MCQ Questions for Class 11 Medical Chemistry Chemical Bonding And Molecular Structure Quiz 12

The correct order of stability of

$Al^+,Al^{+2},Al^{+3}$ is:

0%
$Al^{+3}>Al^{+2}>Al^+$
0%
$Al^{+2} > Al^{+3} > Al^+$
0%
$Al^{+2} < Al^+ > Al^{+3}$
0%
$Al^{+3} > Al^+ > Al^{+2}$

Bond-length of

$HCl$ is

$1.275 \overset oA$

$(e=4.8$

$\times 10 ^{ -10 }$ e.s.u.). If dipole moment

$=1.02 D$ then

$HCl$ is:

0%
$100\%$ ionic
0%
$83\%$ covalent
0%
$50\%$ covalent
0%
$40\%$ ionic

The hybridisation of each carbon in the following compound is:

$\underset {i}{CH_{3}} - \underset {ii}{\overset {\overset {O}{||}}{C}} - \underset {iii}{CH_{2}} - \underset {iv}{CN}$

0%
$sp^{3}\ sp^{2}\ sp^{3}\ sp$
0%
$sp^{3}\ sp^{3}\ sp^{2}\ sp$
0%
$sp^{3}\ sp\ sp^{3}\ sp^{2}$
0%
$sp^{3}\ sp^{2}\ sp\ sp^{3}$

Explanation

$\underset {i}{CH_{3}} - \underset {ii}{\overset {\overset {O}{||}}{C}} - \underset {iii}{CH_{2}} - \underset {iv}{CN}$

In (i), all single bonds occur therefore

$sp^{3}$ hybridization.

In (ii), one double bond occurs therefore

$sp^{2}$ hybridization.

In (iiI), all single bond occurs therefore

$sp^{3}$ hybridization.

In (iv), one triple bond occurs, therefore

$sp$ hybridization.

Arrange the molecule in the increasing order of bond angle.

0%
${ H }_{ 2 }O< O{ F }_{ 2 }< O{ Cl }_{ 2 }$
0%
$O{ Cl }_{ 2 }< { H }_{ 2 }O< O{ F }_{ 2 }$
0%
$O{ F }_{ 2 }< O{ Cl }_{ 2 }< { H }_{ 2 }O\quad$
0%
$O{ F }_{ 2 }<{ H }_{ 2 }O< O{ Cl }_{ 2 }$

Explanation

$H_{2}O< OF_2<OCl_2$

$OCl_2$ have a maximum bond angle as the size of

$Cl$ atom is bigger due to which

$2\ Cl$ atom repel each other, thus have bigger bond angle than

$H_{2}O$ and

$OF_2$ .

Correct sequence of repulsion is:

0%
Lone pair (LP)-Lone pair $>$ Lone pair-bond pair (BP) $>$ B.P $-$ B.P
0%
B.P-B.P $>$ B.P-L.P $>$ L.P-L.P
0%
B.P-B.P $>$ L.P.-L.P. $>$ BP-LP.
0%
double bond-single bond $<$ single bond-single bond $<$ LP.-LP.

Which of the following is not the correct representation of sigma bond?

Explanation

$\sigma$ bond is formed by the coaxial overlapping of the two orbitals.

The

$\pi$ bond is formed by the lateral overlapping of the two orbital.

Thus, the overlapping in option D is not a sigma bond.

The number of

$\sigma$ and

$\pi$ bonds in orange azo dye is:

0%
$27$ and $5$
0%
$24$ and $7$
0%
$26$ and $7$
0%
$26$ and $6$

Explanation

1 single bond (-) contains 1

$\sigma$ bond and 1 double bond consists of 1

$\sigma$ and 1

$\pi$ bond.

The number of

$\sigma$ and

$\pi$ bonds in orange azo dye (p-hydroxyazobenzene) is

$26$ and

$7$ .

Hence, option C is correct.

Among the following, the molecules with the lowest dipole moment is

In which of the following compound Cl-atom is involved in H-bonding ?

