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Grade 12 Chemistry national exam, 2006 E.C. (2014 G.C.)

73 questions · 120 minutes. The first 5 answers are shown with explanations; sit the whole paper timed in the app to get your score and the textbook page behind every question.

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  1. 1.Which of the following is NOT a conjugate acid-base pair?
    • A. $\mathrm{HNO_3/NO_3^-}$
    • B. $\mathrm{H_2SO_4/HSO_4^-}$
    • C. $\mathrm{NH_3/NH_2^-}$
    • D. $\mathrm{H_3O^+/OH^-}$
    Answer: D. Conjugate acid-base pairs differ by one proton, which is a hydrogen ion. $\mathrm{H_3O^+}$ and $\mathrm{OH^-}$ differ by two protons, so they are not a conjugate pair. $\mathrm{HNO_3/NO_3^-}$, $\mathrm{H_2SO_4/HSO_4^-}$, and $\mathrm{NH_3/NH_2^-}$ each differ by one proton. Textbook: Grade 12, unit 1 · section 1.1.2.
  2. 2.Which of the following is correct?
    • A. $1\mathrm{L}=1\mathrm{dm}^3$
    • B. $1\mathrm{L}=10\mathrm{dm}^3$
    • C. $10\mathrm{L}=1\mathrm{dm}^3$
    • D. $1\mathrm{L}=1\mathrm{m}^3$
    Answer: A. The question tests the link between units of volume. One litre equals one cubic decimetre: $1\,\mathrm{L}=1\,\mathrm{dm^3}$. B is ten times too large; C reverses the conversion; D gives a cubic metre, which is much larger. Textbook: Grade 9, unit 2 · section 2.1.
  3. 3.Commercially, liquid vegetable oils are converted to solid fats such as margarine by:
    • A. Hydrogenation
    • B. Hydration
    • C. Saponification
    • D. Oxidation
    Answer: A. This question tests how liquid oils are changed into solid fats. Hydrogen is added to the oil's carbon-carbon double bonds in hydrogenation, making the fat more solid, so A is correct. Hydration adds water; saponification makes soap from fats or oils; oxidation is not the process used to make margarine. Textbook: Grade 11, unit 6 · section 6.6.4.
  4. 4.What is the chemical name for Aspirin?
    • A. Acetyl salicylic acid
    • B. Salicylic acid
    • C. Methyl salicylate
    • D. Sodium salicylate
    Answer: A. The key idea is to know the chemical name of the medicine aspirin. Aspirin is acetyl salicylic acid. B names salicylic acid, which is not aspirin. C is methyl salicylate, a different compound. D is sodium salicylate, also a different compound. Textbook: Grade 11, unit 6 · section 6.6.1.
  5. 5.Which of the following statement(s) is (are) true of an ideal liquid-liquid solution? I. It obeys PV = nRT II. It obeys Raoult's law III. Solute-solute, solvent-solvent, and solute-solvent interactions are very similar. IV. Solute-solute, solvent-solvent, and solute-solvent interactions are quite different.
    • A. I, II and III
    • B. I, II and IV
    • C. II and III
    • D. II and IV
    Answer: C. An ideal liquid-liquid solution obeys Raoult's law when the different particle attractions are similar. Thus statements II and III are true. I is wrong because $PV=nRT$ describes an ideal gas. IV is wrong because ideal solutions have similar, not quite different, particle attractions. Textbook: Grade 10, unit 2 · section 2.2.
  6. 6.In a reaction, A + B product, the rate is doubled when the concentration of B is doubled, and the rate increases by a factor of 8 when the concentrations of both the reactants (A and B) are doubled, the rate law for the reaction can be written as: 2
    • A. Rate = K[A][B]
    • B. Rate = K[A][B] 2 2 2
    • C. Rate = K[A] [B]
    • D. Rate = K[A] [B]
    Answer, explanation and textbook page: open in the app.
