Bio-Chemistry Interview Question & Answers
Dear Readers, Welcome to Bio-Chemistry Interview Questions have been designed specially to get you acquainted with the nature of questions you may encounter during your Job interview for the subject of Bio-Chemistry. These Bio-Chemistry Questions are very important for campus placement test and job interviews. As per my experience good interviewers hardly plan to ask any particular questions during your Job interview and these model questions are asked in the online technical test and interview of many Medical companies.
1. Give the example for electrophilic substitution reaction?
The species, which accepts the electrons, are called Electrophilles (or) Electrophilic reagents.
When the atom (or) group of atoms present in the organic compound is replaced by another atom (or) group of atoms (electrophilic) is called electrophilic substitution reaction.
2. What is addition reaction?
When atoms (or) group of atoms are added, to form more saturated compound it is called addition reaction.
3. How do you define free radical addition reaction? Give an example.
When unsaturated compounds undergo addition reactions with free radicals,
it is called free radical addition reaction.
Ex; CH3-CH = CH2+HBr-----------> CH3-CH2-CH2Br
4. What is nucleophilic addition reaction?
When the attacking species during the addition reaction is Nucleophilic, it is nucleophilic addition reaction. Ex; Acetaldehyde cynohydrin
5. What is electrophilic addition reaction?
When the attacking species during the addition reaction is Electrophile, it is called electrophilic addition reaction. Ex; (+) (-) (+) (-) (+) (-)
CH2Br-CH2BràH2C-CH2+BrBr-àH2C=CH2+Br2-
6. What are the favorable conditions for formation of cat ions?
1. Low Ionisational potential
2. Lesser Charge
3. More atomic size of atoms forms cations easily
4. Ions having Inert gases configuration formed easily
7. What are the favorable conditions for formation of Anions?
• High Electron affinity
• Small size
Less charge of an atoms form anion more easily
8. Define lattice energy.
The energy released when one mole of ionic crystal is formed by the combination of the corresponding gaseous (+ve) and (-ve) ions brought from infinite distance is called lattice energy.
9. What happens if Lattice energy increases?
• The Strength of ionic bond
• Stability of the Ionic compound
• Ease of formation of the Ionic bond Increases
10. What is Sublimation energy?
The amount of energy required to convert one mole of solid substance to vapor state is called Sublimation energy.
11. What can you calculate by selecting Born-Haber cycle?
Born-Haber cycle is useful for calculation of lattice energy, heat of reaction and electron affinity.
12. How can energy change in the formation of NACL be determined?
With the help of Born Haber’s cycle
13. What is the relation between reaction taking place in one of the several stages and the total amount of energy liberated in the reaction?
The relation between reaction taking place in one of the several stages and the total amount of energy liberated in the reaction is same.
14. Define limiting radius.
The ratio between the radius of cation and the radius of anion is called Limiting radius.
15. What is Co-ordination number?
The number of appositively charged ions surrounded a particular ion in an ionic crystal lattice is called co- ordination number
16. What is structure of Nacl and give the co-ordination number of Nacl?
The structure of Nacl is face centered Cubic and Co- ordination number of Nacl is 6
17. What is the structure of cscl and give the co-ordination number of Cscl?
The structure of cscl is Body Centered Cubic and the Co- ordination number of CsCl is 8
18. Ionic compound does not show the property of space isomerism, Give the reason?
Ionic bond is Electrostatic. It is non directional, so Ionic compounds does not show the property of Space Isomerism
19. In double bond, how many sigma and Pi bonds are present in it?
Double bond = 1 Sigma bond and one Pi bond
Among sigma and Pi bonds which is the stronger one
Sigma bond is Stronger than pi bond
20. Define polar covalent bond.
The covalent bond formed by the unequal sharing of electrons between the two atoms is called polar covalent bond.
21. What is dipole?
In polar covalent molecule, one atom gets positive charge and the other one gets negative charge hence called dipole.
22. Covalent bond is directional therefore which covalent property is shown?
Space Isomerism
23. Which theory explains the paramagnetic nature of oxygen? Who proposed it?
Molecular orbital theory, proposed by Hunds and Mulliken
24. Define co-ordination covalent bond.
Co-ordination covalent bond is formed by the mutual sharing of pair of electrons between two atoms contributed by only one of the combining atoms.