0%
Chloral $(CCl_3 \, - \, CHO)$
0%
p-chlorophenol
0%
o-chlorophenol
0%
Hydrochloric acid

Explanation

In all the above structures, hydrogen bonding is performed by

$Cl$ atom.
1157044_877025_ans_03209c5769164040b98488ea6f9ebb4c.png

Which of the following overlap provides strongest bond?

0%
$s{ p }^{ 3 }-s{ p }^{ 3 }$
0%
$p-p$
0%
$s-s$
0%
$s-p$

Explanation

$sp^{3}$ has high quantity of

$p-$ character and we know that

$p-$ orbital is directiona and hence, it would more overlap than

$s-$ orbital.

$\therefore$ Have more bond strength than others.

Which of the following has been arranged in order of decreasing dipole moment?

0%
$CH_3Cl> CH_3F> CH_3Br>CH_3I$
0%
$CH_3F> CH_3Cl> CH_3Br> CH_3I$
0%
$CH_3Cl> CH_3Br>CH_3I> CH_3F$
0%
$CH_3F> CH_3Cl> CH_3I> CH_3Br$

Explanation

$CH_{3}F$ has the highest dipole moment due to its highest electronegativity but due to its smallest size it is unstable and

$CH_{3}Cl$ outlooks

$CH_{3}F$ .

Hence,

$CH_3Cl$ has the highest dipole moment . Below that comes

$CH_3F$ and below it decreases from

$Br$ to

$I$ as we go down a group because electronegativity also decreases as we go down a group.

Which of the following compound has highest dipole moment?

The percentage ionic character of a bond having

$1.257A^0$ its length and

$1.03$ D its dipole moment is:
(

$q = 4.8 \times 10^{-10}$ esu)

0%
$10\%$
0%
$15\%$
0%
$16.83\%$
0%
$18.88\%$

Explanation

$\mu_{ionic}(ionic\,dipole)=4.8\times 10^{-10}\times 1.275\times 10^{-8}$

$\mu_{ionic}=6.12\times10^{-18} esu\, cm$ =

$6.12\,D$

Observed dipole moment

$\mu_{observed}=1.032\,D$

% ionic character =

$\frac{\mu_{observed}}{\mu_{ionic}}\times 100$

$\frac{1.032\,D}{6.12\,D}\times 100$

$16.38\%$

Which one the following has the smallest dipole moment?

0%
1-Butene
0%
Cis-2-Butene
0%
Trans-2-Butene
0%
2-methyl-propene

Explanation

Dipole moment will be smallest in

$1$ as only

$1$ ethyle group is attached which is increasing the

$e^{-}$ density on the

$c=c$ .

$II$ being

$cis$ has more dipole moment due to

$2-CH_{3}$ groups are there.

$III$ dipole moment=

$O$ ; due to the alignment of

$CH_{3}$ groups.

$IV$ has maximum dipole moment due to the presence of

$2-CH_{3}$ groups on one carbon of

$c=c$ .

Identify correct order of average molecular dipole moment.

0%
$P{Cl}_{3}{F}_{2}> {N}_{2}{O}_{4(g)}> {N}_{2}{O}_{4(s)}$
0%
$P{Cl}_{3}{F}_{2}< {N}_{2}{O}_{4(g)}< {N}_{2}{O}_{4(s)}$
0%
$P{Cl}_{3}{F}_{2}< {N}_{2}{O}_{4(g)}= {N}_{2}{O}_{4(s)}$
0%
All are incorrect.

Explanation

Correct Option

$- D$

Reason:-

$PCl_{3}F_{2}$ has a symmetrical & thus has a zero dipole moment. Increasing dipole moments N from

$N_{2}O_{4}$

$_{(s)}$ to

$N_{2}O_{4}$

$_{(g)}$ is due to the fact that dipole moment=charge*distance.