Answer the following question using the phase diagram below. At which point can only the solid and liquid phases coexist? [Figure: A hand-drawn pressure-temperature phase diagram. The vertical axis is labelled 'Pressure' and the horizontal axis is labelled 'Temperature'. Three curves meet at a single point marked with a small open circle and labelled 3, sitting low and left of centre. From point 3 a straight steep line runs up and to the left, leaving the top of the drawing (the solid-liquid boundary); a filled square marked 4 sits on this line part-way up, and a filled dot sits higher on the same line. From point 3 an almost horizontal, slightly curving line runs left towards the pressure axis (the solid-gas boundary). From point 3 a curve rises gently to the right and then steepens, ending at a small circle labelled 8 at the upper right (the liquid-gas boundary); a small circle labelled 5 sits on this curve near its upper end. A dot labelled 1 lies in the region to the left of the steep line and above the almost-horizontal line. A dot labelled 2 lies in the open area above the rising right-hand curve and to the right of the steep line.
  1. 7.A dot labelled 6 lies below the rising right-hand curve, beneath point 5.]
    • A. 1
    • B. 2
    • C. 3
    • D. 4
    Answer, explanation and textbook page: open in the app.
  2. 8.Which electron transition in a hydrogen atom releases the largest energy?
    • A. n = 2 ?n = 1
    • B. n = 4 n = 2 → →
    • C. n = 6 n = 3
    • D. n = 7 n = 6 → →
    Answer, explanation and textbook page: open in the app.
  3. 9.The simplest formula for a compound containing $\mathrm{Mn^{4+}}$ and $\mathrm{O^{2-}}$ is
    • A. $\mathrm{MnO}$
    • B. $\mathrm{MnO_2}$
    • C. $\mathrm{Mn_2O_4}$
    • D. $\mathrm{Mn_4O_2}$
    Answer, explanation and textbook page: open in the app.
  4. 10.What is the ratio of the energy of a photon of 300 nm wavelength radiation to that of 600 nm radiation?
    • A. 1:2
    • B. 1:1
    • C. 2:1
    • D. 3:1
    Answer, explanation and textbook page: open in the app.
  5. 11.Which one of the following chemicals is used to disinfect water?
    • A. Fluorine
    • B. Nitrogen
    • C. Oxygen
    • D. Chlorine
    Answer, explanation and textbook page: open in the app.
  6. 12.During the titration of a known volume of a strong acid with a strong base, there is
    • A. A steady increase in PH
    • B. A sharp increase in PH around the end point
    • C. A steady decrease in PH
    • D. A sharp decrease in PH around the end point
    Answer, explanation and textbook page: open in the app.
  7. 13.A solution with a PH of 7.5 would be described as:
    • A. Very basic
    • B. Slightly base
    • C. Slightly acidic
    • D. Very acidic
    Answer, explanation and textbook page: open in the app.
  8. 14.The electrolysis of molten $\mathrm{NaCl}$ is an industrial process. What does the electrolysis produce?
    • A. $\mathrm{Na}$ and $\mathrm{Cl_2}$
    • B. $\mathrm{H_2}$ and $\mathrm{O_2}$
    • C. $\mathrm{Na^+}$ and $\mathrm{Cl^-}$
    • D. $\mathrm{NaOH}$ and $\mathrm{Cl_2}$
    Answer, explanation and textbook page: open in the app.
  9. 15.Butane burns in oxygen according to the equation below. . If 11.6g of butane is burned in 11.6 g of oxygen, which is the limiting reagent?
    • A. Butane
    • B. Oxygen
    • C. Neither
    • D. Both oxygen and butane
    Answer, explanation and textbook page: open in the app.
  10. 16.A beaker filled to the 100mL mark with salt (the salt has a mass of 100g) and another beaker to the 100mL mark with water (the water has a mass of 100g) are mixed together in a bigger beaker until the salt is completely dissolved. What will be the mass of the solution?
    • A. It will be much more than 200g
    • B. It will be much smaller than 200g
    • C. It will be exactly 200g
    • D. It will be slightly more than 200g
    Answer, explanation and textbook page: open in the app.
  11. 17.Which one of the following is NOT an intensive property?
    • A. Mass
    • B. Temperature
    • C. Colour
    • D. Density
    Answer, explanation and textbook page: open in the app.
  12. 18.Which of the following is natural polymer?
    • A. Nylon
    • B. PVC
    • C. Cotton
    • D. Dacron
    Answer, explanation and textbook page: open in the app.
  13. 19.Which of the following metals forms a volatile compound during the extraction process?
    • A. Fe
    • B. Co
    • C. Ni
    • D. Cu
    Answer, explanation and textbook page: open in the app.
