Chemistry Past Questions and Answers

28.8 cm3 of nitrogen at 15°C is cooled to O°C at constant pressure, the new volume of nitrogen is?

A 17.4 cm3
B 14.7 cm3
C 27.3 cm3
D 31.7 cm3

Question 237:

If 48,000 coulombs of electricity are required to discharge 0.5 mole of sodium from a molten sodium chloride mass, then the number of coulombs required to discharge 2 moles of lead from molten lead (ll) chloride is?

A 48,000
B 96,000
C 192,000
D 384,000
E 576,000

Question 238:

The following compounds are given with their corresponding boiling points. Compound Boiling Point i.................................14°C ii................................24°C iii................................0°C iv................................120°C V.................................-2°C From the above information, indicate which of the following is correct?

A All the compounds are gaseous at 20 Â°C
B One of the compounds is gaseous at 20 °C
C Two of the compounds are gaseous at 20 Â°C
D Three of the compounds are gaseous at 20 Â°C
E None of the compounds is gaseous at 20 Â°C

Question 239:

The products of the reaction between dilute sulphuric acid and sodium thiosulphate crystals are?

A Na2SO4 + SO2 + O2 + H2O
B Na2SO3 + SO3 + O2 + H2O
C Na2SO4 + SO2 + S + H2O
D Na2SO4 + SO3 + S + H2O
E Na2SO4 + SO2 + H2O only

Question 240:

Which of the following is NOT a true statement of the kinetic Theory of Gases?

A The molecules move at random
B The size of molecules is negligble as compared with the volume of gas
C The molecular collisions are perfectly elastic
D Every molecule has the same kinetic energy at a particular temperature
E The average kinetic energy is proportional to the absolute temperature of the gas