25. What does one Debye equals?
10-18 e.s.u – Cm
26. If a polar molecule has a charge of 4.8 * 10^ (-10) and internuclear distance is 1A then what is its dipole moment?
4.8 * 10-10 e.s.u * 1A0
4.8 * 10-10 * 10-8
4.8 * 10-18 e.s.u – Cm
= 4.8 Debye
Give the mathematical expression to calculate or measure the percentage of ionic Character.
% of Ionic Character = (Observed dipole moment / Dipole moment of 100% ionic bond)*100
27. Who proposed VSEPR theory? What does it explain?
VSEPR theory was proposed by Sedgwick and Powell. It explains the shapes of polyatomic molecules.
28. In water molecule the bond angle decreases from 109.28 to 104.5, why this does happens?
The repulsion between lone pair and lone pair electrons
In NH3 molecule, the bond angle decreases from 109.28 to 107.3 why does it happen.
The more repulsion between lone pair and bond pair
29. Define Hybridization.
The distribution of electrons into Hybrid orbitals is as per the Paulis Exclusion principle and the Hunds rule of Maximum Multiplicity.
According to which rule the distribution of electrons into hybrid orbital takes place.
The distribution of electrons into Hybrid orbitals is as per the Paulis Exclusion principle and the Hunds rule of Maximum Multiplicity.
30. What is the shape of molecules SF6 and IF7?
SF6 is Octahedral
IF7 is pentagonal Bipyramidal
Give the reason why the water molecule has high Boiling point and melting points.
Due to the presence of Hydrogen bond in water molecule.
31. What are the units of bond length?
The intermolecular distance between the bonded atoms in a molecule is called bond length and the units are Angstrom units (A0)
32. What is the order of C-H bond length in C2H6 and C2H4 and C2H2?
c2h6>c2h4 >c2h2
33. Define bond angle.
The angle between the lines joining the nuclei of the bonded atom with a central atom is called bond angle.
34. Define bond energy.
The amount of energy released when one mole of bonds are formed between the corresponding gaseous atoms is called Bond energy.
35. Define the phenomenon resonance.
When a molecule is represented by two or more nearly equal structures, which differ in the arrangement of electrons, then the molecule is said to exhibit resonance.
36. Which group of elements is called alkaline earth metals?
1st A group because the oxides and hydrides are alkaline in nature
Among 1A group elements why the element lithium is the most powerful, reducing agent in equivalent state
Due to its low sublimation and hydration energy
37. What is the property of Alkaline earth metal Ions?
Lithium
38. Which metal is more metallic in nature among 1A group elements?
Francium
39. Which element in 1A group does not form peroxides?
Lithium
40. Which property among the following generally increases from top to bottom in a group 1A?
1. Electropositive, Density, Basic nature, classical reactivity
Electropositive, Density, Basic nature, classical reactivity, and solubility generally increase from top to bottom from lithium to caesium.
41. Which property among the following generally decreases from top to bottom in a group 1A?
1. Electropositive, Density, Basic nature, classical reactivity
Electro affinity, electro negativity, Ionisational potential, melting and boiling points decreases from top to bottom in a group 1A from lithium to caesium
42. Alkaline metals when dissolved in ammonium (NH3) act as better conductor and better reducing agent what is the reason behind it?
Due to formation of solvated or Ammoniated electrons
43. Which element in 1A group is lighter than water?
Lithium, Sodium, and potassium
44. What are the raw materials used for the precipitation of Na2Co3 by Solvay ammonium Process?
Sodium Chloride, limestone and ammonia
45. Give the chemical formula for Borax.
(Na2) B4 (O7) .10(H2) O
46. Give the formula for Peral Ash.
The formula for Peral Ash is K2CO3.
47. What are the compounds used for extraction of Gold and Silver?
NaCN and KCN
48. Which is the most Abundant Alkaline earth element?
Calcium
49. Which is the least abundant Alkaline earth element?
Radium
50. What is the Chemical formula for Epsom salt?
MgSO4. 7H20