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 ionic equilibrium introduction to ionic equilibria in solution ionic equilibrium in solution ionisation of weak acids and weak bases

Which of the following is/are ionization and not dissociation?

  1. $HCl \rightarrow H^+ + Cl^-$
  2. $Mg^+ \rightarrow Mg^{2+} + e^- $
  3. $Br _2 \rightarrow 2Br^.$
  4. $HBr \rightarrow H^+ + Br^-$
Reveal answer Fill a bubble to check yourself
A,D Correct answer
Explanation

In dissociation separation of ions take place which are already present as ions in the solid state. For example in the crystal structure of $NaCl$, $NaCl$ is present as $Na$ and $Cl$.

 In ionization, splitting of a neutral molecule into ions which are charged happen.
$HCl$ and $HBr$ are neutral $\mu $, there is no charge separation. But in solution they get ionised.

Multiple choice chemistry ionic equilibrium introduction to ionic equilibria in solution ionic equilibrium in solution ionisation of weak acids and weak bases

Generally speaking, how can you determine the charge of an ion formed by a representative element?

  1. The charge of the ion formed is related to the element's group number.

  2. The charge of the ion is related to the element's period number.

  3. An ion's charge is always 1/2 the atomic number.

  4. The charge of the ion is the number of valence electrons minus the number of core electrons.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Representative elements : s-block and p-block elements are representative elements.
The charge of the ion formed is related to the element's group number.
For example:
As Group-1 elements have +1 charge.
As Group-2 elements have +2 charge.

Multiple choice chemistry materials we use soap and detergents soap soap and detergent

Which of the following pairs of ions makes the water hard?

  1. $Na^+$
  2. $Cs^+$
  3. $Rb^+$
  4. $Ba^{+2}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Ion-exchange resin can soften both temporary and permanent hard water. The ion-exchange resin starts with sodium ions struck to it. As the bond water passes through the column, sodium ions come off the resin and go into the water.

Thus, ${ Na }^{ + }$ ions makes the water hard.

Multiple choice chemistry group 17 group 17 - physical properties physical properties of group 17 elements group 17 elements: the halogen family

The electron affinity values (in kJ $mol^{-1}$) of three halogens X, Y and Z are respectively$ -349, -333 $and $-325$.


 X, Y, and Z respectively are :

  1. $F _2, Cl _2, Br2$
  2. $Cl _2, F _2$ and $Br _2$
  3. $Cl _2, Br _2, F _2$
  4. $Br _2, Cl _2$ and $F _2$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

According to the values electron affinity the  three halogens X, Y and Z are $Cl _2$,$F _2$ and $Br _2$

Hence option B is correct

Multiple choice chemistry group 17 group 17 - physical properties physical properties of group 17 elements group 17 elements: the halogen family

Which of the following possesses the highest bond energy?

  1. $F _2$
  2. $Cl _2$
  3. $Br _2$
  4. $I _2$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$F _2$ is a smaller molecule than $Cl _2$. This means that the bonded electrons in $F _2$ are closer to the outer shell unbonded electrons. Due to the electron repulsion theory, the bonded electrons repel the outer shell unbonded electrons far more in $F _2$ than they would in $Cl _2$. 


since  $Cl _2$ has more shells so more shielding of the outer electrons. The fact that the bonded electrons in $F _2$ repel the unbonded electrons so much makes the molecule weak, so it is easier to break. 


Hence option B is correect.

Multiple choice chemistry group 17 group 17 - physical properties physical properties of group 17 elements group 17 elements: the halogen family

Which of the following does not truly represent the property indicated against it?

  1. $ Br _2 < Cl _2 < F _2 $ : Oxidising power
  2. $ Br < Cl < F $ : Electronegativity
  3. $ Br < F < Cl $ : Electron affinity
  4. $ Br _2 < Cl _2 < F _2 $ : Bond energy
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The correct arrangements along with properties are written against them.

$ Br _2 < Cl _2 < F _2 $ : Oxidising power

$ Br < Cl < F $ : Electronegativity

$ Br < F < Cl $ : Electron affinity

$ F _2 < Br _2 < Cl _2 $ : Bond energy

Thus,we see that the order of bond energy is incorrect in the question. The correct order is given above. 

Hence, option D is correct.
Multiple choice chemistry group 17 group 17 - physical properties physical properties of group 17 elements group 17 elements: the halogen family

Least melting point is shown by the compound-

  1. $PbCl _2$
  2. $SnCl _4$
  3. $NaCl$
  4. $AlCl _3$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

We know that greater the molecular size is; greater will be van der Waal force of attraction between then and higher will be its melting point.

Among given species since in $AlCl _3$; Al has the least size so the van der Waal force of attraction will be least and the melting point of it is lowest. But because of a molecular crystalline structure of $SnCl _4$, it has least melting point among given species.

Multiple choice chemistry group 17 group 17 - physical properties physical properties of group 17 elements group 17 elements: the halogen family

The bond energies of $F _{2}, Cl _{2}, Br _{2}$, and $I _{2}$ are 155 kJ $mol^{-1}, \ $244 kJ $mol^{-1}$, 193 kJ $mol^{-1}$ and 151 kJ $mol^{-1}$ respectively. The weakest bond will be in:

  1. $Br _{2}$
  2. $Cl _{2}$
  3. $F _{2}$
  4. $I _{2}$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Since the bond energy of $I _2$ is least, it's bond will be weakest.

Multiple choice chemistry group 17 group 17 - physical properties physical properties of group 17 elements group 17 elements: the halogen family

The compound IF$ 7$ is named as ________.

  1. iodine heptafluorine

  2. iodine septafluoride

  3. iodine fluoride

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

$IF _7$ is named as Iodine (VII) Flouride. Because the halogen of larger size give electron pair and the halogen of small size which has high electronegativity accepts a lone pair of electrons. So suffix '-ide' is added to halogen of small size.

Multiple choice chemistry mix and separate different types of solutions various mixtures introduction to solutions

Dissolution of ionic solid in water is possible when:

  1. $H$ lattice $> H$ hydration
  2. $H$ lattice $= H$ hydration
  3. $H$ hydration $: H$ lattice = 2:1
  4. $H$ hydration $> H$ lattice
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Solution:- (D) ${H} _{\text{hydration}} > {H} _{\text{lattice}}$

In order to dissolve an ionic solid, water molecules must break up the interactions between all of the ions in the solid. The heat of hydration $\left( {H} _{\text{hydration}} \right)$ offsets the lattice energy $\left( {H} _{\text{lattice}} \right)$ of an ionic solid to allow for solution formation to occur typically when ${H} _{\text{hydration}} > {H} _{\text{lattice}}$.