Chemistry Past Questions, Answers & Explanations For JAMB, WAEC, NECO & Post UTME - Chemistry

Chemistry Questions

Question 141:

Which of the following statements is true?

A An increase in the temperature of a given mass of gas increases the number of gas molecules
B An increase in the temperature of the gas does not affect the kinetic energy
C An increase in the pressure of the gas is proportional to the increase in volume
D A increase in the pressure of a gas is proportional to the decrease in volume at constant temperature
E A decrease in the pressure of the gas decreases the number of gas molecules present

Question 142:

the vapour density of a gas may be defined as

A The mass of a unit volume of the gas compared to an equal volume of water vapour
B The mass of a unit volume of the gas compared to an equal volume of hydrogen
C The mass of a unit volume of the gas compared to an equal volume of oxygen
D The mass of a unit volume of the gas minus the vapour pressure of water
E Two times the relative molecular mass of the gas

Question 143:

The reaction 3C(s) + 2Fe2O3(s) = 4Fe(s) + 3CO2(g): \(\Delta\)H =46.0 kJ is

Question 144:

The solution of a sample in a tube will be identified as a chloride if it gives

A A white precipitate on addition of AgNO3 and barium chloride solutions
B A white precipiate when acidified with HCI, and then AgNO3 solution added
C A white precipitate when acidified with dilute HNO3 and then AgNO3 solution added
D A white precipitate when acidified with dilute H2SO4 and then barium nitrate solution added
E A pungent smell of chlorine gas when dilute HCI and MnO2 are added

Question 145:

Hydrogenation may be effected by