MCQ Questions for Class 11 Engineering Chemistry Some P-Block Elements Quiz 6

Which of the following compound is a gas (at

$0^{\circ}C$ ) ?

0%
$BF_3$
0%
$BCI_3$
0%
$BBr_3$
0%
$BI_3$

Explanation

	Mp(°C)	Bp(°C)
$BF_3$	-126.8	-100.3
$BCl_3$	-107.3	12.6
$BBr_3$	-46.3	91.3
$BI_3$	49.9	210

$\displaystyle 0^0C$ ,

$\displaystyle BF_3$ is a gas whereas

$\displaystyle BCl_3$ and

$\displaystyle BBr_3$ are liquids and

$\displaystyle BI_3$ is a solid.

From the

$B_2 H_6$ , all the following can be prepared except:

0%
$H_3 BO_3$
0%
$[BH_2(NH_3)_2]^{+} [BH_4]^{-}$
0%
$B_2(CH_3)_6$
0%
$NaBH_4$

Explanation

${ B }_{ 2 }{ H }_{ 6 }+6{ H }_{ 2 }O\rightarrow 2B\left( OH \right) _{ 3 }+6{ H }_{ 2 }\\ { B }_{ 2 }{ H }_{ 6 }+2N{ H }_{ 3 }\rightarrow [{ BH }_{ 2 }\left( { NH }_{ 3 } \right) _{ 2 }]^{ + }[{ BH }_{ 4 }]^{ - }\\ { 2B }_{ 2 }{ H }_{ 6 }+2Na\rightarrow { NaBH }_{ 4 }+Na{ B }_{ 3 }{ H }_{ 8 }$

Which of the following is a allotrope of carbon?

0%
Diamond
0%
Graphite
0%
Fullerenes
0%
Silica

When orthoboric acid

$(H_3BO_3)$ is heated the residue left is:

0%
Boron
0%
Metaboric acid
0%
Boric anhydride
0%
Borax

Explanation

B. Metaboric acid
Boric acid when heated above 170C it dehydrates forming metaboric acid. Metaboric acid when heated above 300C it further dehydrates forming pyroboric acid.

${ H }_{ 3 }{ BO }_{ 3 }\rightarrow { HBO }_{ 2 }+{ H }_{ 2 }O\\ { 4HBO }_{ 2 }\rightarrow { H }_{ 2 }{ B }_{ 4 }{ O }_{ 7 }+{ H }_{ 2 }{ O }$

Correct trend of first lonisation energy in group 13 is:

0%
$\displaystyle B> Tl> Ga> Al> In$
0%
$\displaystyle B> Al> Ga> Tl> In$
0%
$\displaystyle B> Tl> Ga> Al> In$
0%
$\displaystyle B> Ga> Al> In> Tl$

What does P, Q & R represent in the given figure of nitrogen cycle ?

0%
P Ammonia Q Nitrates R Nitrites
0%
P Ammonia Q Nitrites R Nitrates
0%
P Nitrites Q Nitrates R Ammonia
0%
P Nitrates Q Nitrites R Ammonia

(a) Silicone is a polymeric organo silicon compound which is chemically inert and thermally stable
(b) Silicon carbide can be used as a lubricant.
(c) Silicon dioxide is the raw material for the manufacture of cement as well as glass.
(d) Hardness of

$Si{O}_{2}$ and

$SiC$ is due to their regular tetrahedral structure.

Which of the following regarding silicon and its compounds is correct?

0%
a and b
0%
b and c
0%
a, c and d
0%
only d

Explanation

Silicones are polymers that include any inert, synthetic compound made up of repeating units of siloxane, which is a functional group of two silicon atoms and one oxygen atom frequently combined with carbon and/ or hydrogen. Silicon carbide found in the form of powder and grains. Silicon dioxide is the raw material for the manufacture of cement as well as glass Hardness of

$SiO_2$ and

$SiC$ is due to tetrahedral

$sp^3$ bonds, one might expect the diamond structure

An ecologist studied the effects of sewage effluent on the levels of oxygen concentration, bacterial population and algal growth in a fresh water stream. The given graph is plotted based on his findings.
select the correct statement regarding the given graph.

