WASSCE JUNE 2008
1. The mass spectrometer can be used to measure mass of
A. atom
B. an electron
C. a proton
D. neutron
2. Find the number of neutrons in an atom represented by $_{21}^{45}X$
A. 21
B.24
C. 45
D. 66
3. The valence electrons in a chloride ion are [17Cl]
A. 2p electrons only
B. 3s and 3p electrons only
C. 3p and 3d electrons only
D. 3p electrons only
4. What is the atomic number of an element whose cation Y+ has the electronic configuration 1s2 2s2 2p6
A. 9
B.10
C. 11
D. 12
5. Atom $_{88}^{234}Q$ decay by alpha emission to give atom R. The atomic number and mass number from atom R are respectively
A.86 and 230
B. 87 and 234
C. 88 and 233
D. 90 and 238
6. Which of the following statement is not true of halogens?
A. They exists in different physical states
B They are diatomic molecules
C. Their ionic radii decrease down the group
D. their melting and boiling points increase down the group
7. Elements in the same group of the periodic table have
A. the same number of valence electrons
B. the same number of electrons shells
C. different chemical behaviour
D. the same atomic size
8. Consider the following elements and their configuration
W: 1s2 2s2
X: 1s2 2s2 2p6
Y: 1s2 2s2 2p6 3s2
Z: 1s2 2s2 2p6 3s2 3p2
Which of the elements belong to the same group in the periodic table?
A. W and X only
B. Y and Z only
C.W and Y only
D.W, Y and Z only
9. Arrange the following elements in order of increasing electron affinity: Br2, Cl, I2, F2
A. I2, Cl2, Br2 F2
B. I2, Br2, Cl2, F2
C.Cl2, I2, Br2, F2
D. Br2, Cl2 I2, F2
10. Water molecules are held together by
A. Covalent bond
B. hydrogen bond
C. ionic forces
D. Van dar waals forces
11. The compound formed by two elements X and Y with electronic configuration 1s2 2s2 2p4 and 1s2 2s2 2p6 3s2
A. XY
B. YX
C. X2Y3
D. Y2X3
12. The force of attraction between covalent molecules is
A. dative bonding
B. hydrogen bonding
C. ionic force
D. van der waals force
13. What is the mass of 6.02×1024 atom of magnesium?
[Mg =24.Avogadro constant =6.02×1023atom mol–1]
A. 240g
B. 24g
C. 2.4g
D. 0.24g
14. Which of the following compounds with the corresponding masses contain the highest percentage of nitrogen? [N=14]
A. NH3 =17
B NH4Cl =53.5
C. NH4NO3 =80
D. (NH3)2SO4 =132
15. If 5.00cm3 of 0.20 mol dm–3 Na2CO3 was diluted with distilled water to obtain 250cm3 solution. what is the concentration of the resulting solution?
A.0.004mol dm–3
B. 0.02mol dm–3
C. 0.20mol dm–3
D.0.40mol dm–3
16.Consider the reaction represented by the following equation: $Z{{n}_{(s)}}+2HC{{l}_{(aq)}}\to ZnC{{l}_{2(aq)}}+H{{ & }_{2(g)}}$
What volume of hydrogen gas is produced at s.t.p. when 3.25g of zinc react with excess dilute HCl? [Zn = 65, Molar gas volume at s.t.p = 22.4dm3]
A. 1.12dm3
B. 2.24dm3
C.4.48dm3
D. 8.96dm3
17. Which of the following gases has the lowest rate of diffusion under the same conditions of temperature and pressure? [H = 1, O =16, Ne = 20, Cl =35.5]