  14. 20.Which one of the following atoms in its ground state has the greatest number of unpaired electrons?
    • A. ${}_{13}\mathrm{Al}$
    • B. ${}_{14}\mathrm{Si}$
    • C. ${}_{15}\mathrm{P}$
    • D. ${}_{16}\mathrm{S}$
    Answer, explanation and textbook page: open in the app.
  15. 21.Which statement is true about chemical reactions at equilibrium?
    • A. A forward and backward reactions proceed at equal rates
    • B. The forward and backward reactions have stopped
    • C. The concentrations of the reactants and products are equal
    • D. The forward reaction is exothermic
    Answer, explanation and textbook page: open in the app.
  16. 22.Which compound contains both covalent and ionic bonds?
    • A. Sodium carbonate, $\mathrm{Na_2CO_3}$
    • B. Magnesium bromide, $\mathrm{MgBr_2}$
    • C. Dichloromethane, $\mathrm{CH_2Cl_2}$
    • D. Ethanoic acid, $\mathrm{CH_3COOH}$
    Answer, explanation and textbook page: open in the app.
  17. 23.Which set of quantum numbers (n, l, , ) is not possible?
    • A. 1, 0, 0, 1/2
    • B. 1, 1, 0, 1/2
    • C. 1, 0, 0, -1/2
    • D. 2, 1, -1, 1/2
    Answer, explanation and textbook page: open in the app.
  18. 24.Which of the following particles contains more electrons than neutrons? I. II. III.
    • A. I only
    • B. II only
    • C. I and II only
    • D. II and III only
    Answer, explanation and textbook page: open in the app.
  19. 25.Which molecule or ion does NOT have a tetrahedral shape?
    • A. $\mathrm{XeF_4}$
    • B. $\mathrm{SiCl_4}$
    • C. $\mathrm{BF_4^-}$
    • D. $\mathrm{NH_4^+}$
    Answer, explanation and textbook page: open in the app.
  20. 26.Why are metals soft and malleable?
    • A. Because they are very shiny.
    • B. Because they experience electrostatic repulsion
    • C. Because of the presence of mobile electrons.
    • D. Because the metal cations can slip over each other fairly easily.
    Answer, explanation and textbook page: open in the app.
  21. 27.In which region of the Periodic Table would the element with the electronic structure below be located? $1s^2 2s^2 2p^6 3s^2 3p^6 3d^{10} 4s^2 4p^6 4d^6 5s^2$
    • A. Group 6
    • B. Noble gases
    • C. S block
    • D. D block
    Answer, explanation and textbook page: open in the app.
  22. 28.Which factors will influence the rate of the reaction shown below? I. The number of collisions per second II. The energy of the collisions III. The geometry with which the molecules collide
    • A. I only
    • B. II only
    • C. I and II only
    • D. I, II and III
    Answer, explanation and textbook page: open in the app.
  23. 29.How many bonds are present in ?
    • A. One
    • B. two
    • C. three
    • D. four
    Answer, explanation and textbook page: open in the app.
  24. 30.Which pair of monomers forms polyesters?
    • A. Difunctional alcohol, difunctional organic acid
    • B. Difunctional alcohol, difunctional amino acid
    • C. Ethylene, ethylene
    • D. Amino acid, amino acid
    Answer, explanation and textbook page: open in the app.
  25. 31.Which changes will increase the amount of at equilibrium? −197kJ I. Increasing the temperature II. Decreasing the volume III. Adding a catalyst
    • A. I only
    • B. II only
    • C. I and II only
    • D. I, II and III
    Answer, explanation and textbook page: open in the app.
  26. 32.Which compound is a carboxylic acid?
    • B. CH COOH 3 (CH CO) O 3 2 (CH 3 3 (CH )2CHOOCH O 3 2 )
    Answer, explanation and textbook page: open in the app.
  27. 33.The mechanism of a reaction is shown below. (slow) 2OH + 2H O →4H O − 3 + 2 (fast) (fast) What is the rate law based on this mechanism? − 2 −
    • A. Rate = k[HOOH] [I ]
    • B. Rate = k[HOOH] [I ] −2
    • C. Rate = k[HOOH] [I ]
    • D. Rate = k[HOOH]
    Answer, explanation and textbook page: open in the app.
