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CHEMISTRY 2021 UTME PAST QUESTION

1. The hydrolysis of proteins by dilute mineral acids produces

A. Sucrose
B. lucose
C. mino acids
D. atty acids

2. Which of the following oxides causes acids rain?

A. CO
B. O
C. 2O2
D. O2

3. The ratio of carbon atoms to hydrogen atoms in a hydrocarbon is 1:2, if its molecular mass is 56, what is its molecular formula?

A. C3H6
B. 4H8
C. 2H4
D. H2

4. What is the relative molecular mass of the compound below?
[H=1.0 C=12.0 O=16.0]

A. 137
B. 36
C. 4
D. 9

5. Catholic protection of metals is based on

A. Standard electrode potential of hydrogen
B. ts electrical conductivity
C. ature of oxides formed
D. elative tendencies of oxidation

6. If humid air Is polluted by chlorine discharge, air can be restored by sprinkling

A. Solid MnO2
B. cidified KMnO4
C. cidified FeSO4
D. aturated NaCl(aq)

7. The alkanol represented by the structure below is

A. Primary and dihydric
B. econdary and monohydric
C. ertiary and dihydric
D. econdary and dihydric

8. Which of the following Pairs of compounds would form a precipitate when their aqueous solutions are mixed?

A. NaCl and KNO3
B. CL and NaNO3
C. 2SO4 and BaCl2
D. H4NO3 and Na2CO3

Study the graphs below and use them to answer questions 9 to 11.

9. Which of the graphs illustrates the variation of the rate of evolution of a gas from given length of magnesium ribbon (y-axis) with increase in the concentration of the acid added (x-axis)?

A. I
B. I
C. II
D. V

10. Which of the graphs illustrates the variation of the pH of a given volume of strong acid solution (x-axis) with the volume of strong base titrated against it (r-axis)?

A. I
B. II
C. III
D. IV

11. Which of the graphs illustrates the variation of the solubility of a salt in water (y-axis), If the dissolution process is exothermic?

A. I
B. II
C. III
D. IV

12. The formation of ethene from the dehydration of ethanol can be described as

A. An addition reaction
B. An elimination reaction
C. An oxidation reaction
D. A substitution reaction

13. Which of the following gases is highly soluble in water at room temperature?

A. Ammonia
B. Carbon (IV) oxide
C. Chlorine
D. Nitrogen

14. A molecule of phosphorus is

A. Diatomic
B. Triatomic
C. Tetratomic
D. Double decomposition

15. The most common method of preparing insoluble salts is by.

A. Filtration
B. Decomposition
C. Neutralization
D. Double decomposition

16. What is the moles of oxygen would exert a pressure of 10 atm at 320K in an 8.2 dm2 cylinder? [R=0.082 atm dm3 mol-1 K-1].

A. 0.32
B. 1.56
C. 3.13
D. 31.25

17. The basic property of salts used as drying agents is

A. Efflorescence
B. High melting point
C. Hygroscopy
D. Low solubility

18. What would be observed when aqueous ammonia is added in drops and then in excess to solution of copper (II) ions?

A. Blue precipitate is formed which is soluble in excess ammonia
B. Brick red precipitate is produced which is insoluble in excess ammonia
C. White precipitate is formed which is soluble in excess ammonia
D. green precipitate is formed which is soluble in excess ammonia

19. When CuSO4(aq) is added to Pb(NO3)2(aq).

A. There would be no visible changes
B. A blue precipitate would be formed
C. The resulting solution would become colorless
D. White precipitate would be formed

20. Consider the structure below:

How many carbon atoms does the percent chain contain?

A. 5
B. 4
C. 3
D. 2

21. Under which conditions of pressure (P) and temperature (T) would the volume of an inflated balloon increase? When

A. Both T and P are increased
B. Both T and P are decreased
C. T is increased and P is decreased
D. T is decreased and P is increased

22. The collision between ideal gas molecules is considered to be perfectly elastic because

A. They collide without losing energy
B. They move randomly in straight line
C. Their average kinetic energy is variable
D. The distance between them is large compared to their sizes

23. Elements with high ionization energies would

A. Lose electrons easily
B. Both T and P are decreased
C. Has high effective nuclear charges
D. Has low atomic numbers

24. Which of the following statements about Group VII elements is correct?

A. They are present in the same physical state
B. They are strong reducing agents
C. Their reactivity decreases down the group
D. They exist as monoatomic molecules