A. Chlorine
B. Hydrogen
C. Neon
D. Oxygen
18. In a fixed volume of gas, an increase in temperature results in an increase in pressure due to an increase in the
A. Number of collision between the gas molecules
B. Number of repulsion between the gas molecules
C. Number of the collision between the gas molecules and the walls of the container
D. kinetic energy of the gas
19. When concentrated H2SO4 added to NaCl(s), the gas evolved
A. bleaches damp blue litmus paper
B. forms a white precipitate with AgNO3(aq)
C. forms a white precipitate with BaCl2(aq)
D. turns moist red litmus paper blue
20. The collision theory proposes that
A. reactant collide more frequently to bring about reduction in the reaction rate
B. all collision of reactant are effective
C. reactant must collide with certain minimum amount of energy to form products
D. the fewer the collisions the faster the reaction rate
21. Diamond does not conduct electricity because it
A. has no free valence electrons
B. is a giant molecule
C. contains no bonded electrons
D. is a solid at room temperature
22. Which of the following set of equations could be used to represent the standard enthalpy of formation of glucose?
A. $6{{C}_{(s)}}+6{{H}_{2}}+3{{O}_{2(g)}}\to {{C}_{6}}{{H}_{12}}{{O}_{6(s)}}$
B. $6C{{O}_{2(g)}}+6{{H}_{2}}{{O}_{(l)}}\to {{C}_{6}}{{H}_{12}}{{O}_{6(s)}}+6{{O}_{2}}_{(g)}$
C. $6{{C}_{(g)}}+6{{H}_{2(g)}}+3{{O}_{2}}\to {{C}_{6}}{{H}_{12}}{{O}_{6(s)}}$
D. $6{{C}_{(g)}}+6{{H}_{2}}_{(g)}+3{{O}_{2(g)}}\to {{C}_{6}}{{H}_{12}}{{O}_{6(aq)}}$
23. The colour of phenolphthalein indicator in dilute HNO3(aq) is
A. colourless
B. orange
C. pink
D. purple
24. An aqueous solution of CaCl2 is
A. acidic solution
B. alkaline solution
C. a buffer solution
D. a neutral solution
25. Which of the following compounds would dissolve in water to give a solution whose pH is less than 7
A. Al(NO3)3
B. KNO3
C. N2O
D. NH3
26. Consider the reaction represented by the equation below:
$KO{{H}_{(aq)}}+HC{{l}_{(aq)}}\to KC{{l}_{(aq)}}+{{H}_{2}}{{O}_{(l)}}$
What volume of 0.25moldm–3KOH would be required to completely neutralize 40cm3 of 0.10mol dm–3 HCl
A. 40cm3
B.32cm3
C. 24cm3
D. 16cm3
27. When 100cm3of a saturated solution of KClO3 at 40oC is evaporated, 14g of the salt is recovered. What is the solubility of KClO3 at 40oC [KClO3 = 122.5]
A. 11.42moldm–3
B. 8.80moldm–3
C. 1.14moldm–3
D. 0.88moldm–3
28. The high solubility of ethanol in water is due its
A. low boiling point
B. low freezing point
C. covalent nature
D. hydrogen bonding
29. Consider the equilibrium reaction represented by the equation:
\[2S{{O}_{2(g)}}+O{{}_{2(g)}}\rightleftharpoons 2S{{O}_{3(g)}}\text{ }\Delta H=-197KJmo{{l}^{-1}}\]
At equilibrium, increase in the total pressure of the system of the system bring about
A. Decrease in rate of the reaction of the system
B. decrease in temperature of the system
C. increase in temperature of SO3
D. Increase in concentration of SO2
30.Consider the energy profile diagram below and use it to answer question 30 to 32
Q represents
A .activation energy
B. activated complex
C. enthalpy change
D. heat content of the reaction
31. Enthalpy change of the reaction is represented by
A. W
B. X
C. Z
D. Y
32. What type of reaction is represented by the energy diagram?
A. Endothermic
B. Exothermic
C. Redox
D. Neutralization
33. In dry Leclanche cell,manganes(IV) oxide acts as
A. a reducing agents
B. binding agents
C. catalyst
D. depolarizer
34. Oxidation takes place at the anode during electrolysis because the anode
A. is deficient in electrons
B. is deficient in protons
C. has excess electrons
D. has attraction for positive ions
35. Calculate the quantity of electricity passed when 0.4A flows for 1 hour 20 minutes through an electrolyte cell
A. 4800C
B 3840C
C. 1920C
D. 32C
36. A mixture of kerosene and diesel oil can be separated by
A. crystallization
B. distillation
C. precipitation
D. sublimation
37. Which of the following compounds would not give a precipitate with ammoniacal AgNO3 solution?
A. $C{{H}_{3}}C\equiv CCH$
B.$HC\equiv CH$
C. $C{{H}_{3}}C\equiv CH$
D. $C{{H}_{3}}C{{H}_{2}}C\equiv CH$
38. When ethanol is heated with excess concentrated tetraoxosulphate(VI) acid, the organic product formed is
A. ethanal
B. ethanoic acid
C. ethane
D. ethene
39. The hydrolysis of groundnut oil by potassium hydroxide is known as
A.. hydrogenation
B. Saponification
C. esterification
D. neutralization
40. What is the main tyoe of reaction alkenes undergo
A. Addition
B. Condensation
C. Elimination
D. Substitution
41.Arrange the following compounds in order of increasing boiling point.
I. CH3CH2CH2OH
II.CH3CH2OH
III. CH3CH2CH2
IV. CH3CH2CH2CH2CH3
A. I< II<IV<III
B.IV< III< II<I
C. I< II< III<IV
D. IV< II<I<III
42 The organic compound with the following structure represents
A. primary alkanol
B. secondary alkanol
C. tertiary alkanol
D. an alkanal
43. Consider the organiccompound X with the following structure: The complete oxidation of X gives
A. propanal
B. propanoic acid
C. propanone
D. propene
44. What is the IUPAC name of the compound with the following structure?
A. 2- methylbutene
B. 2 – methyl prop-2-ene
C. 2 – methylprop-1-ene
D. but-1-ene
45.A hydrocarbon containing88.9% carbon has the empirical formula [H=1, C= 12]
A. CH
B. CH2
C. C2H3
D. C2H5
46. A solution of a solution was acidified with HCl. When a few drop of BaCl2 solution were added, a white precipitate was formed. Which of the following anions is present in the salt?
A.$CO_{3}^{2-}$
B. $NO_{3}^{-}$
C.$SO_{4}^{2-}$
D. $SO_{3}^{2-}$
47. Which of the following substances causes the depletion of the ozone layer in the atmosphere?
A. Carbon(IV)oxide
B Chlorofluorocarbon
C. Sulphur (IV) oxide
D. Hydrocarbons
48. Chemicals that are produced in small quantities and with very degree of purity are
A. bulk chemicals
B. fine chemicals
C. heavy chemicals
D. light chemicals
49. Aluminium is a good roofing material because it
A. is strong and does not conduct heat and electricity
B.readily absorbs light
C. forms an oxide film over its surface which prevents corrosion
D. is flexible and conducts heat
50. Which of the following alloys is mainly used in making statues
A. Brass
B. bronze
C. Duralumin
D. Steel