Tag: basics of chemical bonding

Questions Related to basics of chemical bonding

Effective charge on each oxygen is $-\frac{1}{4}$ in?

chemistry chemical bonding and structure formal charge basics of chemical bonding types of bonds

  1. $SO _{3}^{2-}$

  2. $SO _{3-}^{4}$

  3. $ClO _{3}^{-}$

  4. $ClO _{4}^{-}$

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Correct Option: C

Among ${ KO } _{ 2 },{ AIO } _{ 2 }^{ - },{ BaO } _{ 2 }\ and\ { NO } _{ 2 }^{ + }$, unpaired electron is present in :

chemistry chemical bonding and structure formal charge basics of chemical bonding types of bonds

  1. ${ NO } _{ 2 }^{ + }\quad and\quad { BaO } _{ 2 }$

  2. ${ KO } _{ 2 }\quad and\quad AI{ O } _{ 2 }^{ - }$

  3. ${ KO } _{ 2 }$ only

  4. $Ba{ O } _{ 2 }$ only

Show answer
Correct Option: C
Explanation:

This can be done by counting number of valence electrons


$KO _2=1+2\times 6=17$-Odd number of electrons and hence unpaired.


$AlO^{2-} _2=3+2\times 6+1=14$-Even number of electrons and hence paired.

$BaO _2=2+2\times6=14$-Even number of electrons and hence paired.

$NO^{+} _{2}=5+2\times6 -1=16$-Even number of electrons and hence paired.

Hence option C is the correct answer.

Which has highest specific charge?

chemistry chemical bonding and structure formal charge basics of chemical bonding types of bonds

  1. $Na^{+}(mass\ no\ =23)$

  2. $Mg^{2+}(mass\ no\ =24)$

  3. $Al^{+3}(mass\ no\ =27)$

  4. $Si^{+4}(mass\ no\ =28)$

Show answer
Correct Option: D
Explanation:

Specific charge in the ratio of charge of ion to its mass.

Specific charge $=\dfrac { e }{ M } $
For ${ Na }^{ + }=\dfrac { e }{ 23 } ,\quad $ for ${ Mg }^{ 2+ }=\dfrac { 2\times e }{ 24 } $
For ${ Al }^{ 3+ }=\dfrac { 3\times e }{ 27 } ,\quad $ for ${ Si }^{ 4+ }=\dfrac { 4\times e }{ 28 } $
In is in the following order,
${ Si }^{ 4+ }>{ Al }^{ 3+ }>{ Mg }^{ 2+ }>{ Na }^{ + }$

In bisulphate ion, the formal charge on sulphur atom is:

chemistry chemical bonding and structure formal charge basics of chemical bonding types of bonds

  1. $+1$

  2. $+2$

  3. $+4$

  4. $+6$

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Correct Option: B

Formal charge on nitrogen and oxygen in $NO^- _3$ ion are respectively: 

chemistry chemical bonding and structure formal charge basics of chemical bonding types of bonds

  1. $0, \dfrac{-1}{3}$

  2. $+1, \dfrac{-1}{3}$

  3. $+1, \dfrac{-2}{3}$

  4. $0, \dfrac{-2}{3}$

Show answer
Correct Option: A
Explanation:

Formula change is basically a change given to an atom, on assuming that the electrons in a chemical bond are shared equally between the atoms, neglecting theirrelative, $EN.$

$FC=V-N-\cfrac{B}{2}$       $(V=\text{no. of valance electron}\N=\text{No. of non bonding electrons}\B=\text{No. of electrons in covalent bond})$
$FC$ on $N$ in $NO^- _3=0$
$FC$ on $O$ in $NO _3^-=\cfrac{-1}{3}$

Which of the following given below is incorrect :

chemistry chemical bonding and structure formal charge basics of chemical bonding types of bonds

  1. ONF is isoelectronic with ${O _2}{N^ - }$

  2. ${\rm{O}}{{\rm{F}} _2}$ is an oxide of fluorine

  3. $C{l _2}{O _7}$ is an anhydride of perchloric acid

  4. ${O _3}$ molecule is bent

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Correct Option: A

The bond order in $N _{2}$ is 

chemistry chemical bonding and structure formal charge basics of chemical bonding types of bonds

  1. 2

  2. 2.5

  3. 1.5

  4. 3

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Correct Option: D

Formal charge on nitrogen in $NO _{3}^{-}$ ion is

chemistry chemical bonding and structure formal charge basics of chemical bonding types of bonds

  1. $+1$

  2. $+2$

  3. $+5$

  4. $Zero$

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Correct Option: A

The formal charge on the O atoms in the ion $[:\ddot{O} = N = \ddot{O}:]^+$ is:

chemistry chemical bonding and structure formal charge basics of chemical bonding types of bonds

  1. $-2$

  2. $-1$

  3. $0$

  4. $+1$

Show answer
Correct Option: C
Explanation:

Formal charge$=$Valence electrons-non bonding electrons+no of bonds$ =6-(4+2)=0$

In the cyanide ion the formal negative charge is on:

chemistry chemical bonding and structure formal charge basics of chemical bonding types of bonds

  1. $C$

  2. $N$

  3. both $C$ and $N$

  4. resonate between $C$ and $N$

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Correct Option: D
Explanation:

In the cyanide ion the formal negative charge resonates between $C$ and $N$. Cyanide ion has resonating structure, $-\overset { \ _ }{ C } \equiv N\longleftrightarrow \overset { \ _ }{ N } \underrightarrow { = } C$