Chemistry Past Questions And Answers
A positive brown ring test indicates the presence of
- A. NO3
- B. Fe3+
- C. SO2-3
- D. CU+
The condensation of two units of glucose will produce a dissacharide with the formula C12H22O11 which is
- A. sucrose
- B. maltose
- C. galactose D. mannose C. galactose
- D. mannose
(a)(i) Mention two types of bond present in the ammonium ion
(ii) Give three characteristic properties of electrovalent compounds
(iii) State. two differences between chemical reactions and nuclear reactions
(b) Two elements represented by the letters and Y have atomic numbers 9 and 12 respectively.
(i) Write the electronic configuration of X using the s,p,d, notation
(ii) To what group does Y belong in the periodic table?
(iii) Write the formula of the compound formed when X copibines with Y
(iv) Explain wily X is a good oxidizing agent
(v) State with reason, whether Y would be expected to form acidic or basic oxide
(c) Balance the following nuclear equations and identify the particles represented by X and Y.
(i) \(^{14}_6C\) \(\to\) X + \(^{14}_7N\)
(ii) \(^{14}_7C\)
Y \(\to\) \(^1_1H\) + \(^{17}_8O\)
(d) Consider the following list of substances: Carbon (IV) oxide, hydrogen, zinc, sulphier, methane, potassium and mercury. From the list above, state the:
(i) elements that are metals
(ii) compounds that are gases at room temperature
(iii) non-metals that are solids at room temperature
View Discussion (0)WAEC 2004 THEORYFlow of current in electrolytes is due to the movement of
- A) electrons
- B) Holes and electron
- C) Ions
- D) Charges
Consider the reaction represented by the following equation CaCI2(aq) + H2C2O2(aq) ⇌ CaC2O4(s) + 2HCI(aq). Which of the following would dissolve the precipitate of CaC2O4formed?
- A. Stirring the mixture vigorously
- B. Adding more calcium chloride solution
- C. lncreasing the concentration of the ethanedioic acid
- D. Adding concentrated hydrochloric acid
Elactrostatic force of attraction between sodium ion and halide ion is greatest in
- A. NaCI
- B. NaBr
- C. NaF
- D. NaI
An element used in the production of matches is
- A) nitrogen
- B) aluminium
- C) copper
- D) sulphur
An element X forms the following compounds with chlorine: XCl4, XCl3, XCl2. This illustrates the
- A) law of multiple proportions
- B) law of definite proportions
- C) law of conservation of mass
- D) law of chemical proportions
A finely divided from of a metal burns more readily in air than the rod from because the rod has
- A. higher molar mass
- B. smaller surface area
- C. protective oxide coating
- D. diferent chemical properties
Which of the following sets of metals dissolves in dilute HCl?
- A. Fe, Sn and Cu
- B. Mg, Fe and Cu
- C. Mg, Sn and Fe
- D. Cu, Mg and Sn