- 1. 1. In which of the following separation methods does chemical reaction occur?
A) Precipitation B) Chromatography C) Sublimation D) Distillation
- 2. 2. The purity of a solid sample can best be determined by its :
A) Solubility B) Conductivity C) Melting point D) Boiling points
- 3. 3. The constituent of lead pigment can be separated by:
A) Chromatography B) Filtration C) Fractional crystallisation D) Fractional distillation
- 4. 4. Which of the following properties is not employed in the separation of a mixture?
A) Molar masses B) Boiling points C) Solubility D) Densities
- 5. 5. Ethanol is a product of fermentation of simple sugars. Which method is used to separate ethanol from the other products?
A) Boiling off the ethanol B) Fractional distillation C) Filtration D) Fractional crystallisation
- 6. 6. When a solid substance changes directly to a gas on heating without passing through the liquid state, the substance is said to have undergone:
A) Melting B) Crystallisation C) Evaporation D) Sublimation
- 7. 7. Fractional distillation is used to separate:
A) Gaseous, liquid or solid impurities from a mixture B) Liquids with different boiling points C) An insoluble substance from a soluble substance D) Substances which differ in their solubilities in a solvent
- 8. 8. A mixture of kerosene and water can be separated by:
A) Distillation B) Separating funnel C) Sublimation D) Crystallisation
- 9. 9. What is the mass number of an element if its atom contains 10 protons, 10 electrons, and 12 neutrons?
A) 20 B) 32 C) 22 D) 10
- 10. 10. The electronic configuration of an atom is 2,8,8,2. The atomic number of the element is, therefore ----------:
A) 18 B) 20 C) Z15 D) 10
- 11. 11. What is the percentage by mass of sodium in sodium hydroxide? (Na = 23, O = 16, H = 1)
A) 57.5% B) 73.0% C) 40.4% D) 42.5%
- 12. 12. What is the percentage by mass of sulphur in aluminium tetraoxosulphate (VI), Al2(SO4)_3. ( Al = 27, S = 32, O = 16)
A) 28.07% B) 21.33% C) 42.66% D) 14.71%
- 13. 13. How many electrons are in the ion F, If 19 F has neutron of 8?
A) 11 B) 8 C) 9 D) 27
- 14. 14. Calculate the formula mass of tri lead tetraoxide Pb3O4 (Pb= 207, O = 16)
A) 621 B) 586 C) 865 D) 685
- 15. 15. Calculate the formula mass of tetraoxosulphate (VI) acid H2SO4 (S= 32, H = 1, O = 16)
A) 64 B) 98 C) 40 D) 102
- 16. 16. What is the molecular mass of calcium trioxonitrate (V) Ca (NO3)_2 (Ca = 40, N = 14, O = 16)
A) 164 B) 160 C) 104 D) 146
- 17. 17. One of the following is the Avogadro's constant:
A) 6.02 × 1032 B) 6.02 × 1023 C) 6.02 × 10-23 D) 6.02 × 10-32
- 18. 18. The relative atomic mass of any element in grams contains -------- mole of atom
A) 2 B) 4 C) 1 D) 3
- 19. 19. The sum of the relative atomic masses of all the atoms in one molecule of the substance is referred to as ----------
A) Relative molecular mass B) Relative abundance C) Relative avogadro's abundance D) Relative atomic mass
- 20. 20. The electronic configuration of an atom is: 2, 8, 7. What element is it?
A) Sulphur B) Chlorine C) Argon D) Potassium
- 21. The shape of the p-orbitals is -------
A) Spherical B) Dumb-bell C) Longitudinal symmetrical D) Oval
- 22. --------------- states that electrons are distributed among orbitals of the same subshell singly before pairing occurs.
A) Pauli's principle B) Azimuthal rule C) Aufbau principle D) Hund's rule
- 23. The maximum number of electrons which can occupy the energy sub-level "f" is ......
A) 8 B) 10 C) 14 D) 6
- 24. When an atom gains an electron, it becomes ........
A) Negatively charged B) Chemically inactive C) Complex ion D) Cation
- 25. The shape of the S-orbitals is .......
A) Circular B) Spherically symmetrical C) Dumb-bell D) Longitudinally symmetrical
- 26. The principal quantum number "k" takes maximum of ....
A) 2 electrons B) 10 electrons C) 6 electrons D) 8 electrons
- 27. No two electrons in the same atom can have the same values for all four quantum numbers . This is the ..........
A) Aufbau principle B) Pauli exclusive principle C) Azimuthal D) Hund's rule
- 28. The maximum number of electrons which can occupy the "s" energy sub-level is .........
A) 8 electrons B) 6 electrons C) 2 electrons D) 32 electrons
- 29. One of the following is a diatomic element.
A) Nitrogen B) Phosphorus C) Sulphur D) Ozone
- 30. The smallest particle which can participate in chemical reactions is know as......
A) Molecule B) Compound C) Atom D) Matter
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