2018 - JAMB Chemistry Past Questions and Answers - page 6

This is because the quick-lime acts as a drying agent hence, it can dry most gases except ammonia. Consequently, it removes the water vapour. Quick-lime (calcium oxide) reacts with the carbon dioxide forming calcium carbonate. Carbon dioxide and monoxide is eliminated leaving nitrogen, and the rare gases.

A catalyst is a substance that speeds up a chemical reaction, but is not consumed by the reaction.

The setup could go like this:

A fire where the coal burns. A boiler full of water that the fire heats up to make steam. A cylinder and piston, rather like a bicycle pump but much bigger. Steam from the boiler is piped into the cylinder, causing the piston to move first one way then the other.

2NaOH + H\(_2\) SO\(_4\)↔Na\(_2\)SO\(_4\) + 2H\(_2\)O

  V x 0.5M = 2(10 x 1.25)

  0.5V = 2 x 12.5

  0.5V = 25

  V = 250.5 = 50cm\(^2\)

From the dilution law:

  C\(_1\)V\(_1\) = C\(_2\)V\(_2\)

  C\(_1\) = Initial conc. of NaOH = 0.6M

  V\(_1\) = Initial Volume of NaOH = 300cm3

  C\(_2\) = Final conc. of NaOH = 0.4M

  V\(_2\) = Final Volume of NaOH = ?

  V\(_2\) = \(\frac{C_1V_1}{C_2}\)

  V\(_2\) = \(\frac{0.6 \times 300}{0.4}\)

  V\(_2\) = 450 cm\(^3\)

Diamond is a covalent macromolecule, and typical of a covalent substance is an insulator. All valence electrons are localized in well-defined covalent bonds and hence are not free to move through the structure