21.What are the possible oxidation numbers for an element if its atomic number is 17?
- A. -1 and 7
- B. -1 and 6
- C. -3 and 5
- D. -2 and 6
22.The energy change accompanying the addition of an electron to a gaseous atom is called?
- A. first ionization energy
- B. second ionization energy
- C. electron affinity
- D. electronegativity
23.The reaction between an organic acid and an alcohol in the presence of an acid catalyst s known as
- A. Saponification
- B. dehydration
- C. esterification
- D. hydrolysis
24.If 30cm3 of oxygen diffuses through a porous pot in 7 seconds, how long will it take 60cm3 of chlorine to diffuse through the same pot, if the vapour densities of oxygen and chlorine are 16 and 36 respectively?
- A. 9.3 secs
- B. 14 secs
- C. 21 secs
- D. 30.3 secs
25.The electronic configuration of the specie underlined as in the molecule H₂S is
- A. 1s²2s²2p⁶3s²3p⁶3d¹⁰4s²4p⁴
- B. 1s²2s²2p⁶3s²3p⁴
- C. 1s²2s²2p⁶3s²3p²
- D. 1s²2s²2p⁶3s²3p⁶
26.The functional group(s) of an amino acid is/are ___
- A. NH₂, COOH
- B. CnH₂ₙ₊₁, -COOH
- C. –COCl, COOH
- D. COOH, CONH₂
27.A student while trying to identify two gases labeled A and B, found that gas A is acidic to litmus paper and turn acidified potassium dichromate solution green, while gas B turns red litmus paper blue and forms dense white fume with hydrogen chloride. The correct identity of A and B respectively are
- A. CO₂ and N₂
- B. SO₂ and NH₃
- C. HCl and NH₃
- D. NO₂ and PCl₅
28.Which of the following titrations will have a solution with a pH greater than 7 at the end point (equivalence point) of the titration?
- A. Titration of sodium hydroxide with tetraoxosulphate (VI) acid.
- B. Titration of sodium trioxocarbonate (IV) with hydrochloric acid.
- C. Titration of sodium hydroxide with oxalic acid (ethanedoic acid)
- D. Titration of ammonium hydroxide and trioxonitrate (V) acid
29.9.0dm³ 0f a gas at s.t.p was subjected by means of a movable piston to two times the original pressure with the temperature being now at 364K. What is the volume of the gas in dm³ at this pressure?
30.An increase in the temperature causes an increase in the pressure of a gas because there is an increase in the
- A. average velocity of the molecules
- B. number of collisions between the molecules
- C. free mean path between each molecules and other
- D. none of the above
31.The forces holding naphthalene crystals together can be overcome when naphthalene is heated to a temperature of 354K resulting in the crystals melting. These forces are known as ___
- A. coulombic
- B. ionic
- C. covalent
- D. Van Der Waals
32.A metallic ion X²⁺ with an inert gas structure contains 18 electrons. How many protons are there in this ion?
33.The dependence of rate reaction on temperature is given by
- A. Le Chaterlier’s equation
- B. Law of mass action
- C. Arrchenius equation
- D. Rate equation
34.Which of the following gases may not be dried with concentrated sulphuric acid?
35.Metal salts of long chain fatty acids are known as
- A. Detergents
- B. double salts
- C. soaps
- D. grease
36.Cellulose and starch can be classified as one of the following
- A. Hydrocarbons
- B. sugars
- C. carbohydrates
- D. alkaloids.
37.Which of the following in NOT a redox reaction?
- A. 2HNO₂ + 2HI ----> 2H₂O + 2NO + I₂
- B. Zn + H₂SO₄ ----> ZnSO₄ + H₂
- C. BaCl₂ + 2AgNO₂ ----> AgCl₂ + Ba(NO3)₂
- D. 4FeO + O₂ ----> 2Fe₂O3
38.Which of the following processes leads to increase in entropy?
- A. mixing of a sample of NaCl and sand
- B. condensation of water vapour
- C. boiling of a sample of water
- D. cooling a saturated solution.
39.Which of the following statements is true?
- A. Most solids have low densities
- B. most gases are ionic compounds
- C. solids, like liquids and gases, do not have fixed shapes and fixed volumes.
- D. gases do not have their own shape but rather expand to fill the shapes of their containers uniformly
40.A liquid begins to boil when
- A. Its volume is slightly decreased.
- B. Its vapour pressure is lower than the external pressure
- C. Its vapour pressure equals the external pressure.
- D. Its molecules start escaping from the surface.