Chemistry

Chemical Bonding and Molecular Structure

1,420 Questions

This section tests your knowledge of chemical bonding, molecular structure, and hybridization. It covers ionic and covalent bonds, octet rule exceptions, and molecular geometry. These chemistry questions are common in various competitive entrance examinations.

Ionic and covalent bondsHybridisation of elementsOctet rule exceptionsMolecular geometryIntermolecular forces

Chemical Bonding and Molecular Structure Questions

Multiple choice chemistry hydroxy compounds and ethers physical properties of ethers ethers alcohols, phenols and ethers

 Least boiling point is of:

  1. ethylene glycol

  2. ether

  3. water

  4. phenol
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ether has least boiling point as it cannot form hydrogen bonds. Ethylene glycol, water and phenol can form intermolecular hydrogen bonds which lead to intermolecular hydrogen bonding and high boiling points. Hydrogen bonding is possible when $H$ atom is attached to electronegative $N,\ O$ or $F$ atom.

Multiple choice chemistry hydroxy compounds and ethers physical properties of ethers ethers alcohols, phenols and ethers

Ethers show dipolar nature due to the presence of ______.

  1. central C atom

  2. central O atom

  3. central N atom

  4. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ethers have general structural formula R-O-R'. Hence all of them have the C-O bond. We know that the C-O bond is polar due to the difference between the electronegativities of carbon and oxygen. Hence, ethers show dipolar nature.

Multiple choice chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

Hydrogen exists in atomic state in which of the following compounds?

  1. Metallic hydrides

  2. Ionic Hydride

  3. Molecular hydrides
  4. ${ H } _{ 2 }O$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Metal hydrides are metals which have been bonded to hydrogen to form a new compound. Any hydrogen compound that is bonded to another metal element can effectively be called a metal hydride. Generally, the bond is covalent in nature, but some hydrides are formed from ionic bonds.
  • Hence option A is a correct answer.
Multiple choice chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

Among I-A elements which can form ionic as well as covalent bonds? 

  1. Hydrogen

  2. Cerium

  3. Helium

  4. Sodium
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Hydrogen is the lightest element on the periodic table. Hydrogen forms covalent compounds with non metals. In ionic compounds hydrogen can take the form of negative charge when it is known as hydride or a cation.

Multiple choice chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

Hydrogen differs from elements of $I-A$ group as:

  1. it can form ionic as well as covalent bond

  2. all are metals
  3. $ H^+$ is unstable in water
  4. both $A$ and $B$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The options A and B are the correct answers.
Hydrogen differs from elements of $I-A$ group as:
(A) hydrogen can form ionic as well as covalent bond whereas elements of $I-A$ group can form only ionic bonds.
(B) All elements of $I-A$ group are metals. Hydrogen (with very high ionization energy does not possess metallic character).
(C) $H^+$ ion is stable in water.

Multiple choice chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

Which of the one is correct about Hydrogen?

  1. resembles in IA since it forms monovalent cation $H^+$.
  2. resembles in VIIA (halogen family) since it forms monovalent anion $H^-$.

  3. resembles in IVA(carbon family) since both have a half filled shell of electron

  4. all of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In HCl, H has + 1 oxidation state so it resembles IA group property.


In NaH, H has -1 oxidation state so it resembles VIIA group property. 

H due to half-filled s shell of electron it resembles IVA group property.

So option D is the correct answer. 

Multiple choice chemistry the p-block elements - group 13 study of orthoboric acid some important compounds of boron study of boron

$2B+3H _{2}SO _{4}\rightarrow 2H _{3}BO _{3} +A$ 


The hybridization of central atom in compound A is :

  1. sp
  2. $sp^{2}$
  3. $sp^{3}$
  4. $sp^{3}d$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The balanced chemical reaction is as given below.
$2B+3H _{2}SO _{4}\rightarrow 2H _{3}BO _{3}\rightarrow + \underset {A} {SO _2}$
S atom in sulphur dioxide undergoes $sp^2$ hybridization.

Multiple choice chemistry the p-block elements - group 13 study of orthoboric acid some important compounds of boron study of boron

The states of hybridisation of boron and oxygen atoms in boric acid $(\mathrm{H} _{3}\mathrm{B}\mathrm{O} _{3})$ are respectively:

  1. $\mathrm{s}\mathrm{p}$ and $\mathrm{s}\mathrm{p}^{2}$
  2. $\mathrm{s}\mathrm{p}^{2}$ and $\mathrm{s}\mathrm{p}^{3}$
  3. sp3 and $\mathrm{s}\mathrm{p}^{2}$

  4. sp3 and sp3
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The states of hybridisation of boron and oxygen atoms in boric acid $(\mathrm{H} _{3}\mathrm{B}\mathrm{O} _{3})$ are respectively are $\mathrm{s}\mathrm{p}^{2}$ and $\mathrm{s}\mathrm{p}^{3}$
respectively.

In boric acid the boron is surrounded by three bond pair thus it shows $sp^2$ hybridization while oxygen is surrounded by one two bond pair and two lone pairs so it shows $sp^3$ hybridization.

Multiple choice chemistry basic analytical techniques filtration and crystallisation other methods of separation separation techniques

Which of the following will not show the property of sublimation?

  1. Ammonium chloride

  2. Common salt

  3. Camphor

  4. Anthracene
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Sublimation is the transition of a substance directly from the solid to the gas phase without passing through the intermediate liquid phase. Ammonium chloride, camphor, anthracene can sublime but common salt cannot sublime.

Multiple choice chemistry basic analytical techniques filtration and crystallisation other methods of separation separation techniques

Which of the following can undergo sublimation?

  1. Iodine crystals

  2. Camphor

  3. Naphthalene balls

  4. All of above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

There are many substances which are converted into gas from solid when heated, and converted from gas to solid when cooled without converting into liquid. Such substances are known as sublime. For example, ammonium chloride, naphthalene balls, camphor, etc.

Multiple choice chemistry production of metals extraction of aluminium metallurgy of aluminium extraction of metals by electrolysis

During electrolysis of aluminium, which of the following substance is used as an electrolyte?

  1. $Al _2O _3$
  2. $Al _2O _3, Na _3AlF _6$
  3. $Al _2O _3, Na _3AlF _6, CaF _2$

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The substance which is used as an electrolyte during electrolysis of aluminium is $Al _2O _3, Na _3AlF _6, CaF _2$.

Multiple choice chemistry p- block elements-ii hydrogen chloride chlorine - 17 group p-block elements

Which of the follwoing statements is correct?

  1. HCl is covalent both in aqueous solution and in the gaseous state

  2. HCl is covalent in the gaseous state but ionic in aqueous solution

  3. HCl is ionic both in the gaseous state and in aqueous solution

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

HCl is covalent in the gaseous state but dissociates into ions in aqueous solution. It behaves like acid when aqueous.

Multiple choice chemistry p- block elements-ii hydrogen chloride chlorine - 17 group p-block elements

Name the ion(s) obtained when $HCl$ dissociates in aqueous solution.

  1. ${ H } _{ 3 }{ O }^{ + }$
  2. ${ Cl }^{ - }$
  3. Both $A$ and $B$

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Acidic nature of $HCl$ is due to hydrogen ions which reacts with water to form hydronium ions. 
$HCl(g) +{ H } _{ 2 }O \rightleftharpoons { H } _{ 3 }{ O }^{ + }+{ Cl }^{ - }$