The electronic configuration 1s2 22s 22p 63s23p 6 is that of a
- A. noble gas
- B. Group ll element
- C. Group lll element
- D. Group V element
- E. Group VI element
A sample of orange juice is suspected to have been contaminated with a yellow dye. Which of the following methods can be used to detect the dye?
- A. Decantation
- B. Chromatography
- C. Distillation
- D. Filtration
- E. Evaporation
Which of the following reaction will not take place under normal conditions?
- A. Zn(s) + 2HCl → ZnCI2(aq) + H 2(g)
- B. Fe (s) + H 2SO4(aq) → FeSO4(aq) + H2(g)
- C. Cu (s) + 2HCI (aq) → CuCI 2(aq) + H2(g)
- D. Ca(s) + 2H 2O (1) → Ca(OH)2(g) + H2(g)
- E. 2Na(s) + 2H 2O (1) → 2NaOH(aq) + H2(g)
Catalytic hydrogenation of oils results in the production of
- A. soaps
- B. detergents
- C. alkanes
- D. butter
- E. margarine
What is the voltage of the cell represented at Zn(s) Zn 2+(aq) /Cu2+(aq) /Cu(s) given that for Cu 2+(aq)/ Cu (s) Eo = 0.337V and for Zn2+(aq) /Zn(s)’ E o = -0.763V?
- A. +0.426V
- B. -0.426V
- C. -0.337V
- D. -1.10V
- E. +1.10V
The oxidation number of chlorine is + 1 in
- A. KCIO 3
- B. CI 2O 7
- C. ZnCI2
- D. HCI
- E. NaCIO
50cm 3 of a saturated solution of potassium trioxonitrate (V)at 40°C contains 5.05g of the salt. What is the solubility of potassium trioxonitrate (V) at 40°C? (KNO3 = 101)
- A. 1.0 mol dm-3
- B. 1.5 mol dm-3
- C. 2.0 mol dm-3
- D. 2.5mol dm-3
- E. 5.0mol dm-3
Which of the following is a condition for a spontaneous reaction?
- A. ∆H -T is zero
- B. ∆H-T∆ S is positive
- C. ∆H-T∆ S is negative
- D. ∆S is zero
- E. ∆S is positive
The electronic configuration of two atoms X and Y are as follows: X – 1s 2 2s 22p 63s 1, Y -1s 22s 22p 63s23p 64s 2 which of the statements below is true of the position of X and Y in the Periodic Table?
- A. x belongs to group 1, Y belongs to period 2,
- B. x belongs to group 1, Y belongs to period 4
- C. x belongs to group 2, Y belongs to period 1
- D. x belongs to group 3, Y belongs to period 2
- E. x belongs to group 3, Y belongs to period 4
What quantity of copper will be deposited by the same quantity of electricity that deposited 9.0g of aluminum? (A = 27, Cu = 64)
- A. 64g
- B. 32g
- C. 7.1g
- D. 6.4g
- E. 3.2g
Which of the following statements is not true of tin? it
- A. is a p-block element
- B. is extracted from cassiterite SnO 2
- C. is used for protecting iron containers from corrosion
- D. combines with copper to form the alloy brass
- E. shows two oxidation states, + 2 and + 4 in most of its compounds
The following are s-block elements except
- A. lithium
- B. magnesium
- C. potassium
- D. calcium
- E. aluminium
Given that for the reaction. N2(g) + 3H2(g) ⇌ 2NH3(g) ∆H = -92kJ. What is the enthalpy of formation of ammonia from its elements?
- A. -46KJ mol -1
- B. -184KJmol -1
- C. -92KJmol -1
- D. 184KJmol -1
- E. +46KJmol -1
If sulphur is dissolved in carbon (IV) sulphide and the solution is allowed to evaporate, the allotrope of sulphur formed is
- A. plastic sulphur
- B. amorphous sulphur
- C. rhombic sulphur
- D. monoclinc sulphur
- E. colloidal sulphur
If sulphur is dissolved in carbon (IV) sulphide and the solution allowed to evaporate the allotrope of sulphur formed is
- A. plastic sulphur
- B. amorphous sulphur
- C. rhombic sulphur
- D. monoclinc sulphur
- E. colloidal sulphur
Given that 1 mole of carbon -12 weighs 12.0g, how many atoms are there in 24.0g magnesium? (C = 12, Mg = 24, NA = 6.02 x 10 23mol-1)
- A. 1/2 x 6.02 x 10 23
- B. 1 x 6.02 x10 23
- C. 2 x 6.02 x 10 23
- D. 3x 6.02 x 10 23
- E. 4x 6.02 x 10 23
Which of the following is used extensively in manufacturing photographic chemicals?
- A. Aluminium chloride
- B. Zinc chloride
- C. Silver chloride
- D. Mercury (ll) chloride
- E. lron (ll) chloride
Given the following half-cell reaction; 2Cl(aq) → CI2(g) + 2e, how many mole of electrons will be required to produce 1.12dm3 of chlorine gas at s.t.p? (Molar volume of a gas at s.t.p. = 22.4dm 3)
- A. 1.00
- B. 0.40
- C. 0.20
- D. 0.10
- E. 0.01
Octane number is highest in petrol containing a high proportion of
- A. heptane
- B. octane
- C. 2-methylpentane
- D. 2, 4-dimethylpentane
- E. 2,2,4-trimethylpentane
The rate of the hydrogen in the reaction Zn(s) + 2HCI (aq) → ZnCI 2(g) + H 2(aq) + H 2(g) can be increased by
- A. using Zinc powder instead of Zinc granules
- B. using dilute instead of concentrated hydrochloric acid
- C. cooling the container in which the mixture is placed
- D. using an alloy of zinc instead of pure zinc
- E. using hydrogen chloride gas instead of hydrochloric acid solution
Why is potassium fluoride added to the electrolyte in the extraction of sodium from fused sodium chloride?
- A. Pure sodium chloride does not conduct electricity
- B. Potassium fluoride prevents the sodium produced from attacking the electrodes
- C. Potassium fluride increases conductivity
- D. Potassium fluride reduces the temperature at which sodium chloride fuses
- E. the potassium fluride acts as a catalyst