- 1. 1. In which of the following separation methods does chemical reaction occur?
A) Chromatography
B) Sublimation
C) Distillation
D) Precipitation
- 2. 2. The purity of a solid sample can best be determined by its :
A) Boiling points
B) Conductivity
C) Solubility
D) Melting point
- 3. 3. The constituent of lead pigment can be separated by:
A) Fractional distillation
B) Chromatography
C) Filtration
D) Fractional crystallisation
- 4. 4. Which of the following properties is not employed in the separation of a mixture?
A) Molar masses
B) Solubility
C) Densities
D) Boiling points
- 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) Filtration
C) Boiling off the ethanol
D) Fractional distillation
- 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) Evaporation
B) Melting
C) Crystallisation
D) Sublimation
- 7. 7. Fractional distillation is used to separate:
A) Substances which differ in their solubilities in a solvent
B) Liquids with different boiling points
C) Gaseous, liquid or solid impurities from a mixture
D) An insoluble substance from a soluble substance
- 8. 8. A mixture of kerosene and water can be separated by:
A) Separating funnel
B) Sublimation
C) Crystallisation
D) Distillation
- 9. 9. What is the mass number of an element if its atom contains 10 protons, 10 electrons, and 12 neutrons?
A) 22
B) 20
C) 32
D) 10
- 10. 10. The electronic configuration of an atom is 2,8,8,2. The atomic number of the element is, therefore ----------:
A) 10
B) Z15
C) 18
D) 20
- 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) 42.66%
B) 28.07%
C) 21.33%
D) 14.71%
- 13. 13. How many electrons are in the ion F, If 19 F has neutron of 8?
A) 9
B) 8
C) 27
D) 11
- 14. 14. Calculate the formula mass of tri lead tetraoxide Pb3O4 (Pb= 207, O = 16)
A) 865
B) 621
C) 586
D) 685
- 15. 15. Calculate the formula mass of tetraoxosulphate (VI) acid H2SO4 (S= 32, H = 1, O = 16)
A) 98
B) 102
C) 40
D) 64
- 16. 16. What is the molecular mass of calcium trioxonitrate (V) Ca (NO3)_2 (Ca = 40, N = 14, O = 16)
A) 160
B) 104
C) 146
D) 164
- 17. 17. One of the following is the Avogadro's constant:
A) 6.02 × 10-23
B) 6.02 × 10-32
C) 6.02 × 1023
D) 6.02 × 1032
- 18. 18. The relative atomic mass of any element in grams contains -------- mole of atom
A) 1
B) 4
C) 3
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 abundance
B) Relative molecular mass
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) Chlorine
B) Argon
C) Potassium
D) Sulphur
- 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) Azimuthal rule
B) Hund's rule
C) Pauli's principle
D) Aufbau principle
- 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) Complex ion
B) Chemically inactive
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) 8 electrons
B) 10 electrons
C) 6 electrons
D) 2 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) Hund's rule
C) Azimuthal
D) Pauli exclusive principle
- 28. The maximum number of electrons which can occupy the "s" energy sub-level is .........
A) 32 electrons
B) 6 electrons
C) 2 electrons
D) 8 electrons
- 29. One of the following is a diatomic element.
A) Phosphorus
B) Ozone
C) Sulphur
D) Nitrogen
- 30. The smallest particle which can participate in chemical reactions is know as......
A) Compound
B) Atom
C) Matter
D) Molecule
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