In which of the following equations can Le-chartelier’s principle be applied?
- A. H2(g)+S(g) → H2(g)
- B. 2H2S(g) + O2 (g) → 2H2O(l) + 2SO2(g)
- C. N2(g) +3H2(g) ⇌ 2NH3(g)
- D. NaOH(aq) +CO2(g) → Na2CO3(aq) + H2O(l)
- E. S(s) + 02(g) → SO2(g)
In which of these groups will all the substances be insoluble in water?
- A. Na2CO3, KNO3,(NH4)2C03
- B. NaHCO3, PbSO4, CaSO4
- C. K2C03, CaSO4, AgNO3
- D. PbCl2, NaCl, ZnCl2
- E. ZnCO3, BaSO4,AgCl
What is the maximum number of electrons that an f-orbital can accommodate?
- A. 2
- B. 6
- C. 7
- D. 10
- E. 14
A measure of the degree of disorderliness in a chemical system is known as the
- A. activation energy
- B. enthalpy
- C. entropy
- D. equilibrium
- E. free energy.
A substance is said to be hygroscopic when it
- A. absorbs atmospheric moisture and then goes into solution
- B. absorbs atmospheric moisture but does not go into solution
- C. changes colour
- D. is not affected by atmospheric moisture
- E. losses its water of crystallization
The electrode potential in volts of 2H\(^+\)(aq) / H\(_2\)(q) system is
- A. -2.87
- B. -2.71
- C. 0.8
- D. 1.68
- E. \( 0 \)
Chromatography is used to separate components of mixtures which differ in their rates of
- A. diffusion
- B. migration
- C. reaction
- D. sedimentation
- E. sublimation.
During the electrolysis of sodium Chloride solution, hydrogen is discharged at the carbon cathode because
- A. hydrogen ions are in greater concentration than sodium ions.
- B. hydrogen is higher than sodium in the electrochemical series.
- C. hydrogen is lower than sodium in the electrochemical series.
- D. of the nature of the electrodes.
- E. the concentration of sodium ions is greater than that of the hydrogen ion in the electrolyte.
Which of these is NOT a physical property f water?
- A. Can be used to dissolve organic substances
- B. Has a boiling point of 100 ° C
- C. Has a density of 19cm3 at 40 °C
- D. Has a freezing point of 0 ° C
- E. is neutral to litmus
The following gases are diatomic EXCEPT
- A. Fluorine
- B. Helium
- C. Hydrogen
- D. Nitrogen
- E. Oxygen
If two elements X and Z with electronic configurations 2,8.3 and2,8,6 respectively combine, the compound formed will have the formula
- A. XZ
- B. XZ2
- C. X2Z
- D. X2Z3
- E. X3Z2
The reaction of hydrochloric acid and calcium trioxocarbonate (IV) produces
- A. calcium chloride, carbon (IV) oxide and water
- B. calcium chloride, and trioxocarbonate (IV) acid
- C. calcium hydroxide, carbon (IV) oxide and chlorine gas
- D. calcium hydroxide, carbon (IV) oxide and water
- E. calcium metal and water.
Brownian motion explains
- A. Boyle’s law
- B. Collision theory
- C. Laws of chemical combination
- D. Molecular motion in liquids and gases
- E. Vibrational motion in liquids.
A chemical system is at equilibrium when
- A. δ G is positive
- B. δ G is zero
- C. δ S is negative
- D. δ S is positive
- E. δ S is zero.
When sodium hydroxide solution is added to a solution of zinc salt, the white precipitate formed re-dissolve in excess sodium hydroxide because
- A. sodium hydroxide is a strong alkali
- B. sodium is more reactive than zinc
- C. zinc is more reactive than sodium
- D. zinc hydroxide is amphoteric
- E. zinc hydroxide is unstable
The gas in air used by plants for photosynthesis is
- A. Argon
- B. Carbon (IV) oxide
- C. Nitrogen
- D. Oxygen
- E. Water vapour.
Which of these arrangement of elements is in order of increasing ionization energy?
- A. Boron, Carbon, Flourine, Nitrogen
- B. Boron, Carbon, Nitrogen, Flourine
- C. Carbon, Boron, Nitrogen, Flourine
- D. Flourine, Nitro9en, Carbon, Boron
- E. Nitrogen, Flourine, Carbon, Boron
The following acids are monobasic EXCEPT
- A. dioxonitrate (Ill) acid
- B. ethanedioic acid
- C. hydrobromic acid
- D. methanoic acid
- E. oxochlorate (I) acid
An element Z has a combining power of 3. Which of the following formulae is correct of its compound?
- A. ZS3
- B. ZSO3
- C. ZS04
- D. Z203
- E. Z3Cl2
Bauxite is the ore of
- A. aluminium
- B. calcium
- C. Iron
- D. sodium
- E. magnesium
Matter is neither created nor destroyed in the course of any chemical reactions is a statement of the law of
- A. combining volumes
- B. conservation of mass
- C. definite proportion
- D. multiple proportion
- E. reciprocal proportion.