Which of the following compounds is a base?
- A. CO2
- B. CaO
- C. H3PO3
- D. CH3COOCH3
A few drops of concentrated HCI are added to about 10cm3 of a solution of pH 3.4. The pH of the resulting mixtures is?
- A. less than 3.4
- B. greater than 3.4
- C. unaltered
- D. the same as that of pure water
Which of the following atoms represents deuterium?
- A. No protons = 1, No of neutrons = 0, No of electrons = 0
- B. No protons = 1, No of neutrons = 0, No of electrons = 1
- C. No protons = 1, No of neutrons = 1, No of electrons = 1
- D. No protons = 1, No of neutrons = 2, No of electrons = 1
The solubility, in moles per dm3 of 20.2 g of potassium trioxonitrate (V) dissolve in 100 g of the resulting mixture is?
(K = 39, O = 16, N =14).
- A. 0.10
- B. 0.20
- C. 1.00
- D. 2.00
Sodium chloride has no solubility product value because of its?
- A. saline nature
- B. high solubility
- C. low solubility
- D. insolubility
A major effect of oil pollution in coastal waters is the?
- A. destruction of marine life
- B. desalination of the water
- C. increase in the acidity of the water
- D. detoxification of the water
A solid that absorbs water from he atmosphere and forms an aqueous solution is?
- A. hydrophilic
- B. efforescent
- C. deliquescent
- D. hygroscopic
Element X, Y and Z belong to a groups I, V and VII respectively. Which of the following is TRUE about the bond types of XZ and YZ3?
- A. Both are electrovalent
- B. Both are covalent
- C. XZ is electrovalent and YZ3 is covalent
- D. XZ is covalent and YZ3 is electrovalent
Which of the following physical properties decreases down a group in the periodic table?
- A. Atomic radius
- B. Ionic radius
- C. Electropositivity
- D. Electronegativity
The number of electrons in the valence shell of an element of atomic number 14 is?
- A. 1
- B. 2
- C. 3
- D. 4
An increase in temperature causes an increase in the pressure of a gas because?
- A. it decreases the number of collision between the molecules
- B. the molecules of the gas bombard the walls of the container more frequently
- C. it increases the number of collision between the molecules
- D. it causes the molecules to combine
The shape of ammonia molecule is?
- A. trigonal planar
- B. octahedral
- C. square planar
- D. tetrahedral
The densities of two gases, X and Y, are 0.5 g dm-3 and 2.0 dm-3 respectively.
What is the rate of diffusion of X relative to Y?
- A. 0.1
- B. 0.5
- C. 2.0
- D. 4.0
For a gas, the relative molecular mass is equal to 2Y. What is Y?
- A. The mas of the gas
- B. The vapour density of the gas
- C. The volume of the gas
- D. The temperature of the gas
To what temperature must a gas 273 K be heated in order to double both its volume and pressure?
- A. 298 K
- B. 546 K
- C. 819 K
- D. 1092 K
8g CH4 occupies 11.2 dm3 at s.t.p. What volume would 22 g of CH3CH2CH3 occupy under the same condition?
(C = 12, H = 1)
- A. 3.7 dm3
- B. 11.2 dm3
- C. 22.4 dm3
- D. 33.6 dm3
At the same temperature and pressure, 50 cm3 of nitrogen gas contains the same number of molecules as?
- A. 25 cm3 of methane
- B. 40 cm3 of hydrogen
- C. 50 cm3 of ammonia
- D. 100 cm3 of chlorine
A pure solid usually melts?
- A. over a wide range of temperature
- B. over a narrow range of temperature
- C. at a lower temperature than the impure one
- D. at the same temperature as the impure one
A mixture of sand, ammonium chloride and sodium chloride is best separated by?
- A. sublimation followed by addition of water and filteration
- B. sublimation followed by addition of water and evaporation
- C. addition of water followed by filtration and sublimation
- D. addition of water followed by crystallization and sublimation
The confirmatory test for alkanoic acids in organic qualitative analysis is the?
- A. turning of wet blue litmus paper red
- B. reaction with alkanols to form esters
- C. reaction with sodium hydroxide to form salt and water
- D. reaction with aqueous Na2COsp3 to liberate a gas which turns lime water milky
Which of the following represents saponification?
- A. Reaction of carboxylic acids with sodium hydroxide
- B. Reaction of alkanoates with acid
- C. Reaction of alkanoates with alcohols
- D. Reaction of alkanoates with sodium hydroxide