a dynamic equilibrium containing N2(g), O2(g) and NO(g). N2(g) + O2(g) 2NO(g) The chemist repeats the experiment at the same temperature using the same initial amounts of N2(g) and O2(g), but at a much higher pressure. Which statements about the second experiment at higher pressure are correct?   1 At higher pressure, there are more particles per unit volume. 2 The composition of the equilibrium mixture does not change. 3 There are more collisions per second, so equilibrium is reached faster.  

1.19 When solid ammonium chloride dissociates at a certain temperature in a 0.500 dm3 container, ammonia and hydrogen chloride are formed.   NH4Cl (s)< == > NH3(g) + HCl (g)   The initial amount of ammonium chloride was 1.00 mol, and when the system had reached equilibrium there was 0.300 mol of ammonium chloride.   What is the numerical value of Kc for this reaction under these conditions?  

1.25 In which reaction is the organic compound oxidised? A CH3CH2CH2CHO + Tollens’ reagent B CH3CH2CH2CHO + LiAlH4 C CH3CH2CH2OH + concentrated H3PO4 D CH3CO2C2H5 + dilute H2SO4

1.27 How many isomeric esters, including structural isomers and stereoisomers, can be made with the molecular formula C5H10O2, if methanoic acid is one of the two reactants used?

1.10 The equation for the reaction between carbon monoxide and hydrogen is shown. CO(g) + 3H2(g) CH4(g) + H2O(g) What are the units of Kp for this reaction?     Right-click on the button to open the data booklet in a new tab.     

1.14 The solids sodium chloride and sodium iodide both react with concentrated sulfuric acid at room temperature.   With NaCl, the products are NaHSO4 and HCl. With NaI, the products are NaHSO4, HI, I2, SO2, H2O, S and H2S.   What is the best explanation for this difference in products?

QUESTION 5   Compounds containing different halogen atoms covalently bonded together are called interhalogen compounds.   5.1 One interhalogen compound can be prepared by the reaction between iodine and fluorine. This compound has Mr = 222 and the percentage composition by mass is: F, 42.8; I, 57.2. Calculate the molecular formula of this interhalogen compound. [3] 5.2 Another interhalogen compound has the formula ICl. Draw a ‘dot-and-cross’ diagram of a molecule of this compound, showing outer shell electrons only. Explain whether or not you would expect this molecule to be polar. [2]     [5]  

QUESTION 4 Using the given skeletal formula, answer the questions.   Right-click on the button to open the data booklet in a new tab.      4.1 Give the skeletal formula of a structural isomer. [1] 4.2 Give the skeletal formula of a functional isomer [1]   From the following structures:   Right-click on the button to open the data booklet in a new tab.   Right-click on the button to open the data booklet in a new tab.        4.3 Identify the type of isomer. [1]     [3]

1.5 Carbon and silicon have the same outer electronic structure. Why is a Si–Si bond weaker than a C–C bond?

1.20 Which stage in the free radical substitution of ethane by chlorine has the lowest activation energy?     Right-click on the button to open the data booklet in a new tab.