Chemistry — 2008
WASSCE · 44 questions · Answers included
44 questions
The mass spectrometer can be used to measure mass of
Find the number of neutrons in an atom represented by 45 21 X.
The valence electrons in a chloride ion are [ 17 CI]
What is the atomic number of an element whose cation Y + has the electronic configuration 1s 2 2s 2 2p 6 ?
Atom \(^{234} _{88} Q\) decay by alpha emission to give an atom R. The atomic number and mass number of atom R are respectively
Which of the following statements is not true of halogens?
Elements in the same group of the periodic table have
Consider the following elements and their electronic configurations W: 1s 2 2s 2 X: 1s 2 2s 2 2p 6 Y: 1s 2 2s 2 2p 6 3s 2 Z: 1s 2 2s 2 2p 6 3s 2 3p 2 . Which of the elements belong to the same group in the periodic table?
Arrange the following elements in order of increasing electron affinity: Br 2 CI 2 I 2 F 2
Water molecules are held together by
The force of attraction between covalent molecules is?
What is the mass of 6.02 x 10 24 atoms of magnesium? [Mg = 24, Avogadro constant = 6.02 x 10 23 atoms mol -1 ]
Which of the following compounds with the corresponding masses contain the highest percentage of nitrogen? [N = 14]
Which of the following compounds with the corresponding masses contain the highest percentage of nitrogen? [N = 14]
If 5.00cm 3 of 0.20 mol dm -3 Na 2 CO 3 was diluted with distilled water to obtain 250 cm 3 solution, what is the concentration of the resulting solution?
Consider the reaction represented by the following equation: Zn (s) + 2HCI (aq) → ZnCI 2(aq) + H 2(g) what volume of hydrogen gas is produced at s.t.p. when 3.25 g of zinc reacts with excess dilute HCI? [Zn = 65, Molar gas volume at s.t.p. = 22.4 dm -3 ]
Which of the following gases has the lowerst rate of diffusion under the same conditions of temperature and pressure? [H = 1, O = 16, Ne = 20, CI = 35]
In a fixed volume of a gas, an increase in temperature results in an increase in pressure due to an increase in the
When concentrated \(H_2SO_4\) is added to NaCI (s), the gas evolved
The collision theory proposes that
Diamond does not conduct electricity because it?
Which of the following set of equations could be used to represent the standard enthalpy of formation of glucose?
The colour of phenolphthalein indicator in dilute HNO is
An aqueous solution of CaCI 2 is
Which of the following compounds would dissolved in water to give a solution whose pH is less than 7?
Consider the reaction represented by the question below: KOH (aq) + HCI (aq) → KCI (aq) + H 2 O (l) What volume of 0.25 mol dm -3 KOH would be required to completely neutralize 40 cm 3 of 0.10 mol dm -3 HCI?
When 100 cm 3 of a saturated solution of KCIO 3 at 40 o C is evaporated, 14 g of the salt is recovered what is the solubility of KCIO 3 at 40 o C? [KCIO 3 = 122.5]
The high solubility of ethanol in water is due to its
Consider the equilibrium reaction represented by the equation: 2SO 2(g) + O 2(g) ⇌ 2SO 3(g) ∆H = - 197 kJmol -1 . At equilibrium, increase in the total pressure of the system brings about
In dry Leclanche cell, manganese (IV) oxide acts as
Oxidation takes place at the anode during electrolysis because the anode
Calculate the quantity of electricity passed when 0.4 A flows for 1 hour 20 minutes through an electrolytic cell
A mixture of kerosene and diesel oil can be separated by
Which of the following compounds would not give a precipitate with ammoniacal AgNO3 solution?
When ethanol is heated with excess concentrated tetraoxosulphate (VI) acid, the organic product formed is
The hydrolysis of groundnut oil by potassium hydroxide is known as
What is the main type of reaction alkenes undergo?
Arrange the following compounds in order of increasing boiling point l.CH\(_3\)CH\(_2\)CH\(_2\)OH II.CH\(_3\)CH\(_2\)OH III.CH\(_3\)CH\(_2\)CH\(_2\)CH\(_2\)OH IV.CH\(_3\)CH\(_2\)CH\(_2\)CH\(_2\)CH\(_3\)
A hydrocarbon containing 88.9% carbon has the empirical formula [H = 1 C = 12]
A solution of a salt was acidified with HCI when a few drops of BaCI 2 solution were added, a white precipitate was formed. Which of the following anions is present in the salt?
Which of the following substances causes the depletion of the ozone layer in the atmosphere?
Chemicals that are produced in small quantities and with very high degree of purity are
Aluminium is a good roofing material because it
Which of the following alloys is mainly used in making statues?