Waec Chemistry 1998 Past Questions and Answers

Question 26:

• WAEC 1998

A positive reaction to Fehling's test indicates the presence of

A. Strach
B. Reducing sugars
C. Oxidizing agents
D. Alkanoic acids
E. Alkanols

Question 27:

• WAEC 1998

Which of the following compounds is used as a gaseous fuel?

A. CH ₃-COO-CH_2-CH₃
B. CH _3-CH _2-CH _2-CH ₃
C. CHCI ₃
D. CH _3-CH_2-COOH
E. CH_3-C=CH

Question 28:

• WAEC 1998

Copy and complete the following table

Element	Number of Neutrons	Electronic Configuration	Group in the periodic Table
\(^{23}_{11}Na\)	---	1s\(^{2}\)2s\(^{2}\)2p\(^{6}\)3s\(^{1}\)	1
\(^4_2He\)	2	----	---
----	7	1s\(^{2}\)2s\(^{2}\)2p\(^{2}\)	----

Question 29:

• WAEC 1998

(a) State two postulates of the kinetic theory of gases.
(b) Write two chemical properties that are common to both carbon (IV) oxide and sulphur (IV) oxide.

Question 30:

• WAEC 1998

(a)(i) Arrange the following elements in the order of increasing reactivity. Iron, Lead, Magnessium, Aluminium.
(ii) Which of the following elements in (a)(i) above reacts with sodium hydroxide to give hydrogen?

(b) What property of tetraoxosulphate (VI) acid does each of the following reactions illustrate?
(I) S + 2H\(_2\)SO\(_4\) ---> 3SO\(_4\) + 2H\(_2\)O
(ii) MgO + H\(_2\)SO\(_4\) ---> MgSO\(_4\) + H\(_2\)O
(iii) C\(_{12}\)H\(_{22}\)C\(_{11}\) + H\(_2\)SO\(_4\) ---> 12C + H\(_2\)SO\(_4\) + 11H\(_2\)O