Past Questions And Answers
(a) Describe the Prismatic Compass.
(b) Highlight four basic precautions that should be taken when making a compass traverse.
View Discussion (0)WAEC 2001 THEORYThe largest man-made lake in Africa is
- A. volta
- B. tana
- C. malawi
- D. kainji
(a) State two factors which can affect the rate of a chemical reaction.
(b) 0.72g of magnesium was added to different volumes of 2 mol. per dm\(^3\) hydrochloric acid. The volume of liberated was as measured at room temperature and pressure. The result of the experiment was as tabulated
| vol. of 2 mol. per dm\(^3\) HCl used (cm\(^3\) | Vol. of H\(_2\) evolved in cm\(^3\) (to the nearest 10cm\(^3\)) |
5 15 25 35 45 | 120 360 550 600 600 |
Use the data in the table to plot a graph of the volume of hydrogen liberated against the volume of acid used.
(c) From the graph in (b) above, determine the volume of: (i) hydrogen that would be produced if 50 cm\(^3\) of the acid were added to 0.72g of magnesium.
(ii) the acid which must be added to 0.72 g of magnesium to produce 480 cm\(^3\) of hydrogen;
(iii) the acid needed exactly to dissolve 0.72 g of magnesium completely.
(d) Explain your answer to (c)(iii).
(e) From your answers to (c) above, deduce the: (i) volume of the acid which will dissolve 1 mole of magnesium completely. (Mg = 24)
(ii) volume of hydrogen that would be liberated if 1 mole of magnesium dissolves completely in the acid;
(iii) equation for the reaction between magnesium and hydrochloric acid. Show clearly how you arrived at you answers
View Discussion (0)WAEC 1991 THEORYThe group of hardwoods that are suitable for railway sleepers in Nigeria is
- A. pine, fir and mahogamy
- B. mahogamy, obeche and iroko
- C. gmelina, teak and spruce
- D. obeche, mahogamy and pine
A play that moves the audience to pity and fear is a ____________
- A. Comedy
- B. Farce
- C. Pantomime
- D. Tragedy
It is observed that water will wet a clean glass because the
- A) cohesion of water to glass is stronger than the cohesion of water molecules
- B) adhesion of water molecules is weaker than the cohesion of water to glass
- C) cohesion of water to glass is weaker than the cohesion of water molecules
- D) adhesion of water molecules is stronger than the cohesion of water molecules
A formal letter to a dealer to enquire details about certain items for sale is referred to as
- A. an inquiry
- B. an invoice
- C. an order
- D. a quotation
when the price of a given product is reduced from N100 to N90, the quantity demanded increases from 50 to 60 units. From this we can conclude that the product's
- A. demand is elastic
- B. demand is inelastic
- C. demand is perfectly inelastic
- D. supply is not elastic
An important contribution of small-scale industries to the Nigerian economy is in the area of
- A. technological development
- B. foregin exchange earnings
- C. raw materials processing
- D. labour employment
Make x the subject of the formula:y = \(\frac {3x - 9c}{4x + 5d}\)
- A. x = \(\frac {(-9c - 5dy)}{4y - 3}\)
- B. x = \(\frac {-9c + 5dy}{4y - 3}\)
- C. x = \(\frac {(-9c + 5dy)}{4y - 3}\)
- D. x = \(\frac {-(9c + 5dy)}{4y - 3}\)