The dipole moment of HBr is

$1.6\times 10^{-30}$ c.m. and inter atomic spacing is

$1\overset{o}{A}$ . The percentage ionic character of HBr is:

0%
$10$
0%
$0$
0%
$15$
0%
$27$

Explanation

Percentage of ionic character =

$\dfrac { Observed\ dipole\ moment }{ Calculated\ dipole\ moment } \times 100$

Observed dipole moment

$=1.6\times { 10 }^{ -30 }cm$

Calculated dipole moment = electron charge

$\times$ interatomic distance

$=1.6\times { 10 }^{ -19 }\times { 10 }^{ -10 }\\ =1.6\times { 10 }^{ -29 }cm$

% of ionic character

$=\dfrac { 1.6\times { 10 }^{ -30 } }{ 1.6\times { 10 }^{ -29 } } \times 100=10$

$\therefore$ Percentage of ionic character in

$HBr$ is

$10$

The number

$sp^2 - sp^2$ sigma bonds in the compound given below is:

0%
1
0%
3
0%
4
0%
5

Explanation

There are 8

$sp^2$ hybridized carbon atoms in the given compound which form 4

$sp^2-sp^2$ sigma bond with each other.

Thus, the correct answer is 4.

The dipole moments of halo compounds are in the order:

0%
$CHCl_3 > CCl_4 > CH_2Cl_2 > CH_3Cl$
0%
$CH_3Cl > CHCl_3 > CH_2Cl_2 > CCl_4$
0%
$CH_3Cl > CH_2Cl_2 > CHCl_3 > CCl_4$
0%
$CHCl_3 > CH_2Cl_2 > CH_3Cl > CCl_4$

Which molecule contains both polar and nonpolar covalent bond?

0%
$NH_4Cl$
0%
$HCN$
0%
$CH_4$
0%
$H_2O_2$

Minimum dipole moment containing compound is:

Which of the following will show least dipole character?

0%
Water
0%
Ethanol
0%
Ethane
0%
Ether

Isostructural species are those which have the same shape and hybridisation. Among the given species, identify the isostructural pairs.

0%
[ $NF_3$ and $BF_3$ ]
0%
[ $BF_4^-$ and $NH_4^+$ ]
0%
[ $BCl_3$ and $BrCl_3$ ]
0%
[ $NH_3$ and $NO^-_3$ ]

Explanation

From the structural point of the view, we see that,

$NF_{3}$ is pyramidal whereas $BF_{3}$ is planar triangular in structure.

$BF^{-}_{4}$ and $NH^{+}_{4}$ ions both are tetrahedral in structure.

$BCl_{3}$ is triangular planar whereas $BrCl_{3}$ is pyramidal in structure.

$NH_{3}$ is pyramidal whereas $NO_{3}$ is triangular planar structure.

So as we can see the only option B has both the elements same in structure.

The correct answer is option B.

If a molecule

$MX_3$ has zero dipole moment, the sigma bonding orbitals used by

$M$ (atomic number

$< 21$ ) are:

0%
pure $p$
0%
$sp$ hybrid
0%
$sp^2$ hybrid
0%
$sp^3$ hybrid

Explanation

If dipole moment is zero in

${ MX }_{ 3 }$ , then the bond angle is

$120°$ . There should be no lone pair on central atom and

$3$ bounds surrounded to it. One

$'s'$ and

$2'p'$ orbitals are included. So hybridisation is

${ sp }^{ 2 }$ .

Example,

${ BF }_{ 3 }$ .

The number and type of bonds between two carbon atoms in calcium carbide are :

0%
one sigma, one pi
0%
one sigma, two pi
0%
two sigma, one pi
0%
two sigma, two pi

Explanation

$Ca{ C }_{ 2 }$ is represented as

$\left[ :C\equiv C: \right] ^{ -2 }{ Ca }^{ +2 }$ .

It has one sigma bond and two

$pi$ bonds.

Hence, the correct option is B.

$\triangle$ H of which of the following reaction is zero?

0%
${ H }_{ 2 }\left( g \right) \rightarrow { 2H }^{ + }\left( g \right) +{ 2e }^{ - }$
0%
$2H\left( g \right) +aq\rightarrow { 2H }^{ + }\left( aq \right) +{ 2e }^{ - }$
0%
$2H\left( g \right) \rightarrow { 2H }^{ + }\left( g \right) +{ 2e }^{ - }$
0%
${ H }_{ 2 }\left( g \right) +aq\rightarrow { 2H }^{ + }\left( aq \right) +{ 2e }^{ - }$

Explanation

For electron displacement reactions of native state elements,

$\triangle H=0$ ,

Here

${ H }_{ 2 }$ is a native state element.

