Engineering Chemistry Solved MCQs with Answers

1. What is the first step in Crystallization?

(A) Nucleation

(B) Evaporation

(C) Solidification

(D) Diffusion

2. Crystallization is mainly used to separate:

(A) Gas–Gas mixtures

(B) Immiscible liquids

(C) Solid from a solution

(D) Metals from alloys

3. Slow cooling in Crystallization produces:

(A) Smaller crystals

(B) No crystals

(C) Impure crystals only

(D) Larger crystals

4. The point where crystal growth begins is known as:

(A) Seed point

(B) Binding region

(C) Aggregation point

(D) Nucleation site

5. Which of the following is a highly branched polymer?

(A) Dendrimer

(B) Nylon

(C) PVC

(D) Cellulose

6. The central part of a Dendrimer is called its:

(A) Terminal group

(B) Core

(C) Shell

(D) Spacer

7. In Dendrimers, each branching layer is called a:

(A) Step

(B) Tier

(C) Generation

(D) Series

8. Crystallization occurs when a solution becomes:

(A) Dilute

(B) Saturated

(C) Acidic

(D) Super-saturated

9. Which type of Crystallization starts from a melted substance?

(A) Melt Crystallization

(B) Solution Crystallization

(C) Fractional Crystallization

(D) Cold Crystallization

10. Dendrimers are widely used in:

(A) Drug delivery

(B) Fuel storage

(C) Photography

(D) Welding

11. The outer surface of Dendrimers contains:

(A) Terminal functional groups

(B) Metals

(C) Inactive groups

(D) Vacancies

12. Crystallization is considered a method of:

(A) Chemical reaction

(B) Polymerization

(C) Purification

(D) Electrolysis

13. Dendrimers were first synthesized by:

(A) Flory

(B) Watson

(C) Berzelius

(D) Tomalia

14. Rapid cooling of a solution produces:

(A) Larger crystals

(B) Smaller crystals

(C) No crystals

(D) Only amorphous solids

15. In Crystallization, impurities generally:

(A) Improve crystal clarity

(B) Do not affect crystal formation

(C) Increase crystal size

(D) Inhibit crystal growth

16. A higher generation Dendrimer has:

(A) Fewer branches

(B) Less functionality

(C) No core

(D) More branches

17. Which property of Dendrimers allows encapsulation of drugs?

(A) Strong acidity

(B) Metallic bonding

(C) Linear structure

(D) Hollow interior

18. Crystallization efficiency increases when the rate of cooling is:

(A) Properly controlled

(B) Very fast

(C) Zero

(D) Irregular

19. PAMAM is a type of:

(A) Dendrimer

(B) Metal

(C) Carbohydrate

(D) Catalyst

20. Crystal purity increases when:

(A) Cooling is fast

(B) Solution contains more impurities

(C) Stirring is absent

(D) Cooling is slow

21. Crystallization involves:

(A) Random mixing

(B) Formation of gases

(C) Breaking down solids

(D) Orderly arrangement of molecules

22. Which form is opposite to crystalline form?

(A) Latticed

(B) Structured

(C) Transparent

(D) Amorphous

23. Dendrimers show which type of architecture?

(A) Linear

(B) Cyclic

(C) Branched

(D) Random coil

24. The process of adding a seed crystal is called:

(A) Triggering

(B) Seeding

(C) Spreading

(D) Diluting

25. Dendrimers differ from regular polymers because they have:

(A) No molecular weight

(B) Perfect branching

(C) No functional groups

(D) Natural origin

26. Crystallization is more efficient when the solvent is:

(A) Highly viscous

(B) Pure

(C) Reactive

(D) Colored

27. The final layer of Dendrimers is known as the:

(A) Core

(B) Generation zero

(C) Surface

(D) Shell

28. Crystal size is influenced MOST by:

(A) Color

(B) Cooling rate

(C) pH only

(D) Container shape

29. Dendrimers often have:

(A) Uniform size and shape

(B) Irregular shapes

(C) Random chain lengths

(D) Unpredictable branching

30. Which is a common application of Crystallization?

(A) Purifying solids

(B) Increasing viscosity

(C) Forming alloys

(D) Catalysis

31. Dendrimer drug delivery is effective because of their:

(A) Single branch

(B) High surface functionality

(C) Metallic nature

(D) Elasticity

32. In Crystallization, a solute becomes solid when:

(A) Temperature increases

(B) Pressure decreases

(C) Solution becomes super-saturated

(D) Light is applied

33. Dendrimer generations increase:

(A) Toxicity always

(B) Weight only

(C) Terminal groups

(D) Metallic behavior

34. A well-formed crystal has:

(A) Irregular boundaries

(B) Sharp edges

(C) No structure

(D) Hollow shape

35. Dendrimers are synthesized by:

(A) Divergent and convergent methods

(B) Evaporation

(C) Melting

(D) Filtration

36. Which factor does NOT affect crystallization?

(A) Magnetic field

(B) Solvent type

(C) Temperature

(D) Level of saturation

37. Dendrimers can carry drugs by:

(A) Encapsulation

(B) Absorption

(C) Evaporation

(D) Condensation

38. The purity of crystals is improved by:

(A) Re-crystallization

(B) Heating strongly

(C) Keeping impurities

(D) Rapid stirring

39. Dendrimers are best described as:

(A) Ring polymers

(B) Tree-like structures

(C) Linear chains

(D) Metals

40. Crystallization often requires:

(A) Under-saturation

(B) Oversaturation

(C) Dehydration

(D) Polymerization

41. The internal cavities of Dendrimers are useful for:

(A) Fuel combustion

(B) Metal welding

(C) Drug loading

(D) Crystallizing salts

42. Crystal defects occur mainly due to:

(A) Ideal conditions

(B) Chemical purity

(C) Rapid cooling

(D) High order

43. A Dendrimer’s repeated branching is called:

(A) Dendritic growth

(B) Amplification

(C) Layer collapsing

(D) Chain bending

44. Crystals are usually:

(A) Completely disordered

(B) Irreversible

(C) Highly ordered

(D) Weightless

45. Dendrimers can be used for gene delivery because they:

(A) Are acidic

(B) Melt easily

(C) Bind DNA

(D) Form metals

46. Crystallization depends mostly on:

(A) Solubility difference

(B) Light energy

(C) Magnetic field

(D) Gas pressure

47. The shell of a Dendrimer is mainly composed of:

(A) Core molecules

(B) Terminal groups

(C) Impurities

(D) Fillers

48. Impurities cause crystals to become:

(A) More uniform

(B) Less pure

(C) More stable

(D) Fully transparent

49. Which method increases crystal size?

(A) Shock cooling

(B) Slow cooling

(C) Ultraviolet exposure

(D) Mechanical grinding

50. Dendrimers are MOST known for their:

(A) High melting point

(B) Controlled architecture

(C) Absence of branches

(D) Toxicity