Pipe-borne water is usually chlorinated in order to
- A. improve the teste of the water
- B. remove the hardness in the water clear
- C. coagulate sediments in the water
- D. kill harmful bacteria in the water
- E. make the water clear and colourless
Substances which absorb water from the atmosphere without dissolving in it are sid to be
- A. anhydrous
- B. hygroscopic
- C. insolube
- D. hydrated
- E. efflorescent
How many electrons are removed from Cr2- when it is oxidized to CrO42-?
- A. o
- B. 2
- C. 4
- D. 8
- E. 10
What mass of copper would be deposited by a current of 1. 0 ampere passing for 965 seconds through copper (ll) tetraoxosulphate (IV) solution? [Cu = 63.5; 1F = 96500C]
- A. 0.318g
- B. 0.635g
- C. 18g
- D. 6.35g
- E. 9.65g
Which of the following will produce oxygen and hydrogen during its electrolysis using platinum electrode?
- A. Glucose solution
- B. Aqueous copper (ll) tetraoxosulphate (IV)
- C. Dilute sodium chloride solution
- D. Concentrated hydrochloric acid
- E. Dilute copper (ll) chloride solution
What is the function of sulphur (IV) oxide in the reaction represented by the following equation? SO 2(aq) + 2H2S(g) → 3S (s) + 2H 2O (l)
- A. Dehydrating agent
- B. Oxidising agent
- C. Bleaching agent
- D. Acid
- E. Precipitant
Which of the following methods is suitable for the preparation of an insoluble salt?
- A. Action of an acid on a metal
- B. Double decomposition
- C. Neutralisation
- D. Action of an acid on a trioxocarbonate (IV)
- E. Action of an acid on an oxide
Which of the following is not a property of trioxonitrate (V) salts?
- A. Positive reaction to the brown ring test
- B. Ability to dissolve in cold water
- C. Decomposition on being strongly heated
- D. Production of effervescence with saturated Na2CO3 solution
- E. Evolution of gas with concentrated H2SO4 and copper turnings
The following oxides react with water except
- A. Na2O
- B. SO3
- C. NO2
- D. CO2
- E. CuO
AN AQUEOUS SOLUTION IS ACIDIC IF
- A. its pH value is high
- B. it s corrosive
- C. it changes the colour of litmus
- D. it has a bitter taste
- E. it contains more H3O- than OH-
What is the basicity of the acid in the followed reaction? NaCO + 2CHCOOH → 2CH COONa + H2O + CO2
- A. 1
- B. 2
- C. 3
- D. 4
- E. 8
A mixture of NaCI(s) and CaCO3(s) is best separated by
- A. dissolution followed by filtration
- B. sublimation followed by crystallization
- C. dissolution followed by evaporation
- D. dissolution followed by crystallization
- E. sublimation followed by dissolution
What volume of oxygen at s.t.p would react with carbon to form 4.40g of CO2 according to the following equation? C(s) + O2(g) → CO2(g) [O = 16; C =12; 1 mole of a gas occupies 22.4dm3 at s.t.p]
- A. 0.224dm3
- B. 2.24dm3
- C. 4.40dm3
- D. 4.48dm3
- E. 22.4dm3
Boyle’s law can be expressed mathematically as
- A. V \(\alpha\) T (P constant)
- B. P \(\alpha\) V (T constant)
- C. P \(\alpha\) T
- D. V \(\alpha\) 1 / p(T constant)
- E. V1/T1 = / T2
Which of the following Group 1 elements has the highest ionization energy?
- A. 55Cs
- B. 37Rb
- C. 19K
- D. 11Na
- E. 3Li
Which of the following statements is correct about sodium chloride in the solid state?
- A. it exists as aggregates of ions
- B. it conducts electricity
- C. its melting point is below 100oC
- D. it exists as discrete molecules
- E. its ions are linked by metallic bonds
The valence electrons of element 12Mg are in the
- A. 1s orbital
- B. 2s orbital
- C. 2px orbital
- D. 2py orbital
- E. 3s orbital
Element X, with electronic configuration 2, 8, 2 and element Y with electronic configuration 2, 8, 7 are like to combine by
- A. metallic bonding
- B. covalent bonding
- C. electrovalent bonding
- D. dative bonding
- E. hydrogen bonding
If an element R belongs to the same group as sodium, an aqueous solution of ROH will
- A. be neutral
- B. be acidic
- C. be coloured
- D. have pH greater than 7
- E. turn back litmus red
An atom 17 protons, 17 electrons and 18 neutrons has a mass number of
- A. 17
- B. 18
- C. 34
- D. 35
- E. 52
Lead and tin are the components of
- A. steel
- B. bronze
- C. brass
- D. dentist amalgam
- E. soft solder