8/6/2019 chem, chap-1 & 2

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CH#1&2

AL-REHMAN TALENTName------------------------------ Test: Chemistry (I)

Encircle the most suitable answer:1- Measurable size of objects under ordinary microscope is_____ nm(a) 100 (b) 200 (c) 300 (d) 502- Negatively charged particles are called

(a) Neutron (b) Radical (c) Anions (d) Cations

3- Phenomenon of isotopy is first discovered by(a) Dalton (b) Bohr (c) Soddy (d) Rutherford

4- Isotopes of an element have different number of

(a) Protons (b) Electrons (c) Neutron (d) Positrons

5- Oxygen has ________ isotopes(a) 2 (b) 3 (c) 4 (d) 5

6- There are _________ naturally occurring radioactive isotopes

(a) 15 (b) 30 (c) 40 (d) 507- During chemical reaction, particles involved are

(a) Protons (b) Electrons (c) Neutron (d) Positrons

8- One mole of O2 at S.T.P contains volume __________ liters(a) 32 (b) 16 (c) 22.4 (d) 18

9- Volume occupied by 0.1 mole of N2 at S.T.P is_____ liters

(a) 28 (b) 14 (c) 2.24 (d) 22.4

10- Drying of crystal through filter paper may cause ______ of crystals.(a) Decomposition (b) Breakdown (c) Adulteration (d) None

11- A complete characterization of a compound include ________ analysis

(a) Quantitative (b) Qualitative (c) Both a & b (d) None of them

12- Mercury is 13.6 time denser than water, this statement is(a) Quantitative (b) Qualitative (c) Both a & b (d) None of them

13- The solid remained at filter paper during the process of filtration is called(a) Filtrate (b) Residue (c) Media (d) Mother liquor

14- In chromatography technique, mobile phase may be

(a) Liquid (b) Gas (c) Both a & b (d) Solid15- In partition chromatography, stationary phase is

(a) Solid (b) Liquid (c) Gas (d) Both a & b

16- Slow cooling give rise to _________ sized crystals

(a) Small (b) Medium (c) Large (d) None17- Liquid remained after filtration, in the process of crystallization is called

(a) Filtrate (b) Residue (c) Media (d) Mother liquor 18- Objective of Crystallization is ___________ of compounds(a) Separation (b) Analysis (c) Purification (d) Identification

19- ________ is based on distribution la

(a) Chromatography (b) Solvent extraction (c) Both a & b (d) Crystallization

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8/6/2019 chem, chap-1 & 2

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CH#1&2

Short Questions:1. What is the purpose of followings?

(a) Filtration (b) Crystallization2. What is the effect of cooling on crystal size?

3. Enlist the steps involved in the process of crystallization?

4. Differentiate between partition and adsorption chromatography?5. What is distribution law? Briefly discuss with suitable example?

6. How can we decolorize the crystals, if any undesirable is appeared on crystals

during the process of crystallization?7. Why cationic radius is less than its parent atomic radius?

8. Differentiate b/w relative atomic mass and a.m.u?

9. Differentiate b/w empirical formula and molecular formula?

10. Differentiate b/w limiting reactant and excess reactant?11. Why theoretical yield is always greater than actual yield?

12. Why we use limiting reactant?

13. How isotopes are different from each other?

14. Calculate the number of the molecules in 50 grams of H2O?15. A compound has empirical formula as CH and its molecular mass is 78, what

will be its molecular formula and name?

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