${ H }_{ 2 }(g)+aq\longrightarrow 2{ H }^{ + }(aq)+{ 2e }^{ - }$

The total number of lone pairs of electrons in

$N_2O_3$ is:

0%
6
0%
8
0%
5
0%
none of these

Explanation

${ N }_{ 2 }{ O }_{ 3 }$ has

$'8'$ lone pair according to its structure.
1158240_1044500_ans_2554c6ef6383488e843d700186114ab2.png

Which of the following statement is correct?

0%
Sigma bond is weaker than pie-bond
0%
$HF$ is less polar than $HI$
0%
In $NH^+_4$ ions $4$ coordinate bond is present
0%
In $SF_6$ all $S-F$ bond length are same

Explanation

${ SF }_{ 6 }$ , all the

$S-F$ bonds are equivalent and all bonds are of the same length.

The sigma bond is stronger than the pi-bond. This is because in sigma bond co-axial bonding overlap of the orbital takes place whereas in a pi-bond lateral overlapping of the orbital takes place.

$HF$ is more polar than the

$HI$ as the electronegativity difference between

$H$ and

$F$ is more than

$H$ and

$I$ .

$NH_4^+$ , there is only one coordination bond between

$H_3N:$ and

$H^+$ .

983116_1034948_ans_0e6e118fe5e44801becbe489d88e4012.png

The compound with no dipole moment is:

0%
methyl chloride
0%
carbon tetrachloride
0%
methylene chloride
0%
chloroform

Explanation

${ CCl }_{ 4 }$

The Chlorines are electron withdrawing groups and

$CCl_4$ is symmetric molecule. One side cancels the other side dipole moment. So dipole moment is zero.

980798_1042234_ans_8301b18b08cb4ea095e1f12e43ff64af.png

Which of the following molecules\ions does not contain unpaired electrons?

0%
$N^+_2$
0%
$O_2$
0%
$O^{2-}_2$
0%
$B_2$

Explanation

The molecular orbital diagram of

${ O }_{ 2 }^{ -2 },{ \pi }^{ \ast }2Px$ and

${ \pi }^{ \ast }2Py$ molecular orbitals are completely filled , which are partially filled in

${ O }_{ 2 }$ . These are no unpaired electrons. So,

${ O }_{ 2 }^{ -2 }$ does not contain unpaired electrons.

Arrange the following compounds in order of increasing dipole moment :

Toluene (I)
m- dichlorobenzene (II)
o-dichlorobenzene (III)
p- dichlorobenzene (IV)

0%
I < IV < II < III
0%
IV < I < II < III
0%
IV < I < III < II
0%
IV < II < I < III

Following is a diagram representation of standard reduction potential values. Which out of the following undergo disproportionation?

0%
$Cl{O^ - }$
0%
$C{l_2}$
0%
$Cl{O_2}$
0%
$ClO_3^ -$

In the given reaction:

${ \left[ Co{ \left( { NH }_{ 3 } \right) }_{ 5 }{ H }_{ 2 }O \right] }^{ 2+ }+{ NH }_{ 3 }\longrightarrow compound(Y)+{ e }^{ - }+{ H }_{ 2 }O$
Compound (X)
Number of unpaired electron in compound X and compound Y are respectively:

0%
$(1,0)$
0%
$(3,1)$
0%
$(1,3)$
0%
$(3,3)$

Explanation

${ \left[ Co{ \left( { NH }_{ 3 } \right) }_{ 5 }{ H_2O } \right] }^{ 2+ }\rightarrow { d }^{ 7 }$

$\left( X \right)$

$\rightarrow$ low spin

$\rightarrow$ No. of unpaired

${ e }^{ - }=1$

${ \left[ { \left( { Co(NH }_{ 3 })_6\right) }\right] }^{ 3+ }\rightarrow { d }^{ 6 }$

$\left( Y \right)$

$\rightarrow$ low spin

$\rightarrow$ No. of unpaired

${ e }^{ - }=0$

985974_1068123_ans_edfa7a6503924d339c4212534b48781b.jpg

Which conformation has non-zero dipolemoment?