Consider the diagram below and use it to answer questions 25 and 26

25. Which of the following cell notations represent the diagram?

A. B2+/B//A/A3+
B. A3+/A//B/B2+
C. B/B2+//A/A3+
D. A/A3+//B2+/B

26. Which of the following half reaction equations represent the reaction at the cathode?

A. A3+(aq) + 3e-→A(s)
B. B2+(aq)+ 2e-→B(s)
C. A(s)→A3+(aq) + 3e-
D. B(s)→B2+(aq) + 2e-

27. The reactivity of fluorine is high because of

A. Its high electronegativity
B. The small size of the fluorine atom
C. The availability of d-orbitals
D. The strong F-F bond

28. How many coulombs of electricity would liberate 1.08g of Ag from a solution of silver salt? [AG=108.0;1F=96500C]

A. 96500C
B. 9650C
C. 965C
D. 9.65C

29. The Bohr model of the atom proposed the existence of

A. The nucleus
B. Electron shells
C. Nucleons
D. Neutrons

30. At 25℃, evaporation of a 100 cm3 solution of K2CO3 to dryness gave 14 g of salt. What is the solubility of K2CO3 at 25℃?[K2CO3 = 138].

A. 0.01mol dm-3
B. O.101 mol dm-3
C. 1.01mol dm-3
D. 10.0mol dm-3

31. Student X titrated 25cm3 of Na2CO3 with 0.1 moldm-3 HCL , using methyl orange as indicator. Student Y carried out the same exercise but used phenolphthalein as indicator. Which of the following statement about the titration is true?

A. Hydrogen chloride gas was released in the reactions in both titrations
B. The titre values obtained from the equations are equal
C. The titre value obtained by X is twice that of Y
D. The titre value obtained by Y is twice that of X

32. What is the concentration of a solution which contains 0.28g of potassium hydroxide in 100cm3 of solution? [KOH = 56]

A. 0.001moldm-3
B. 0.05moldm-3
C. 0.10moldm-3
D. 0.50moldm-3

33. What is the empirical formula of hydrocarbon containing 0.160moles of hydrogen?

A. CH2
B. CH3
C. CH4
D. C2H4

34. Which of the species has the largest ionic radius?

A. S2-
B. Cl-
C. K+
D. Ca2+

35. Which of the following statement is correct about ionization energy?

A. Decreases across the period
B. Results in the formation of anion
C. Causes metallic nuclei to disintegrate
D. Decreases down the group

36. Potassium trioxonitrate(V) can be obtained from its solution by?

A. Distillation
B. Evaporation
C. Crystallization
D. Filtration

37. An element, Q, contains 69.09% of 63Q and 31% of 65Q. What is the relative atomic mass of Q?

A. 63.0
B. 63.6
C. 65.0
D. 69.0

38. The following ions have the same electronic configuration except 8O, 12Mg, 13Al, 17Cl.

A. Cl-1
B. O2-
C. Mg2+
D. Al3+

39. The region around the nucleus where electrons can be located is called

A. Spectra
B. An orbital
C. A quanta
D. A field

40. Protons and electrons are called fundamental particles because they?

A. Are indivisible
B. Have different charges
C. Are the lightest particles
D. Are found in all matters

Consider the following energy profile diagram and use it to answer question 41-43

The activation energy of the reaction is

A. EA
B. EB
C. EC
D. ED

42. The enthalpy change of the reaction is?

A. EA
B. EB
C. EC
D. ED

43. The energy profile diagram illustrates

A. An endothermic reaction.
B. An exothermic reaction
C. A spontaneous reaction
D. A redox reaction.

44. How many moles of oxygen would occupy a volume of 22.4 cm3 at s.t.p.? [Molar volume at s.t.p.=22,400 cm3, Avogadro’s number=6.02×1023]

A. 3.01×1020
B. 3.01×1027
C. 6.02×1019
D. 6.02×1027

45. The isotopes of neon are represented by the symbols x20Ne, y21Ne, and z22Ne. The relationship between x, y and z is?

A. X>Y> Z
B. XY< Z
C. X=Y=Z
D. X

46. Which of the following pairs of molecules forms hydrogen bonds?

A. C2H5OH and CH3OH
B. CH3OH and H2
C. CH2S and CH4
D. NH3 and SO2

47. Which of the following statement about elements in Group VII is correct?

A. Br will oxidize Cl-
B. F2 has the least tendency of to be reduced
C. Cl2 will oxidize I
-1
D. L2 is a stronger oxidizing agent than F2

48. Electrovalent compounds normally

A. Have low boiling points
B. Have mobile electrons
C. Conducts electricity in the solid state
D. Dissolve in polar solvents.

49. A coordinate covalent bond could be formed between

A. NH3 and PCl3
B. BCl3 and AlCl3
C. BCl3 and NH3
D. H+ and AlCl3

50. Which of the following scientist discovered the electron?

A. Joseph J. Thompson
B. James Chadwick
C. Amedeo Avogadro
D. Ernest Rutherford.