1.Ethanol is a liquid at room temperature but does not conduct electricity. Explain.
2.a) Distinguish between a covalent bond and a coordinate bond.
b) Draw a diagram to show bonding in an ammonium ion. (N = 7, H = 1)
3.a) Explain why the metals magnesium and aluminium are good conductors of electricity.
b) Other than cost, give two reasons why aluminium is used for making electric cables
whilemagnesium is not.
4.Explain why the boiling point of ethanol is higher than that of hexane.
(Relative molecular mass of ethanol is 46 while that of hexane is 86).
5. a) What is meant by dative covalent bond?
6. Sodium and Magnesium belong to the same period on the periodic table and both are
metals.
Explain why magnesium is a better conductor of electricity than sodium.
7. Using dots and crosses to represent electrons, draw the structures of the following:
(a) Phosphorous chloride (PCl3)
(b) Hydroxonium ion(H3O
+
)
8. Between aluminium and copper which one is a better conductor? Explain
9. Water has a boiling point of 100oC while hydrogen chloride has a boiling point of –
115oC. Explain
10. Explain why luminous flame is capable of giving out light and soot
11. When blue litmus paper is dipped in a solution of aluminium chloride it turns red.
Explain
12. Carbon and Silicon are in the same group of the periodic table. Silicon (IV) Oxide melts
at 2440oC while solid Carbon (IV) Oxide sublimes at -70oC. In terms of structure and
bonding, explain this difference
13. Element A has an atomic number of 6 and b has an atomic number of 9:
(i) Write the electron arrangements for elements Aand B
(ii) Using dot () and cross (X )diagram, show howAand Bcombine to form a
compound
14. (a) Explain why aluminium is a better conductor of electricity than magnesium
(b) Other than cost and ability to conduct, give a reason why aluminium is used for
making cables while magnesium is not
15. Explain how electrical conductivity can be used to distinguish between magnesium oxide
Andsilicon (IV) oxide