In chemical science, polymorphism refers to the occurrence of a solid substance in two or more crystalline forms. It is a type of isomerism shown by any crystalline substance. It plays a vital role in the pharma industry for drug development. The crystal structure helps in determining the drug’s usefulness.
|
Definition: Polymorphism refers to the ability of the chemical composition to crystallise in two or more forms. It occurs due to temperature or pressure change. |
Polymorphism Chemistry Questions with Solutions
Q1. Which of the following exhibit the largest London force?
(a) Small molecules
(b) Large molecules
(c ) Neutral molecules
(d) None of the above
Answer: (b) Large molecules exhibit the largest London force.
Q2. Meta stable compounds exhibit
(a) Long survival
(b) Large wavelength
(c ) Both (a) and (b)
(d) None of the above
Answer: (a) Meta stable compounds exhibit long survival.
Q3. Which of the following has a single isotope?
(a) Gold
(b) Calcium
(c ) Cadmium
(d) None of the above
Answer: (a) Gold has a single isotope.
Q4. A compound exist in _______ form in polymorphism.
(a) One
(b) Two
(c ) More than one
(d) None of the above
Answer: (c ) A compound exists in more than one form in polymorphism.
Q5. Bone black is a polymorph of
(a) Sulphur
(b) Phosphorous
(c ) Carbon
(d) None of the above
Answer: (b) Bone black is a polymorph of phosphorous.
Q6. What is polymorphism?
Answer: Polymorphism refers to the ability of the chemical composition to crystallise in two or more forms. It occurs due to temperature or pressure change.
Q7. What is the primary difference between polymorphism and allotropy?
Answer: The primary difference between polymorphism and allotropy is that polymorphism refers to the ability of the chemical composition to crystallise in two or more forms. In contrast, allotropy refers to the ability of the element to exist in two or more molecular structures.
Q8. What is polymorph? Give an example.
Answer: The different crystalline structures of a compound is referred to as polymorph. Zinc blende and wurtzite are the two polymorphs of zinc sulphide.
Q9. What is the primary difference between polymorphism and isomerism?
Answer: The primary difference between polymorphism and isomerism is that polymorphism refers to the ability of the chemical composition to crystallise in two or more forms. In contrast, isomerism refers to the ability of a compound to exist in two or more different atomic structures.
Q10. What do you understand by the term isomorphism?
Answer: Isomorphism refers to the existence of the same crystalline structures of two different compounds. The crystal shape of an isomorphic compound is identical to each other.
Q11. Do organic compounds show polymorphism?
Answer: Yes, organic compounds show polymorphism. It is the result of conformational polymorphism.
Q12. What are polymorphisms and their types?
Answer: Polymorphism refers to the ability of the chemical composition to crystallise in two or more forms. There are two types of polymorphism.
1. Monotropic Polymorphism
2. Enantiotropic Polymorphism
Q13. Name a technique which is used to identify polymorphism.
Answer: Gel electrophoresis is used to identify polymorphism.
Q14. What is the significance of polymorphism?
Answer: Polymorphism refers to the ability of the chemical composition to crystallise in two or more forms. It plays a crucial role in the pharma industry for drug development. The crystal structure helps in determining the drug’s usefulness.
Q15. How will you differentiate between isomorphism and polymorphism?
Answer: We can differentiate between isomorphism and polymorphism in the following ways.
|
S. No. |
Isomorphism |
Polymorphism |
|---|---|---|
|
1. |
Isomorphism refers to the resemblance in the crystalline structures of two different compounds. |
Polymorphism refers to the existence of distinct crystalline forms of the same compound. |
|
2. |
Isomorphic compounds have identical crystal shapes. |
Polymorphic compounds have different crystal structures. |
|
3. |
Isomorphism involves more than one compound at a time. |
Polymorphism involves one compound at a time. |
|
4. |
It is not seen in elements. |
It may be observed in elements. |
|
5. |
Isomorphous compounds have an identical atomic ratio. |
Polymorphic compounds may or may not have identical atomic ratios. |
Practise Questions on Polymorphism
Q1. What is the significance of polymorphism in pharma industries?
Q2. How does polymorphism affect the characteristics of drugs?
Q3. What do you understand by the term monotropic polymorphism?
Q4. What do you understand by the term Enantiotropic Polymorphism?
Q5. What is the effect of polymorphism on a compound?
Click the PDF to check the answers for Practice Questions.
Download PDF
