The gas that gives brown colouration in brown ring test is
- A. NO
- B. CO2
- C. NO2
- D. CO
Steam changes the colour of anhydrous cobalt (II) chloride from
- A. blue to pink
- B. white to red
- C. white to green
- D. blue to white
The property which makes alcohol soluble in water is the
- A. boiling point
- B. hydrogen bonding
- C. ionic character
- D. covalent nature
The furring of kettles is caused by the presence in the water of?
- A. Calcium tetraoxosulphate (VI)
- B. Calcium hydrogentrioxocarbonate (IV)
- C. Calcium hydroxide
- D. Calcium trioxocarbonate (IV)
The substance least considered as a source of environmental pollution is
- A. Lead compounds
- B. Organophosphorous compounds
- C. Silicate minerals
- D. Uranium
25cm\(^3\) of a 0.2 mol dm\(^3\) solution of Na\(_2\)CO\(_3\) requires 20 cm\(^3\) of a solution of HCl for neutralization. The concentration of the HCl solution is
- A. 0.5 mol dm3
- B. 0.6 mol dm3
- C. 0.2 mol dm3
- D. 0.4 mol dm3
Three drops of a 1.0 mol dm-3 solution of NaOH are added to 20 cm3 of a solution of pH 8.4. The pH of the resulting solution will?
- A. Close to that of pure water
- B. Unaltered
- C. Greater than 8.4
- D. Less than 8.4
When a salt loses its water of crystallization to the atmosphere on exposure, the process is said to be
- A. Efflorescence
- B. Deliquescence
- C. Effervescence
- D. Fluorescence
Tetraoxosulphate (VI) acid burns the skin by
- A. Hydrolysis
- B. Hydration
- C. Heating
- D. Dehydration
The solubility of a salt of molar mass 101g at 20oC is 0.34 mol dm-3. If 3.40g of the salt is dissolved completely in 250cm3 of water in a beaker, the resulting solution is
- A. A suspension
- B. Saturated
- C. Unsaturated
- D. Supersaturated
The product of the electrolysis of dilute sodium hydroxide using platinum electrodes are
- A. Hydrogen and oxygen gases
- B. Water and hydrogen gas
- C. Water and sodium metal
- D. Sodium metal and oxygen gas
Cu\(_2\)S(s) + O\(_2\)(g) โ 2CU(s) + SO\(_2\)(g)
What is the change in the oxidation number of copper in the reaction above?
- A. +1 to 0
- B. 0 to +2
- C. +2 to +1
- D. 0 to +1
When dissolved in water, NaOH flakes show
- A. An endothermic change
- B. An exothermic change
- C. A slow reaction
- D. A rapid reaction
The Arrhenius equation expresses the relationship between the speed of a reaction and its
- A. Molecular collision
- B. Heat of reaction
- C. Catalyst
- D. Activation energy
When H\(_2\)S is passed into a solution of iron (III) chloride, the solution turns
- A. Pale green
- B. Pale red
- C. Brown
- D. Colourless
PCl5(g) โ PCl3(g) + Cl2(g)
In the reaction above, a decrease in pressure will
- A. Decelerate the reaction
- B. Increase the yield of PCl3
- C. Increase the yield of PCl5
- D. Accelerate the reaction
Which of the following equations show that a reaction is in equilibrium?
- A. ฮG < O
- B. ฮG = ฮH โ TฮS
- C. ฮG > O
- D. ฮG = O
What amount of mercury would be liberated if the same quantity of electricity that liberates 0.65g of zinc is applied?
- A. 2.01g
- B. 1.00g
- C. 4.02g
- D. 8.04g
In the reaction E+F โ G+H, the backward reaction is favoured if the concentration of
- A. F is increased
- B. E is increased
- C. E is reduced
- D. G is reduced
Which of the following gases contains the least number of atoms at s.t.p?
- A. 1 mole of butane
- B. 3 mole of ozone
- C. 4 mole of chlorine
- D. 7 mole of argon
The chromatography separation of ink is based on the ability of the components to
- A. React with solvent
- B. React with each other
- C. Dissolve in each other in the column
- D. Move at different speeds in the column