0%
There is a fall in oxygen concentration between point Y and 4 km downstream because it is utilized by algae for respiration during day.
0%
There is a rise in oxygen concentration between 4 km and 8 km downstream because of oxygen for respiration is lower
0%
Bacterial population never recovers from 8 km onwards because all the oxygen is used by algae
0%
There is decrease in the level of bacteria between 5 km and 7 km downstream because all the oxygen and organic matter has been used up by algal population

Which of the following is a water-borne disease :

0%
Malaria
0%
Dysentery
0%
Pneumonia
0%
Breathlessness

Elements of group 14 :

0%
exhibit oxidation state of +4 only
0%
exhibit oxidation state of +2 and +4
0%
form $M^2$ and $M^{4+}$ ions
0%
form $M^{2+}$ and $M^{4+}$ ions

Explanation

Elements of group 14, having outer electronic configuration

$ns^2np^2$ show +2 and +4 oxidation states.
On moving down the group, the stability of +2 oxidation state increases and the stability of +4 oxidation state decreases.

Pnicogens are the elements of group:

0%
$15$
0%
$13$
0%
VIII
0%
Zero

Explanation

Members of group

$15$ or VA of Periodic Table are called pnicogens. They include

$N,\ P,\ As,\ Sb$ and

$Bi$ .

An aqueous solution of borax is :

0%
neutral
0%
amphoteric
0%
basic
0%
acidic

Explanation

$\bf{Hint:}$ An aqueous solution which contains excess

$OH^{-}$ ions are basic in nature.

$\bf{Explanation:}$

Borax also called as sodium tetraborate and its chemical formula is

$Na_2B_4O_7$ .

The complete reaction of borax with water is as shown below;

$\bf\displaystyle Na_2B_4O_7+7H_2O \rightarrow 2NaOH+4H_3BO_3$

In the reaction, there is a formation of sodium hydroxide

$NaOH$ which is a strong base, and boric acid

$H_3BO_3$ which is a weak acid.
As there is a strong base and weak acid formed in the reaction overall solution becomes basic in nature.

$\bf{Final \ answer:}$ Option

$C$

In diborane, the two H-B-H angles are nearly :

0%
$60^o, 120^o$
0%
$90^o, 120^o$
0%
$95^o,150^o$
0%
$120^o, 180^o$

Explanation

In diborane, the bonds between boron and the terminal hydrogen atoms are conventional 2-center, 2-electron covalent bonds. The two

$H-B-H$ angles are nearly

$90^o and \ 120^o$ .

Order of reactivity of halogen acids towards an alcohol is:

0%
HCl > HBr > HI
0%
HBr > HI > HCl
0%
HI > HBr > HCl
0%
HI > HCl > HBr

Explanation

Longer the bond length, lesser will be dissociation energy and hence, more reactivity.
Among halogen acids bond length increases from HCl to HI.

$\therefore$ Order of reactivity of halogen acids towards alcohol is

$HI > HBr > HCl$

Coordination number of aluminium is:

0%
8
0%
6
0%
12
0%
4

Explanation

Write valence shell configuration of

$Al$ .

$Al(13) = 1s^2, 2s^22p^6, 3s^23p^1$

$\therefore$ It can have maximum coordination number as 6

Which of the following is known as dead burnt?

0%
Gypsum
0%
Plaster of Paris
0%
Anhydrite
0%
None of these

Explanation

$\underset {gypsum}{CaSO_{4}\cdot 2H_{2}O} \xrightarrow {120^{\circ}} \underset {\text {Plaster of paris}}{CaSO_{4}\cdot 1/2H_{2}O} \xrightarrow {200^{\circ}C} \underset {\text {anhydrite or dead burnt plaster}}{CaSO_{4}}$
The anhydrous

$CaSO_{4}$ is called dead burnt plaster because it does not set like plaster of Paris when moistened with water.

Apatite is an ore of:

0%
fluorine.
0%
chlorine.
0%
bromine.
0%
iodine.

Explanation

Apatite is

$CaF_{2} \cdot 3Ca_{3}(PO_{4})_{2}$

$\therefore$ It is an ore of fluorine with calcium.

Which of the following forms vortex ring?