  28. 34.What is the equilibrium constant expression for the following reaction? 2 2 2
    • A. K = 1/(Hg] /([O ])
    • B. K = [Hg] [O ] 2 2 2
    • C. K = [HgO] /([Hg] [O ])
    • D. K = [2HgO]/([2Hg][O ]) 2 2
    Answer, explanation and textbook page: open in the app.
  29. 35.A triacylglycerol that is solid at room temperature is called:
    • A. Lecithin
    • B. Fat
    • C. Wax
    • D. Oil
    Answer, explanation and textbook page: open in the app.
  30. 36.Which compound is an ester?
    • A. $\mathrm{CH_3COOH}$
    • B. $\mathrm{CH_3OC_2H_5}$
    • C. $\mathrm{C_2H_5CHO}$
    • D. $\mathrm{HCOOCH_3}$
    Answer, explanation and textbook page: open in the app.
  31. 37.How many moles of sodium hydroxide are present in 2.5L of 0.5M aqueous solution?
    • A. 0.2
    • B. 0.5
    • C. 1.25
    • D. 12.5
    Answer, explanation and textbook page: open in the app.
  32. 38.Which species CANNOT act as a Lewis acid?
    • A. $\mathrm{NH_3}$
    • B. $\mathrm{BF_3}$
    • C. $\mathrm{Fe^{2+}}$
    • D. $\mathrm{AlCl_3}$
    Answer, explanation and textbook page: open in the app.
  33. 39.Which of the following statements is true?
    • A. A universal indicator is a mixture of indicators that will give a different colour for a different PH.
    • B. Phenolphthalein is a universal indicator.
    • C. A universal indicator can only be used in either strongly acidic or basic solution.
    • D. The colour of a universal indicator is red in a weak acid.
    Answer, explanation and textbook page: open in the app.
  34. 40.Three acids, HA, HB, HC have the following $K_a$ values. $K_a(\mathrm{HA}) = 1 \times 10^{-5}$ $K_a(\mathrm{HB}) = 2 \times 10^{-5}$ $K_a(\mathrm{HC}) = 1 \times 10^{-6}$ What is the correct order of increasing acid strength (weakest first)?
    • A. HA, HB, HC
    • B. HC, HB, HA
    • C. HC, HA, HB
    • D. HB, HA, HC
    Answer, explanation and textbook page: open in the app.
  35. 41.If the solute-solvent interactions are greater than the solute-solute and solvent-solvent interactions, what will be the total vapour pressure of the solution?
    • A. Greater than that calculated from Raoult's law
    • B. Less than that calculated from Raoult's law
    • C. The same as calculated from Raoult's law
    • D. Raoult's law cannot be applied for such interactions.
    Answer, explanation and textbook page: open in the app.
  36. 42.For which conversion is an oxidizing agent required?
    • A. $2\mathrm{H}^+\,(\mathrm{aq}) \rightarrow \mathrm{H}_2\,(\mathrm{g})$
    • B. $2\mathrm{Br}^-\,(\mathrm{aq}) \rightarrow \mathrm{Br}_2\,(\mathrm{aq})$
    • C. $\mathrm{SO}_3\,(\mathrm{g}) \rightarrow \mathrm{SO}_4^{2-}\,(\mathrm{aq})$
    • D. $\mathrm{MnO}_2\,(\mathrm{s}) \rightarrow \mathrm{Mn}^{2+}\,(\mathrm{aq})$
    Answer, explanation and textbook page: open in the app.
  37. 43.What volume of 0.500M NaOH is required to neutralize 25.0 mL of 1.2 ? (Assume complete ionization of the acid).
    • A. 60mL
    • B. 90mL
    • C. 100mL
    • D. 120mL
    Answer, explanation and textbook page: open in the app.
  38. 44.A gas is confined to a cylinder under constant atmospheric pressure. When the gas undergoes a particular chemical reaction, it releases $135\text{kJ}$ of heat to its surroundings and does $63\text{kJ}$ of P-V work on its surroundings. What are the values of $\Delta H$ and $\Delta E$ for the process?
