2023 WAEC (WASSCE) Chemistry Past Questions

If $y = 23_{five} + 101_{three}$, find y, leaving your answer in base two

1. A.1110
2. B.10111
3. C.11101✓ Correct
4. D.111100

A boy estimated his transport fare for a journey as N190 instead of N200. Find the percentage error in his estimate

1. A.95%✓ Correct
2. B.47.5%
3. C.5.26%
4. D.5%

Convert 3510 to number in base 2

1. A.1011✓ Correct
2. B.10011
3. C.100011
4. D.11001

Select two stages of booting from the following list: i. Power on Self Test; ii.  Loading of Operating System;  iii.  Loading of e-mails; iv.  Start in safe mode. iv. Save all active files

1. A.A. I and II only✓ Correct
2. B.B. I and III only
3. C.C. II and IV only
4. D.D. III and IV only

When ammonium trioxocarbonate (IV) solution is added to separate solutions of calcium, zinc and sodium salt precipitate could be formed in the case of

1. A.calcium only
2. B.zinc only
3. C.calcium and znic only✓ Correct
4. D.sodium and zinc only

When current flows through a moving-coil galvanometer, the force exerted on the pointer depends on the: i. strength of the current. ii. magnetic field strength. iii. length of the coil. Which of the statement(s) above is/are correct?

1. A.i only✓ Correct
2. B.ii only
3. C.i and iii only
4. D.i, ii and iii

Removing a program on a computer properly requires?

1. A.A. deleting.
2. B.B. archiving.✓ Correct
3. C.C.  disabling.
4. D.D. uninstalling.

The fixed cost of producing 100 units of a good is $600. If the variable cost is $400. the average total cost of one unit of the good is

1. A.$4
2. B.$6
3. C.$8✓ Correct
4. D.$10

In question numbered 99 above, choose the best option from letters A - D that best completes the gap.

1. A.caption
2. B.commentary
3. C.edition
4. D.feature

The road signs in the picture above indicate

1. A.A. two ways traffic ahead
2. B.B. dualised carriage ahead
3. C.C. two junctions ahead
4. D.D. two exit routes ahead✓ Correct