Explanation

In para-dihydroxybenzene or para-hydroxyphenol the dipole moment is not along

$-C-O$ axis, but rather at some angle to that axis, so that group substituents at opposite directions in the ring, do not oppose the bond moments directly.

The

$C-O-H$ bond angle is close to

$90^o$ . Arrangement of H is not symmetrical about the line of attachment of the group.

975833_1048632_ans_9d172cabc5f8488bbcaa56c331281cc2.png

Bonds and lone pairs present in enolic form of butanone are?

0%
$12\sigma$ bonds, $1\pi$ bond and $2$ lone pairs of electrons
0%
$11\sigma$ bonds, $1\pi$ bond and $2$ lone pairs of electrons
0%
$12\sigma$ bonds, $1\pi$ bond and $1$ lone pairs of electrons
0%
$10\sigma$ bonds, $2\pi$ bond and $2$ lone pairs of electrons

A certain diatomic molecule,

$AB$ has dipole moment

$1.6D$ and the inter-nuclear distance is

$100pm$ . The percentage of electronic charge existing on more electronegative atom is:

0%
$33$ %
0%
$25$ %
0%
$50$ %
0%
$10$ %

Explanation

% of ionic character= observed ionic × 100observed =

$1.6 D$ =

$1.6 × 10−30 cm (since 1 D = 10−30 cm)$

$ionic = q × d q = 4.8 × 10−10$

$esu = 4.8 × 108 D = 4.8 × 108× 10−30 cm (since 1D = 10−18 esu)$

$d = 100 pm = 100 × 10−10 cm$

$% ionic character = observed ionic × 100 = 1.6 × 10−30$

$4.8 × 108× 10−30× 100 × 10−10 × 100 = 33.33 %$

Therefore,

$33.33%$ is the answer.

Select the correct statement.

0%
$C$ is basic, whereas ${ \left( C{ F }_{ 3 } \right) }_{ 3 }N$ is not
0%
$PbCl_{2}$ melts at $606^{o}\ C$ . whereas $PbCl_{4}$ melts at $114^{o}\ C$ .
0%
$NaCl$ is soluble is petrol
0%
Dipole moment of $BF_{3}$ is high

Explanation

$(A)$ in correct option

At in

$(CF_3)_2 N$ flurline is present the electrogravity if which is quir high as compared to hydrogen so it's quality attract the electron pair towards it self and lenier the electron per

$m$ the nitrogen which is unity they are in basic.

$(B)$ correct option

$PbCl_2$ is ionic solid when can

$PbCl_4$ is covalent character type compound so

$PbCl_2$ high molarity point

$(C)$ Incorrect option

$NaCl$ is ionic and petrol is covalent

$(D)$ Incorrect option

Dipole moment it

$Bl_3$ is

$O$

Which one of the following dipole moment order is correct?

0%
$CCl_4 > CH_2Cl_2 > CH Cl_3 > CH_3Cl$
0%
$CH_3Cl > CH_2Cl_2 > CH Cl_3 > CCl_4$
0%
$CH_2Cl _2> CH_3Cl > CH Cl_3 > CCl_4$
0%
$CHCl _3> CH_2Cl_2 > CH_3 Cl > CCl_4$

When 2-butyne is treated with

$H_2/$ Lindlar's catalyst, compound

$X$ is produced as the major product and when treated with

$Na/$ liq.

$NH_3$ it produces

$Y$ as the major product. Which of the following statements is correct?

0%
$X$ will have higher dipole moment and higher boiling point than $Y$
0%
$Y$ will have higher dipole moment and higher boiling point than $X$
0%
$X$ will have lower dipole moment and lower boiling point than $Y$
0%
$Y$ will have lower dipole moment and lower boiling point than $X$

Explanation

As we learnt,

Birch Reduction:

Alkynes on reduction with sodium in liquid

${ NH }_{ 3 }$ form trans alkene where in

Reduction of alkynes.

Proceeds via two single electron transfer from

$Na$ to alkyne each followed by protonation with

${ NH }_{ 3 }$ .

Cis have higher dipole moment than trans option

$1$ is correct. i.e,

$X$ will have higher dipole moment and higher boiling point than

$Y$ .

