1s2, 2s2, 2p6, 3s2, 3p6, 3d7, 4s2
An element with the electronic configuration above is a
- A. non-metal
- B. metal
- C. transition element
- D. group two element
The method that can be used to convert hard water to soft water is
- A. chlorination
- B. passage over activated charcoal
- C. the use of an ion-exchange resin
- D. aeration
Nitrogen obtained from the liquefaction of air has a higher density than that obtained from nitrogen containing compounds because the former contains
- A. water vapour
- B. oxygen
- C. carbon (IV) oxide
- D. rare gases
In order to remove one electron from a 3S orbital of gaseous sodium atom, about 496KJMol-1 of energy is required. This energy is referred to as
- A. electron affinity
- B. ionization energy
- C. activation evergy
- D. electronegativity
In which of the following are water molecules in the most disorderly arrangement?
- A. Ice at -10°C
- B. Ice at 0°C
- C. Water at 100°C
- D. Steam at 100°C
A gaseous metallic chloride MClx consists of 20.22% of M by mass. The formula of the chloride is?
[M = 27, Cl = 35.5]
- A. MCl
- B. MCl2
- C. MCl3
- D. M2Cl6
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
From the equation above, the mass of magnesium required to react with 250cm3 of 0.5M HCl is
[Mg = 24]
- A. 0.3g
- B. 1.5g
- C. 2.4g
- D. 3.0g
Which of the following will have its mass increased when heated in air?
- A. Helium
- B. Magnesium
- C. Copper pyrites
- D. Glass
Which is the temperature of a given mass of a gas initially at 0°C and 9 atm, if the pressure is reduced to 3 atm at constant volume?
- A. 91K
- B. 182K
- C. 273K
- D. 819K
Which of the following gases will diffuse fastest when passed through a porous plug?
[H = 1, C = 12, N = 14, O = 16]
- A. Propane
- B. Oxygen
- C. Methane
- D. Ammonia
56.00cm3 of a gas at S.T.P. weighed 0.11g. What is the vapour density of the gas?
[Molar volume of a gas at S.T.P = 22.4dm3]
- A. 11.00
- B. 22.00
- C. 33.00
- D. 44.00
200cm3 each of 0.1M solutions of lead (II) trioxonitrate(V) and hydrochloric acid were mixed. Assuming that lead (II) chloride is completely insoluble, calculate the mass of lead (II) chloride that will be precipitated.
[Pb = 207, Cl= 35.5, N = 14, O = 16]
- A. 2.78g
- B. 5.56g
- C. 8.34g
- D. 11.12g
Which of the following substances would you see as an indicator in the titration of sodium carbonate solution against hydrochloric acid (complete neutralisation)?
- A. Litmus paper
- B. Phenolphthalein
- C. Methyl orange
- D. Universal indicator
- E. None of these
You are provided with five gas jars containing SO2, CO2, H2, CO and NO respectively. Select a test from A to E which will identify ANY ONE of the gases completely
- A. pass each gas into lime water
- B. pass each gas into water and test with litmus paper
- C. pass each gas into concentrated sulphuric acid
- D. expose each gas to atmospheric air
- E. expose each gas to fumes of hydrogen chloride
A gas jar was inverted over burning yellow phosphorus floating over water in a beaker. After burning, the water level was found to rise in the gas jar. The water level rises because
- A. pressure inside the gas jar is greater than pressure outside it
- B. the air in the gas jar had been used up by burning
- C. oxygen in the gas jar had been used up by burning
- D. nitrogen in the gas jar had been used up by burning
- E. the temperature in the jar had risen considerably
In titration involving sodium hydroxide and dilute hydrochloric acid, where would you place the base?
- A. in the beaker
- B. in the conical flask
- C. in a burette
- D. in the standard flask
- E. in the measuring cylinder
By means of filtration, one component can be obtained pure from an aqueous mixture of sodium chloride and?
- A. potassium nitrate
- B. sand
- C. lead nitrate
- D. sugar (glucose)
- E. starch
Which of the following changes is physical?
- A. Adding iron filing to aerated water
- B. Adding sodium metal to water
- C. Cooling a solution of Iron (II) sulphate to obtain the hydrated salt
- D. Cooling water to obtain ice
- E. Burning the domestic gas (Utilgas) for cooking
If hydrogen sulphide gas is passed into a solution of a pure iron chloride, a yellow deposit appears. If the deposit is filtered, a pale green solution is left behind. The pale green solution is
- A. dilute sulphuric acid
- B. dilute hydrochloric acid
- C. unreacted hydrogen sulphide in water
- D. iron (III) chloride
- E. Iron (II) chloride
Consider the following equation H2O + 2Fe2+ + Cl2 ↔ 2Fe3+ + 2Cl- + H2O. Which behaves as an oxidizing agent?
- A. Fe2+
- B. Cl2
- C. Fe3+
- D. Cl-
- E. H2O
Two gas cylinders contain ethylene (ethene) and acetylene respectively. One test which can be used to distinguish between them is by?
- A. passing each gas through bromine water
- B. passing each gas through dilute potassium permanganate solution
- C. passing each gas through silver nitrate solution
- D. treating each gas catalytically with excess hydrogen gas