    • A. $\Delta H = 135\text{kJ}, \Delta E = 63\text{kJ}$
    • B. $\Delta H = -135\text{kJ}, \Delta E = -63\text{kJ}$
    • C. $\Delta H = 135\text{kJ}, \Delta E = 198\text{kJ}$
    • D. $\Delta H = -135\text{kJ}, \Delta E = -198\text{kJ}$
    Answer, explanation and textbook page: open in the app.
  39. 45.The oxidation numbers of nitrogen in $\mathrm{NH_3}$, $\mathrm{HNO_3}$ and $\mathrm{NO_2}$ are respectively.
    • A. -3, -5, +4
    • B. +3, +5, +4
    • C. -3, +5, -4
    • D. -3, +5, +4
    Answer, explanation and textbook page: open in the app.
  40. 46.Which statement about the following reaction is correct?
    • A. 26.6kJ of energy are released for every mole of Fe reacted.
    • B. 26.6kJ of energy are absorbed for every mole of Fe reacted.
    • C. 53.2kJ of energy are released for every mole of Fe reacted.
    • D. 13.3kJ of energy are absorbed for every mole of Fe reacted.
    Answer, explanation and textbook page: open in the app.
  41. 47.The two standard electrode potentials involved in the nickel cadmium rechargeable cell are given below. NiO (s) + 2H S (l) + 2e →Ni(OH) (s) + 2OH 2 2 − 2 −E = 0 +0.49V Cd(OH) (s) + 2e →Cd(s) + 2OH (aq) 2 − E = 0 −0.76V Calculate the ?G0 in kJ of the cells.
    • A. -184
    • B. -153
    • C. -241
    • D. -206
    Answer, explanation and textbook page: open in the app.
  42. 48.Which of the following is a synthetic rubber produced from caprolactam (CPL)?
    • A. Nylon 6, 10
    • B. Terylene
    • C. Teflon
    • D. Nylon6
    Answer, explanation and textbook page: open in the app.
  43. 49.Which of the following reaction is NOT a redox reaction?
    • A. $\mathrm{Ag^+ (aq) + Cl^- (aq) \rightarrow AgCl (s)}$
    • B. $\mathrm{2Na (s) + Cl_2 (g) \rightarrow 2NaCl (s)}$
    • C. $\mathrm{Mg (s) + 2HCl (aq) \rightarrow MgCl_2 (aq) + H_2 (g)}$
    • D. $\mathrm{Cu^{2+} (aq) + Zn (s) \rightarrow Cu (s) + Zn^{2+} (aq)}$
    Answer, explanation and textbook page: open in the app.
  44. 50.The half-reaction for formation of magnesium metal upon electrolysis of molten $\mathrm{MgCl_2}$ is: $\mathrm{Mg^{2+}+2e^- \rightarrow Mg}$ What is the mass of magnesium formed upon passage of a current of $60.0\,\mathrm{A}$ for a period of $2.00\times10^3\,\mathrm{S}$?
    • A. 5.0g
    • B. 10.0g
    • C. 15.1g
    • D. 30.2g
    Answer, explanation and textbook page: open in the app.
  45. 51.An aqueous solution is 70% nitric acid ( ) by mass. What is the concentration of expressed in molality?
    • A. 0.559m
    • B. 8.62m
    • C. 11.1m
    • D. 37.0m
    Answer, explanation and textbook page: open in the app.
  46. 52.Which of the following is a natural polymer?
    • A. Polythene
    • B. Polysaccharides
    • C. Nylon
    • D. Terylene
    Answer, explanation and textbook page: open in the app.
  47. 53.What is the ionization energy of an iron atom if it requires a radiation of $276\,\text{nm}$ to completely remove its outer most electron in the gaseous state? (Plank's constant, $h=6.626\times10^{-34}\,\text{Js}$, speed of light, $c=3\times10^8\,\text{ms}^{-1}$)
    • A. $7.21\times10^{-19}\,\text{J}$
    • B. $7.21\times10^{-19}\,\text{kJ}$
    • C. $7.21\times10^{19}\,\text{J}$
    • D. $7.21\times10^{19}\,\text{kJ}$
    Answer, explanation and textbook page: open in the app.
  48. 54.Which of the electron configurations describes the ground state electron configuration of $\mathrm{Cl^-}$?
