Waec Chemistry Past Questions

Question 1451

Consider the following table

Substitute	Meltig point / ºC	Boiling point / ºC
P	- 78	-25
Q	- 8	40
R	- 6	150
S	44	280

Which of the substances is a liquid at room temperature and rapidly evaporates on exposure to air?

A. P
B. Q
C. R
D. S

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Question 1452

Which of the following sketches is a graphical representation of Boyle's law?

A. A
B. B
C. C
D. D

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Question 1453

Which of the following scientists formulated the law of conservation of mass?

A. A. Lavoisier
B. J. Dalton
C. R. Boyle
D. J. Proust

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Question 1454

The first definition of an element was made by

A. J. Dalton.
B. A. Lavoisier.
C. R. Boyle.
D. J. J. Thompson.

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Question 1455

A reaction is represented by the equation below. A_2(g) + B_2(g) 2AB_(g); ∆H = +X kJmol^-1 Which of the following statements about the system is correct?

A. The reaction goes to completion at equilibrium
B. The forward reaction is exthermic
C. At equilibrium increase in temperature favours the reverse reaction
D. Pressure has no effect on the equilibrium mixture

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