5SO2(g) + 2KMnO4(aq) + 2H2O(l) → K2SO4 + 2MnSO4(aq) + 2H2SO4(aq)
In the reaction above, the products give a
- A. purple solution
- B. purple precipitate
- C. colourless precipitate
- D. colourless solution
If the heat of combustion of hydrogen is -285.8kJ,
What is the heat of formation of water?
- A. +571.6 kJ
- B. -571.6 kJ
- C. -285.8 kJ
- D. +285.8 kJ
Na2CO3(g) + 2HCl(aq) → 2NaCl(aq) + H2O(l) + CO2(g)
How many moles of sodium trioxocarbonate (IV) are there in a 25 cm3 solution which required 10cm3 of 0.05 mol dm-3 hydrochloric acid solution to neutralize it?
- A. 1.000 mole
- B. 0.100 mole
- C. 0.010 mole`
- D. 0.111 mole
In the electrolysis of CuSO4(g) using platinum electrodes, the reaction at the anode is
- A. 4H+ + 4e- → 2H2
- B. 4OH- + 4e- → 2H2O + O2
- C. 2OH - 2e- → 2OH
- D. 2OH- + 2OH- → 2H2O + O2
In which of the following is the oxidation number of sulphur equal to -2?
- A. SO3
- B. S8
- C. H2S
- D. SO2
The solution that will conduct the highest amount of electricity is?
- A. 0.5 mol dm-3 of hydrochloric acid
- B. 2.0 mol dm-3 of hydrochloric acid
- C. 0.5 mol dm-3 ethanoic acid
- D. 2.0 mol dm-3 ethanoic acid
Zinc and carbon rods are used as anode and cathode respectively in a
- A. Leclanche cell
- B. lead accumulator
- C. Daniel cell
- D. voltaic cell
H2(g) + Br2(g) → 2HBr(g)
The above reaction is carried out at 25oC. ΔH is -72 kJ mol-1 and ΔS is – 106 J mol-1K-1, the reaction will?
- A. not proceed spontaneously at the given
- B. proceed spontaneously at the given temperature
- C. proceed in the reverse direction at the given temperature
- D. proceed spontenously at lower temperature
Trioxonitrate (V) acid is not used for preparing hydrogen gas from metals because it
- A. is strongly oxidizing
- B. is volatile
- C. renders the metal passive
- D. forms a layer of oxide on the metal
The ion that can be used as an oxidizing agent is
- A. Au3+
- B. Fe3+
- C. ClO-
- D. Ca2+
2C2H2(g) + 5O2(g) → 4CO2(g) + 2H2O(g)
In the reaction above, the mass of carbon(IV)oxide produced on burning 78 g of ethyne is
[C =12, O = 16, H = 1]
- A. 264 g
- B. 39 g
- C. 352 g
- D. 156 g
If 30cm3 of gas at 50oC is warmed to 80o at a fixed pressure, the fractional increase in volume is
- A. 0.009
- B. 0.093
- C. 0.910
- D. 1.090
The idea of planetary electron was that of
- A. Rutherford
- B. Thompson
- C. Bohr
- D. Dalton
The order in which a mixture of sand, ammonium chloride and sodium chloride can be separated is
- A. dissolution → dryness → filtration → evaporation
- B. filtration → sublimation → evaporation → dryness
- C. sublimation → dissolution → filtration → evaporation
- D. dissolution → filtration → sublimation → evaporation
A decrease in atomic size and an increase in nuclear charge across a period lead to
- A. an increase in the tendency to lose electron
- B. an increase in chemical reactivity
- C. a decrease in electropositivity
- D. a decrease in covalency in bond formation
The element with the electron configuration 1s22s22p3 is
- A. calcium
- B. chlorine
- C. oxygen
- D. nitrogen
What is the molar mass of a substance, if 0.4 mole of the substance has a mass of 25.0g?
- A. 62.5 g
- B. 40.0 g
- C. 6.3 g
- D. 2.5 g
Nuclear fission involves the splitting of a heavy element into two nuclei of
- A. nearly equal masses with a relaese of energy and radiaton
- B. equal masses with a relaese of energy
- C. equal masses with a release of energy and radiation
- D. unequal masses without any relaese of energy
The volume of 2.5 moles of oxygen at s.t.p is
[Molar volume of a gas at s.t.p = 22.4 dm3]
- A. 50.0 dm3
- B. 84.0 dm3
- C. 28.0 dm3
- D. 56.0 dm3
A difference between chemical and physical change is that in a chemical change
- A. oxygen is consumed
- B. heat is supplied
- C. a reversible process oocurs
- D. a new substance is formed
A particle that contains 11 protons, 12 neutrons and 10 electrons is probably a
- A. neutral non-metal
- B. metallic ion
- C. non-metallic ion
- D. neutral metal