    • A. $1s^2 2s^2 2p^6 3s^2 3p^6$
    • B. $1s^2 2s^2 2p^6 3s^1$
    • C. $1s^2 2s^2 2p^6 3p^1$
    • D. $1s^2 2s^2 2p^6 3s^2 3p_x^2 3p_y^1$
    Answer, explanation and textbook page: open in the app.
  49. 55.When 0.68 is divided by 14.364, the actual answer is 0.0473405. What will be the correct answer?
    • A. 0.05
    • B. 0.047
    • C. 0.0473
    • D. 0.04734
    Answer, explanation and textbook page: open in the app.
  50. 56.What is the correct molecular electronic configuration for the molecular ion, ?
    • A. [option image did not render in the source capture]
    • B. [option image did not render in the source capture]
    • C. [option image did not render in the source capture]
    • D. [option image did not render in the source capture]
    Answer, explanation and textbook page: open in the app.
  51. 57.Which of the following molecules or ions will exhibit delocalized bonding? , , NH 4 + N 3 − NH 4 + N 3 −
    • A. and
    • B. and NO 2 − NO 2 − NH 4 +
    • D. and
    Answer, explanation and textbook page: open in the app.
  52. 58.Based on molecular orbital theory, the bond orders of $\mathrm{H_2}$, $\mathrm{H_2^+}$ and $\mathrm{H_2^-}$ are, respectively.
    • A. 1, 0, and 0
    • B. 1, 1/2, and 0
    • C. 1, 0, and 1/2
    • D. 1, 1/2, and 1/2
    Answer, explanation and textbook page: open in the app.
  53. 59.How many 3d electrons are present in the ground state of chromium atom?
    • A. 4
    • B. 5
    • C. 6
    • D. 10
    Answer, explanation and textbook page: open in the app.
  54. 60.When the following substances are arranged in order of increasing melting point (lowest melting point first), the correct order is:
    • A. ,
    • B. , , CH CH CH 3 2 3 CH COCH CH CH OH 3 33 2 2 CH CH CH 3 2 3 CH CH CH OH 3 2 2 CH COCH 3 3 CH
    • C. , ,
    • D. , , 3 3 CH COCH OH 3 2 2 CH CH CH 3 2 3 CH CH CH OH 3 2 2 CH CH CH 3 2 3 CH CH CH COCH 3 3
    Answer, explanation and textbook page: open in the app.
  55. 61.The half-life for the first order decomposition of nitromethane, $\mathrm{CH_3NO_2}$, at 500k is 650 seconds. If the initial concentration of $\mathrm{CH_3NO_2}$ is 0.500M, what will its concentration be (M) after 1300 seconds have elapsed?
    • A. 0.125
    • B. 0.140
    • C. 0.250
    • D. 0.425
    Answer, explanation and textbook page: open in the app.
  56. 62.In a zero-order reaction for every rise of temperature, the rate is doubled. If the temperature is increased 10 C 0 100 C 0 from to , the rate of the reaction will become
    • A. 64 times
    • B. 128 times
    • C. 256 times
    • D. 512 times
    Answer, explanation and textbook page: open in the app.
  57. 63.Which of the following mathematical relationships between $K$, $K_1$ and $K_2$ is correct? $\mathrm{CO_2(g) + H_2(g) \rightleftharpoons CO(g) + H_2O(g)}\quad K$ $\mathrm{Fe(s) + CO_2(g) \rightleftharpoons FeO(s) + CO(g)}\quad K_1$ $\mathrm{Fe(s) + H_2O(g) \rightleftharpoons FeO(s) + H_2(g)}\quad K_2$
    • A. $K = K_1 + K_2$
    • B. $K = K_1 \times K_2$
    • C. $K = K_1/K_2$
    • D. $K = K_2/K_1$
    Answer, explanation and textbook page: open in the app.
  58. 64.The value of for the following equilibrium reaction is 4.0 at a temperature of 373k. What mass of ethyl ester ( ) would be present in the equilibrium mixture if 15g of acetic acid and 11.5 g of ethanol were mixed and equilibrium was established at this temperature?
    • A. 5.2g
    • B. 10.1g
    • C. 12.6g
    • D. 22g
    Answer, explanation and textbook page: open in the app.
  59. 65.Which one of the following is true about an open system?
    • A. A system that exchanges both energy and matter with its surroundings.
    • B. A system that cannot exchange both matter and energy with its surroundings.
