The substance often used for vulcanization of rubber is
- A. chlorine
- B. hydrogen peroxide
- C. sulphur
- D. tetraoxosulphate (IV) acid
A phenomenon where an element exist in different forms in the same physical state is known as
- A. isomerism
- B. amorphism
- C. allotropy
- D. isotopy
For a reaction in equilibrium, the species involved in the equilibrium constant expression are
- A. gaseous and solid species
- B. liquid and solid species
- C. solid and dissolved species
- D. gaseous and dissolved species
N2(g) + O2(g) โ 2NO(g); ฮH = + 180.6 kJ mol-1
In the reaction above, increase in temperature will
- A. increase the quantity of N2
- B. increase in the yield of NO
- C. decrease the yield of NO
- D. decrease the quantity of O2
Powdered marble reacts faster with hydrochloric acid solution than the granular form because the powdered form has
- A. more molecules
- B. more atoms
- C. larger surface area
- D. relatively large mass
0.46g of ethanol when burned raised the temperature of 50g of water by 14.3K. Calculate the heat of combustion of ethanol.
[C = 12, O = 16, H = 1, Specific heat capacity of water = 4.2 jg-1K-1]
- A. +3000 KJ mol-1
- B. +300 KJ mol-1
- C. -300 KJ mol-1
- D. -3000 KJ mol-1
Given that M is the mass of substance deposited in an electrolysis and Q the quantity of electricity consumed, then Faraday’s law can be written as
- A. M = Z/Q
- B. M = Q/Z
- C. M = Z/2Q
- D. M = QZ
(1/2)Zn2+(aq) + e- โ (1/2) Zn(s)
In the reaction above, calculate the quantity of electricity required to discharge zinc.
[F = 96 500 C mol-1]
- A. 0.965 x 104C
- B. 4.820 x 104C
- C. 9.650 x 104C
- D. 48.200 x 104C
MnO\(_{4(aq)}^{-1}\) + 8H\(^+ _{(aq)}\) + Y โ Mn\(^{2+} _{(aq)}\) + 4H\(_2\)O\(_{(l)}\)
Y in the equation above represents
- A. 2e-
- B. 3e-
- C. 5e-
- D. 7e-
The pOH of a solution of 0.25 mol dm-3 of hydrochloric acid is
- A. 12.40
- B. 13.40
- C. 14.40
- D. 14.60
In which order are the following salts sensitive to light?
- A. Agl > AgCl > AgBr
- B. AgCl > Agl > AgBr
- C. AgBr > AgCl > Agl
- D. AgCl > AgBr > Agl
HCl(aq) + H\(_2\)O(l) โ H\(_3\)O+(aq) + Cl\(^-\)(aq)
In the reaction above, Cl\(^-\)(aq) is the
- A. conjugate acid
- B. acid
- C. conjugate base
- D. base
Hydration of ions in solution is associated with
- A. absorption of heat
- B. reduction of heat
- C. conduction of heat
- D. liberation of heat
1.0 dm3 of distilled water was used to wash 2.0g of a precipitate of AgCl. If the solubility product of AgCl is 2.0 x 10\({^-10}\)moldm-6, what quantity of silver was lost in the process?
- A. 2.029 * 10-3mol dm-3
- B. 1.414 * 10-3mol dm-3
- C. 2.029 * 10-5mol dm-3
- D. 1.414 * 10-5mol dm-3
Water molecule can be ligands especially when they are bonded to
- A. alkaline earth metals
- B. alkali metals
- C. transition metals
- D. group VII elements
A side effect of soft water is that
- A. it gives offensive taste
- B. excess calcium is precipitated
- C. it attacks lead contained in pipes
- D. it encourages the growth of bacteria
The noble gas, argon,is used for
- A. electric arc welding
- B. welding brass
- C. underwater welding
- D. steel welding
The distance between the nuclei of chlorine atoms in a chlorine molecule is 0.194 mm. The atomic radius of chlorine atom is
- A. 0.097 mm
- B. 0.194 mm
- C. 0.388 mm
- D. 2.388 mm
The shapes of CO\(_2\), H\(_2\)O and CH\(_4\) respectively are
- A. bent, linear and tetrahedral
- B. bent, tetrahedral and linear
- C. linear, bent and tetrahedral
- D. tetrahedral, linear and bent
The knowledge of half-life can be used to
- A. create an element
- B. detect an element
- C. split an element
- D. irradiate an element