1197555_1121775_ans_9a8e9be48cab4933959f678d52eb00c5.jpg

When

${O}_{2}$ is converted into

${O}_{2}^{+}$

0%
both paramagnetic character and bond order increases
0%
bond order decreases
0%
paramagnetic character increases
0%
paramagnetic character decreases and the bond order increases

The dipole moment of hydrogen chloride with bond distance

$1.27A^o$ is

$1.03\ D$ . The percent ionic character of its bond is?

0%
$15$
0%
$17$
0%
$19$
0%
$21$

Which of the following compound has

$\mu =0$ ?

0%
$CCl_4$
0%
$CHCl_3$
0%
$HF$
0%
$NH_3$

Number and type of bonds between two carbon atom in

$CaC_{2}$ are :

0%
$one (\sigma )\ and\ one(\pi )\ bonds$
0%
$one (\sigma )\ and\ two(\pi )\ bonds$
0%
$3 (\sigma)\ and 2(\pi )\ bonds$
0%
$one (\sigma)\ bond$

Dipole moment of

$H_2O$ is

$1.84 D$ .If the bond angle is

$105^o$ and

$O-H$ bond length is

$0.94 AA$ ,what is the magnitude of charge on the atom in water molecules?

0%
$2\times10^{-10}$ esu
0%
$3.28\times10^{-10}$ esu
0%
$3.22\times10^{-10}$ esu
0%
$1.602\times10^{-19} C$

The molecule which have zero dipole moment is

0%
${CH}_{2}{Cl}_{2}$
0%
${BF}_{3}$
0%
${NF}_{3}$
0%
${IF}_{3}$

Dipole moment is shown by?

0%
1, 2-dichlorobenzene
0%
trans 2, 3-dichloro-2-butene
0%
1, 4-DIchlorobenzene
0%
trans-1, 2-dinitroethene

Explanation

Hint: The same group in the opposite direction cancels the dipole moment.

Correct Answer: Option A

Explanation for Correct Option:

Dipole moment is the product of the magnitude of the charge and the distance between the centers of the positive and negative charges
In 1, 2 dichlorobenzene the two dipoles are at $60$ Degree (i.e. unsymmetric).
Thus possesses dipole moment.

Explanation for Incorrect Option:
Option B:

In the case of trans

$2, 3-dichloro-2-butene$ two

$Cl$ are in opposite directions hence they cancel the dipole moment.
So, the Overall dipole is zero.

Option C:

Both chlorine is on opposite side hence no dipole moment.

Option D:

In this case, both nitro group is in the opposite direction so they cancel each other

Dative bond is not present in ?

0%
$NH_{4}^{+}$
0%
$N_{2}O$
0%
$BCl_{3}$
0%
$B_{3}N_{3}H_{6}$

Consider the following three halides:
(i)

${CH}_{3}-{CH}_{2}Cl$
(ii)

${CH}_{2}=CH-Cl$
(iii)

${C}_{6}{H}_{5}-Cl$
Arrange

$C-Cl$ bond lenght of these compounds in decreasing order:

0%
$i> ii> iii$
0%
$i> iii> ii$
0%
$iii> ii> i$
0%
$ii> iii> i$

A reagent which lowers the oxidation number of an element in a given substance is known as

0%
oxidation agent
0%
reduction
0%
reducing agent
0%
oxidation

Which of the following has zero dipole

0%
${BF}_{3}$
0%
$BeClBr$
0%
${CH}_{2}{Cl}_{2}$
0%
$COS$

The

$X-X$ bond length is

$1.00\mathring{A}$ and

$C-C$ bond length is

$1.54\mathring{A}$ . The

$C-X$ bond length is likely to be

0%
$0.80\mathring {A}$
0%
$1.18\mathring {A}$
0%
$1.57\mathring {A}$
0%
$1.68\mathring {A}$

CBSE Questions for Class 11 Medical Chemistry Chemical Bonding And Molecular Structure Quiz 12 - MCQExams.com

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Practice Class 11 Medical Chemistry Quiz Questions and Answers

CBSE Questions for Class 11 Medical Chemistry Chemical Bonding And Molecular Structure Quiz 12 - MCQExams.com

0:0:2

Practice Class 11 Medical Chemistry Quiz Questions and Answers

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