OCR Module 5 Welcome to your OCR Module 5 Which of the following do not affect the value of Kp and Kc?I. TemperatureII. PressureIII. Concentration II and III only III only II only I and III only What is the effect of increasing Kp on the equilibrium of a reaction? Product yield increases Product yield decreases Kp does not affect the equilibrium Activation energy decreases Which of the following statements is incorrect? Kw is constant at all temperatures Increasing the temperature causes a decrease in the pH of water Kw is derived from Kc The unit of Kw is mol2/dm6 Assuming complete dissociation, what is the pH of 0.5M potassium hydroxide (KOH)? 13.7 13 10.6 14 What is an acidic buffer is made of? A solution of weak acid and its salt A solution of salt of a weak acid A weak acid A weak base Which of the following orders is correct such that the first compound has the most negative lattice enthalpy and the last one has the least negative? MgO, BaCl<sub>2</sub>, KCl KCl, BaCl<sub>2</sub>, MgO BaCl<sub>2</sub>, MgO, KCl KCl, MgO, BaCl<sub>2</sub> What causes a difference in theoretical and Born-Haber lattice enthalpies? Polarisation of negative ion 100% ionic character of compound Spherical shape of ions All of the options What can be said about entropy change when solid ammonium chloride decomposes to ammonia and hydrogen chloride gas? It's positive It's negative It remains the same It's unpredictable What material is used as an electrode of a standard hydrogen electrode (SHE)? Platinum Silver Copper Titanium Which of the following statements is true? More negative half cell oxidises More negetive half cell reduces Powerful oxidising agents have lower oxidation numbers The EMF of a cell is the same as the EMF of the reduction half-reaction Which of the following affect the EMF of a cell?I. ConcentrationII. Temperature I and II I only II only None of them Which of the following can cause colour changes in compounds of a transient element?I. LigandII. Coordination numberIII. Oxidation state I, II, and III I and II only III only I only Which of the following statements about the oxidation state of transient elements is not correct? Compounds with high oxidation states are often reducing agents Relative stability of +2 state with respect to +3 state increases across the period Compounds with a lower oxidation state tend to be reducing agents Vanadium has four main oxidation states Which of the following transition metals present in haemoglobin forms multidentate ligand with oxygen? Fe(II) Fe(III) Zn Cu(II) What type of reaction occurs between copper(II)hydroxide and excess ammonia? Ligand substitution Neutralisation Disproportionation Deprotonation A solution containing halide ions is acidified and the silver nitrate is added. A yellowish-white precipitate forms. To confirm which halid precipitate has formed, the student adds dilute ammonia and observes that the precipitate does not dissolve. Which halid ion could have been present in the original solution? Bromide or iodide Chloride or bromide Bromide Iodide The rate of a reaction is not affected by a change in concentration of a reactant X. What is the order of the reaction with respect to X? Zero First Second The order cannot be determined with the given information A reaction is first order with respect to reactant X and second order with respect to reactant Y. If the concentration of X is doubled and the concentration of Y is tripled, by what factor has the rate increased? 18 times 6 times 12 times 8 times A reaction rate increases 9 times by tripling the concentration of reactant A. What is the order of the reaction with respect to A? 2nd 1st Zero 3rd A mixture has a total pressure of 2kPa, contains 0.2 mol of nitrogen and 0.6 mol of oxygen. What is the partial pressure of the nitrogen gas in the mixture? 0.5 1.5 0.75 0.25
