IB Chemistry Higher Level

1. What is the number of carbon atoms in 12 g of ethanoic acid CH3COOH, Mr = 60? A. 0.20 B. 2.0 C. 1.2 × 1023 D. 2.4 × 1023

2. Which of these molecular formulae are also empirical formulae? I. C2H6O II. C2H4O2 III. C5H12 A. I and II only B. I and III only C. II and III only D. I, II and III

Turn over 3. Which volume of ethane gas, in cm3, will produce 40 cm3 of carbon dioxide gas when mixed with 140 cm3 of oxygen gas, assuming the reaction goes to completion? 2C2H6 (g) + 7O2 (g) → 4CO2 (g) + 6H2O (g) A. 10 B. 20 C. 40 D. 80

4. What is the relative atomic mass, Ar, of an element with this mass spectrum? Mass/charge Percent abundance 25 24 0 20 40 60 80 100 26 A. 24.0 B. 24.3 C. 24.9 D. 25.0

5. Which element is in group 13? Ionization energy / kJ mol–1 1st 2nd 3rd 4th A. 789 1580 3230 4360 B. 578 1820 2750 11 600 C. 738 1450 7730 10 500 D. 496 4560 6910 9540

6. What is the correct trend going down groups 1 and 17? A. Melting points increase B. Boiling points decrease C. Electronegativities increase D. Ionization energies decrease

7. Which oxide will dissolve in water to give the solution with the lowest pH? A. P4O10 B. SiO2 C. Al2O3 D. MgO

8. Which of these statements are correct? I. Zinc is not a transition element. II. Ligands are Lewis bases. III. Manganese(II) chloride is paramagnetic. A. I and II only B. I and III only C. II and III only D. I, II and III

9. Which of these species contains the shortest carbon to oxygen bond length? A. CH3CH2O− B. CH3CH2OH C. CH3COO− D. CH3COOH

Turn over 10. Which molecule is most polar? A. CHF3 B. CF4 C. CClF3 D. CCl4

11. Which combination correctly describes the geometry of BrF4 −? Electron domain geometry around Br Molecular geometry around Br A. Octahedral Tetrahedral B. Tetrahedral Square planar C. Octahedral Square planar D. Tetrahedral Tetrahedral

12. Which series shows the correct order of metallic bond strength from strongest to weakest? A. Na > K > Rb > Mg B. Mg > Rb > K > Na C. Rb > K > Na > Mg D. Mg > Na > K > Rb

13. Which statement is correct? A. O3 bond dissociation occurs at a longer wavelength of light than O2 bond dissociation. B. O3 bond dissociation occurs at a higher energy than O2 bond dissociation. C. O3 bond lengths are shorter than O2 bond lengths. D. O3 bond dissociation occurs at a higher frequency of light than O2 bond dissociation.

14. Which equation shows the enthalpy of formation, ∆Hf, of ethanol? A. 2C (s) + 3H2 (g) + 1 2 O2 (g) → C2H5OH (g) B. 4C (s) + 6H2 (g) + O2 (g) → 2C2H5OH (g) C. 2C (s) + 3H2 (g) + 1 2 O2 (g) → C2H5OH (l) D. 4C (s) + 6H2 (g) + O2 (g) → 2C2H5OH (l)

15. Which statements about bond strength and activation energy are correct for this reaction? CH4 (g) + 2O2 (g) → CO2 (g) + 2H2O (l) ∆H Ö = −891 kJ Relative bond strength Relative magnitude of activation energy, Ea A. products < reactants forward > reverse B. products > reactants forward < reverse C. products > reactants forward > reverse D. products < reactants forward < reverse

16. Which combination gives the standard hydration enthalpy of Na+ (g)? kJ mol–1 ∆H Ö lattice NaCl (s) +790 ∆H Ö solution NaCl (s) +4 ∆H Ö hydration Cl− (g) −359 A. 4 + 359 + 790 B. 4 + 359 − 790 C. −4 − 359 + 790 D. 4 − 359 + 790

Turn over 17. Which reaction becomes more spontaneous as temperature increases? A. CaCO3 (s) → CaO (s) + CO2 (g) B. N2 (g) + 3H2 (g)  2NH3 (g) C. 3CO2 (g) + 4H2O (g) → C3H8 (g) + 5O2 (g) D. SO2 (g) + H2O2 (l) → H2SO4 (l)

18. Which apparatus can be used to monitor the rate of this reaction? CH3COCH3 (aq) + I2 (aq) → CH3COCH2I (aq) + H+ (aq) + I− (aq) I. A pH meter II. A gas syringe III. A colorimeter A. I and II only B. I and III only C. II and III only D. I, II and III

19. Which change does not increase the rate of this reaction? CuCO3 (s) + H2SO4 (aq) → CuSO4 (aq) + H2O (l) + CO2 (g) A. Increasing the particle size of the CuCO3 B. Increasing the temperature C. Increasing the concentration of H2SO4 (aq) D. Stirring the reaction mixture

20. What are the units of the rate constant, k, if the rate equation is Rate = k [A][B]2? A. mol dm−3 s−1 B. dm3 mol−1 s−1 C. dm6 mol−2 s−1 D. dm9 mol−3 s−1