Past Questions And Answers
(a)(i) What is meant by the rate of a chemical reaction?
(ii) Explain in terms of the vision theory, the effect of temperature increase on reaction rate.
(b) When hydrogen peroxide is exposed to air, it decomposes
(i) Write an equation for the reaction.
(ii) Outline an experiment to illustrate that effect of a named catalyst on the rate of decomposition.
(iii) Sketch an energy profile diagram to show the effect of the catalyst on the reaction rate, given that the reaction is exothermic.
(c)(i) Explain why enthalpy data alone cannot be used to predict whether a reaction can occur spontaneously or not.
View Discussion (0)WAEC 1993 THEORYThe primary barrier to land reform in developing countries is the?
- A. frequent opposition by the landlords
- B. realization that output levels might fall
- C. fear that peasants will be cut off from credit
- D. general contentment with the present arrangement
P and Q are two linear transformations in the X-Y plane defined by
P: (x, y) → (-3x + 6y, 4x + y) and
Q: (x, y) → (2x-3y, -4x - 6y).
(a) Write down the matrices of P and Q. (b) What is the image of (-2,-3) under the transformation Q?
(c) Obtain a single transformation representing the transformation Q followed by P.
(d) Find the image of (1,4) when transformed by Q followed by P.
(e) Find the image P\(^1\) of the point (-√2,2√2) under an anticlockwise rotation of 225° about the origin.
View Discussion (0)WAEC 2021 THEORYAn agent employed to sell goods delivered to him by the principal is referred to as a
- A. special agent
- B. del credere agent
- C. factor
- D. universal agent
The subtraction below is in base seven. Find the missing number.
5 1 6 2seven
-2 6 4 4seven
--------
2 * 1 5
--------
- A. 2
- B. 3
- C. 4
- D. 5
A satellite revolving around the earth is kept on its orbit by
- A. Centripetal forces only
- B. Centripetal and frictional forces
- C. Centrifugal forces only
- D. Centripetal and centrifugal forces
When the pressure of the gas in a discharge tube is gradually lowered. I. there is a violet glow in the tube II. the glow in the tube splits into bands which get further apart. III, the glow and the bands eventually disappear and there is a green fluorescence in the tube. IV. the tube breaks into pieces. Which of the following are correct?
- A. I and II only
- B. I and III only
- C. I and IV only
- D. I, II and III only
If the force and the velocity on a system are each reduced simultaneously by half, the power of the system is
- A. doubled
- B. reduced to a quarter
- C. reduced by half
- D. constant
one of the factors affecting geographical distribution of population is
- A. high birth rate
- B. high death rate
- C. encouragement of early marriage in the rural area
- D. climate conditions of the different parts of the country
Tadpoles respire with
- A) Lungs
- B) Nostril
- C) Gills
- D) Spiracles

