- 1. 1. In which of the following separation methods does chemical reaction occur?
A) Sublimation
B) Distillation
C) Chromatography
D) Precipitation
- 2. 2. The purity of a solid sample can best be determined by its :
A) Melting point
B) Boiling points
C) Solubility
D) Conductivity
- 3. 3. The constituent of lead pigment can be separated by:
A) Chromatography
B) Fractional crystallisation
C) Filtration
D) Fractional distillation
- 4. 4. Which of the following properties is not employed in the separation of a mixture?
A) Densities
B) Solubility
C) Boiling points
D) Molar masses
- 5. 5. Ethanol is a product of fermentation of simple sugars. Which method is used to separate ethanol from the other products?
A) Fractional crystallisation
B) Fractional distillation
C) Boiling off the ethanol
D) Filtration
- 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) Sublimation
C) Evaporation
D) Crystallisation
- 7. 7. Fractional distillation is used to separate:
A) Gaseous, liquid or solid impurities from a mixture
B) Substances which differ in their solubilities in a solvent
C) An insoluble substance from a soluble substance
D) Liquids with different boiling points
- 8. 8. A mixture of kerosene and water can be separated by:
A) Sublimation
B) Crystallisation
C) Distillation
D) Separating funnel
- 9. 9. What is the mass number of an element if its atom contains 10 protons, 10 electrons, and 12 neutrons?
A) 32
B) 20
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) Z15
B) 10
C) 20
D) 18
- 11. 11. What is the percentage by mass of sodium in sodium hydroxide? (Na = 23, O = 16, H = 1)
A) 40.4%
B) 42.5%
C) 57.5%
D) 73.0%
- 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) 9
B) 27
C) 8
D) 11
- 14. 14. Calculate the formula mass of tri lead tetraoxide Pb3O4 (Pb= 207, O = 16)
A) 586
B) 621
C) 685
D) 865
- 15. 15. Calculate the formula mass of tetraoxosulphate (VI) acid H2SO4 (S= 32, H = 1, O = 16)
A) 40
B) 64
C) 98
D) 102
- 16. 16. What is the molecular mass of calcium trioxonitrate (V) Ca (NO3)_2 (Ca = 40, N = 14, O = 16)
A) 146
B) 104
C) 164
D) 160
- 17. 17. One of the following is the Avogadro's constant:
A) 6.02 × 1032
B) 6.02 × 10-23
C) 6.02 × 10-32
D) 6.02 × 1023
- 18. 18. The relative atomic mass of any element in grams contains -------- mole of atom
A) 4
B) 3
C) 1
D) 2
- 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 atomic mass
C) Relative avogadro's abundance
D) Relative abundance
- 20. 20. The electronic configuration of an atom is: 2, 8, 7. What element is it?
A) Sulphur
B) Argon
C) Chlorine
D) Potassium
- 21. The shape of the p-orbitals is -------
A) Spherical
B) Dumb-bell
C) Oval
D) Longitudinal symmetrical
- 22. --------------- states that electrons are distributed among orbitals of the same subshell singly before pairing occurs.
A) Aufbau principle
B) Pauli's principle
C) Hund's rule
D) Azimuthal rule
- 23. The maximum number of electrons which can occupy the energy sub-level "f" is ......
A) 8
B) 14
C) 6
D) 10
- 24. When an atom gains an electron, it becomes ........
A) Chemically inactive
B) Complex ion
C) Cation
D) Negatively charged
- 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) 6 electrons
C) 10 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) Pauli exclusive principle
B) Aufbau principle
C) Azimuthal
D) Hund's rule
- 28. The maximum number of electrons which can occupy the "s" energy sub-level is .........
A) 2 electrons
B) 6 electrons
C) 8 electrons
D) 32 electrons
- 29. One of the following is a diatomic element.
A) Ozone
B) Phosphorus
C) Sulphur
D) Nitrogen
- 30. The smallest particle which can participate in chemical reactions is know as......
A) Matter
B) Atom
C) Compound
D) Molecule
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