Chemistry Questions

Q:

What is the bond order of O2?

A) 1.5 B) 2
C) 2.5 D) 1
 
Answer & Explanation Answer: B) 2

Explanation:

The number of bonds between a pair of atoms is called the bond order.

Bond orders can be calculated from Lewis structures, which are the heart of the valence-bond model. Oxygen, for example, has a bond order of two.

Structure

When there is more than one Lewis structure for a molecule, the bond order is an average of these structures. The bond order in sulfur dioxide, for example, is 1.5  the average of an S-O single bond in one Lewis structure and an S=O double bond in the other.

Structures

In molecular orbital theory, we calculate bond orders by assuming that two electrons in a bonding molecular orbital contribute one net bond and that two electrons in an antibonding molecular orbital cancel the effect of one bond. We can calculate the bond order in the O2 molecule by noting that there are eight valence electrons in bonding molecular orbitals and four valence electrons in antibonding molecular orbitals in the electron configuration of this molecule. Thus, the bond order is two.

Equation

Report Error

View Answer Report Error Discuss

Filed Under: Chemistry
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Analyst , Bank Clerk , Bank PO

1 2915
Q:

What type of compound is Lecithin?

A) Sterol B) Phospholipid
C) Lipoprotein D) Glycolipid
 
Answer & Explanation Answer: B) Phospholipid

Explanation:

Lecithin is a Phospholipid type of compounds. The main phospholipids in lecithin from soya and sunflower are phosphatidyl choline, phosphatidyl inositol, phosphatidyl ethanolamine, and phosphatidic acid.

Report Error

View Answer Report Error Discuss

Filed Under: Chemistry
Exam Prep: AIEEE , Bank Exams
Job Role: Analyst , Bank PO

4 2889
Q:

In a compound, chemical energy is contained in the

A) bonds B) movement of the electrons
C) unbonded electrons D) nuclei of the atoms
 
Answer & Explanation Answer: A) bonds

Explanation:

chemical energy is contained in the chemical bonds between the reactants in the chemical compounds.

Report Error

View Answer Report Error Discuss

Filed Under: Chemistry
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Analyst , Bank Clerk , Bank PO

0 2885
Q:

Energy produced in nuclear reaction is given by

A) Charle's law B) Grahm's law
C) Gay - Lussac's law D) Einstein's law
 
Answer & Explanation Answer: D) Einstein's law

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Chemistry

2 2881
Q:

Which of the following is not a pure substance?

A) Oxygen B) Carbon dioxide
C) Water D) Milk
 
Answer & Explanation Answer: D) Milk

Explanation:

Milk is not a pure substance since it has so many constituents that can be separated physically.

Compounds are pure substances formed from elements unlike mixtures.

Report Error

View Answer Report Error Discuss

Filed Under: Chemistry
Exam Prep: AIEEE , Bank Exams , CAT , GATE
Job Role: Analyst , Bank Clerk , Bank PO

2 2869
Q:

Tertiary structure is NOT directly dependent on

A) hydrogen bonds B) ionic bonds
C) peptide bonds D) hydrophobic interactions
 
Answer & Explanation Answer: C) peptide bonds

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Chemistry
Exam Prep: AIEEE , Bank Exams , CAT
Job Role: Analyst , Bank Clerk , Bank PO

0 2850
Q:

What types of orbital overlap occur in Cumulene?

Answer

A cumulene is a hydrocarbon with three or more cumulative double bonds. They are analogous to allenes, only having a more extensive chain. The simplest molecule in this class is butatriene, which is also called simply cumulene.


 


The carbons on the ends are sp² hybridized, with a p-orbital for the 'second' bond in the double bond with their neighboring carbons.


They have those sp² orbitals overlapping with the s from the hydrogen, and they have a p overlapping in the pi bond with the neighboring carbon. They also have a sigma bond with the neighboring carbon I'll get to.


The middle carbons each have two pi bonds with their neighbors, leaving sp hybridiaztion for the rest. So they have sp/sp² with the end carbons, and sp/sp with each other. (And they also have p/p in the pi bonds).


 


All orbital overlappings in Cumuene are :


* s/sp²


* p/p


* sp/sp²


* sp/sp

Report Error

View answer Workspace Report Error Discuss

Subject: Chemistry Exam Prep: AIEEE , Bank Exams , CAT
Job Role: Analyst , Bank Clerk , Bank PO

1 2850
Q:

Browning of paper in old books is caused by

A) oxidation of cellulose B) collection of dust
C) frequent use D) lack of aeration
 
Answer & Explanation Answer: A) oxidation of cellulose

Explanation:
Report Error

View Answer Report Error Discuss

Filed Under: Chemistry
Exam Prep: AIEEE , Bank Exams , CAT
Job Role: Analyst , Bank Clerk , Bank PO

1 2841