    • C. A system that only exchanges matter with its surroundings
    • D. A system that only exchanges energy with its surroundings
    Answer, explanation and textbook page: open in the app.
  60. 66.Which of the following statements is true about the percent ionization of a weak acid?
    • A. It decreases with increasing concentration
    • B. It increases with decreasing concentration
    • C. It increases with increasing concentration
    • D. It decreases with decreasing concentration
    Answer, explanation and textbook page: open in the app.
  61. 67.What is the value of for the reaction ?
    • B. −1013kJ −223kJ +223kJ +1013kJ
    Answer, explanation and textbook page: open in the app.
Which of these compounds is the ester formed from the reaction of acetic acid and 1-Propanol? [Figure: The four options are scanned images of condensed structural formulae rather than typed text; each is labelled with its letter to the left of the image. A: 'CH3CO' written on the main line, with a double bond drawn vertically upward from the carbon of CO to an O, and a single bond drawn vertically downward from the same carbon to 'OCH2CH2' written on the line below. B: 'CH3CH2COH' on the main line, with a double bond drawn vertically upward to an O above the C, and a single bond drawn downward from beneath the CH2 to 'OCH2CH2' on the line below. C: 'CH3CH2CH2OCH2' on the main line, with a double bond drawn vertically upward from the final CH2 carbon to an O, and a single bond drawn downward from beneath the second CH2 to 'OCH2CH2' on the line below. D: 'CH3COCH2CH2CH' on a single line, with a double bond drawn vertically upward from the second carbon (the C of CO) to an O.
  1. 68.This is the ticked option.]
    • A. [structural formula image - see figure_description]
    • B. [structural formula image - see figure_description]
    • C. [structural formula image - see figure_description]
    • D. [structural formula image - see figure_description]
    Answer, explanation and textbook page: open in the app.
  2. 69.A lab instructor is preparing 5.0 liters of a $0.10\mathrm{M}$ $\mathrm{Pb(NO_3)_2}$ (molecular mass 331) solution. What is the mass required?
    • A. 165.5g of $\mathrm{Pb(NO_3)_2}$ and add 5.0kg of $\mathrm{H_2O}$
    • B. 165.5g of $\mathrm{Pb(NO_3)_2}$ and add $\mathrm{H_2O}$ until the solution has a volume of 5.0 liters.
    • C. 33.1g of $\mathrm{Pb(NO_3)_2}$ and add $\mathrm{H_2O}$ until the solution has a volume of 5.0 liters.
    • D. 33.1g of $\mathrm{Pb(NO_3)_2}$ and add 5.0 liters of $\mathrm{H_2O}$.
    Answer, explanation and textbook page: open in the app.
  3. 70.Which of the following is NOT a characteristic of the electrolytic cell containing aqueous solution of NaCl used in the manufacture of sodium hydroxide?
    • A. The sodium hydroxide solution is produced in the electrolytic cell.
    • B. The electrolyte must be a dilute solution of NaCl
    • C. Hydrogen is produced at the cathode.
    • D. The production of chlorine gas occurs at the anode
    Answer, explanation and textbook page: open in the app.
  4. 71.The kinetic data are for the reaction: $\mathrm{A+B\rightarrow C}$ [A] | [B] | Initial rate ($\mathrm{mol\,dm^{-3}\,s^{-1}}$) 0.1 | 0.1 | $1\times10^{-5}$ 0.1 | 0.2 | $4\times10^{-5}$ 0.2 | 0.1 | $1\times10^{-5}$ From these data what are the orders of the reaction with respect to A and B?
    • A. Order of A = 1 order of B = 0
    • B. Order of A = 0 order of B = 2
    • C. Order of A = 0 order of B = 4
    • D. Order of A = 1 order of B = 2
    Answer, explanation and textbook page: open in the app.
  5. 72.Which of the following metals has the highest electrical and thermal conductivities of any metal?
    • A. Ag
    • B. Cu
    • C. Ni
    • D. Co
    Answer, explanation and textbook page: open in the app.
  6. 73.Which of the following is the most important source for the extraction of iron?
    • A. Hematite
    • B. Bauxite
    • C. Chalcopyrite
    • D. Sphalerite
    Answer, explanation and textbook page: open in the app.
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