Waec Chemistry 1997 Past Questions and Answers

Question 46:

• WAEC 1997

Boyle's law can be expressed mathematically as

A. V \(\alpha\) T (P constant)
B. P \(\alpha\) V (T constant)
C. P \(\alpha\) T
D. V \(\alpha\) ¹ / _p(T constant)
E. ^V1/_T1 = / _T2

Question 47:

• WAEC 1997

What volume of oxygen at s.t.p would react with carbon to form 4.40g of CO₂ according to the following equation? C_(s) + O_2(g) → CO_2(g) [O = 16; C =12; 1 mole of a gas occupies 22.4dm³ at s.t.p]

A. 0.224dm³
B. 2.24dm³
C. 4.40dm³
D. 4.48dm³
E. 22.4dm³

Question 48:

• WAEC 1997

A mixture of NaCI_(s) and CaCO_3(s) is best separated by

A. Dissolution followed by filtration
B. Sublimation followed by crystallization
C. Dissolution followed by evaporation
D. Dissolution followed by crystallization
E. Sublimation followed by dissolution

Question 49:

• WAEC 1997

What is the basicity of the acid in the followed reaction? NaCO + 2CHCOOH → 2CH COONa + H₂O + CO₂

A. 1
B. 2
C. 3
D. 4
E. 8

Question 50:

• WAEC 1997

(a) List two properties of alpha particles.
(b) X is an element which exists as an isotopic mixture containing 90% of \(^{39}_{19} X\) and 10% of \(^{41}_{19}X\).
(i) How many neutrons are present in the isotope \(^{41}_{19}X\)?
(ii) Calculate the mean relative atomic mass of X.