Pipe-borne water is usually chlorinated in order to
- A. coagulate sediments in the water
- B. improve taste of the water
- C. kill harmful bacteria in the water
- D. make it pure
- E. remove the hardness in the water
The rate of a chemical reaction is NOT affected by one of these factors
- A. colour
- B. concentration
- C. presence of light
- D. surface area
- E. temperature
The molecular formula of ethylbutanoate is?
- A. CH5COOC26
- B. C3HCOOC2H7
- C. C3H7COOC3H7
- D. C3H7COOC4H9
- E. C3H7COOC2H5
Which of the following is a component of the car exhaust?
- A. Aluminium
- B. Calcium
- C. Iron
- D. Zinc
- E. Lead
Which of the following will Increase the rate of reaction of Chips of a metal M as shown in the equation below?
M(s)+2HC1(aq) → MCI2 (aq) + H2(g)
- A. Adding some distilled water
- B. Decreasing the temperature
- C. Diluting the hydrochloric acid
- D. Grinding the metal into powder
- E. Increasing the pressure
What is the colour of phenolphthalein indicator in a basic medium?
- A. Blue
- B. Colourless
- C. Orange
- D. Pink
- E. Yellow
\( ^{234}_{90}Th → ^{234}_{91}Pa + X \)
In the nuclear reaction above, X is
- A. \( ^0_1e \)
- B. \( ^0_{-1}e \)
- C. \( ^4_2He \)
- D. \( ^1_0n \)
- E. \( ^1_1p\)
When dust particles collide randomly in a beam of Sunlight, the phenomenon observed is known as
- A. Brownian movement.
- B. Dialysis
- C. Diffusion
- D. Osmosis
- E. Tyndall effect
The most efficient absorber of ultraviolet radiation in the atmosphere is
- A. CO2
- B. H2
- C. H2O
- D. 02
- E. O3
Chlorine atom forms Cl- by
- A. donating lone pair of electrons
- B. gaining an electron
- C. losing an electron
- D. sharing an electron
- E. sharing a lone pair of electrons.
Which of the following laws is obeyed If at constant temperature, 200cm of hydrogen at 1.5 × 10m5Nm-2pressure becomes 300cm3 at 1.0 × 105Nm-2 pressure?
- A. Avogadro’s
- B. Boyle’s
- C. Charles’
- D. Faraday’s
- E. Graham’s
The type of reaction ethyne mainly undergoes is
- A. addition
- B. carboxylation.
- C. esterification
- D. saponification
- E. substitution
What is the number of moles of NaHCO3in 250cm3 of its solution if the solution contains 8.4 g of NaHCO3 in 1 dm3 of the solution. [Na = 23, 0 = 16, C = 12, H = 1)
- A. 1
- B. 0.25
- C. 0.05
- D. 0.025
- E. 0.01
In the reaction 2H2S(g) + SO2(g) → 2H2SO(I)+3S(s)SO2is acting as _agent
- A. a bleaching
- B. a dehydrating
- C. an oxidizing
- D. a precipitating
- E. a reducing
What is the change in the oxidation number of phosphorus in the following reaction?
4P(s) + 5O2(ag) → 2P2O5(s)
- A. 0 to 2
- B. 0 to 5
- C. 4 to 2
- D. 4 to 5
- E. 4 to 10
Chlorine displaces bromine from aqueous potassium bromide because
- A. bromine is a liquid at room temperature
- B. bromine is weakly acidic.
- C. bromine has a greater atomic radius than chlorine
- D. chlorine is a stronger oxidising agent than bromine.
- E. the density of chlorine is less than the density of bromine.
The pH of water is 7.
What is the pH of orange juice?
- A. 7
- B. above 10
- C. below 2
- D. between 5.5 and 6.5
- E. between 7.5 and 8.5
Small amounts of compounds of transition metals are sometimes added to glass during manufacture in order to make the glass
- A. acquire certain colours
- B. easier to melt
- C. easier to mould
- D. little brittle
- E. more transparent
Which separation technique is routinely applied in the petroleum industry?
- A. chromatography
- B. distillation
- C. evaporation
- D. fractional crystallization
- E. fractional distillation
Which metal is extracted from bauxite?
- A. aluminium
- B. calcium
- C. copper
- D. magnesium
- E. tin
Why is tetraoxosulphate(VI) acid NOT used for making carbon dioxide from calcium carbonate? It is
- A. a dehydrating agent
- B. a strong acid
- C. an oxidising agent
- D. dibasic
- E. forms insoluble calcium tetraoxosulphate(Vl)