0%
$P_{2}O_{5}$
0%
$PH_{3}$
0%
$NH_{3}$
0%
$P_{2}O_{10}$

Explanation

Phosphine forms vortex rings of

$P_{2}O_{5}$ when it comes in contact of air. These rings are in form of white smoke.

$\therefore$ They are used in making smoke screens in warfare.

The stable bivalency of

$Pb$ and trivalency of

$Bi$ is :

0%
due to d contraction in $Pb$ and $Bi$
0%
due to relativistic contraction of the $6s$ orbitals of $Pb$ and $Bi$ , leading to inert pair effect
0%
due to screening effect
0%
due to attainment of noble liquid configuration

Explanation

83Bi=6s26p3

${ Pb=6s }^{ 2 }{ 6p }^{ 2 }\\ { Bi=6s }^{ 2 }{ 6p }^{ 3 }\\$

Due to inertness of

$6{s}^2$ electrons in

PbPb and

BiBi, they show bivalency and trivalent respectively instead of tetravalent and pentavalency.

Argyrodite, briartite contain appreciable amounts of _____?

0%
lead
0%
germanium
0%
zinc
0%
copper

All hydrocarbons contain _____.

0%
carbon
0%
germanium
0%
antimony
0%
water

Diamond is a allotrope of _______.

0%
carbon
0%
lead
0%
antimony
0%
germanium

In clatherates of xenon with water, the nature of bonding between xenon and water molecule is :

0%
Dipole induced dipole interaction
0%
Coordinate
0%
Hydrogen bonding
0%
Covalent

A Si and a Ge diode has identical physical dimensions. The band gap in Si is larger than that in Ge. An identical reverse bias is applied across the diodes

0%
The reverse current in Ge is larger than that in Si
0%
The reverse current in Si is larger than that in Ge
0%
The reverse current is identical in the two diodes
0%
The relative magnitude of the reverse currents cannot be determined from the given data only

Which of the following shows bond in silicone?

0%
$Si-C-Si-C-Si$
0%
$Si-Si-Si-Si$
0%
$-Si-O-Si-O-Si$
0%
$Si-C-Si-O-Si$

Explanation

Silicones are organic silicon polymers containing

$Si-O-Si$ linkages.

Hence, option

$C$ is correct.

Which of the following metals has the largest abundance in the earth's crust?

0%
Aluminium
0%
Calcium
0%
Magnesium
0%
Sodium

Boiling point increases in order

$CH_4$ <

$SH_4$ <

$GeH_4$ because :

0%
atomic number of central metal atom increases
0%
molecular mass increases
0%
dipole - dipole interaction increases
0%
bond length increases

Explanation

Boiling point increases in order

$CH_4 < SH_4 < GeH_4$
molecular mass increases. The atomic mass increases in the order

$C < S < Ge$ . Hence, the molecular mass increases in the same order.

Why carbon can form stable

$C = C$ bond where as silicon can't form

$Si = Si$ ?

0%
Poor overlap of $p\pi - d\pi$ in silicon
0%
Poor overlap of $p-s$ in silicon
0%
Poor overlap of $p\pi-s$ in silicon
0%
Silicon do not have vacant orbital

Explanation

Silicon can't form

$Si=Si$ due to poor overlapping of

$p\pi-d\pi$ bond. Si has no tendency to form double bonds with itself due to its large size. The bond formation is difficult du to the large size.

Which of the following correctly represents the variation of electronegativity (EN) with atomic number (Z) of group 13 elements?

Electronegativity of group 13 elements follow the order :

0%
B > Ca >Al > Th > In
0%
B > Th> Ga > Al > In
0%
B > Th> In > Ga > Al
0%
B > Al > Th > In > Ga

A type of ion found in aluminum oxide is :

0%
$X^+$
0%
$X^{2+}$
0%
$X^{3+}$
0%
$XO_3^{2-}$
0%
$XO_4^{2-}$

Explanation

A type of ion found in aluminum oxide is

$\displaystyle X^{3+}$ .
Aluminum oxide is

$\displaystyle Al_2O_3$ . It contains

$\displaystyle Al^{3+}$ ion and

$\displaystyle O^{2-}$ ion.

Heavier elements of p-block do show higher order oxidation state because of :

0%
lanthanide contraction
0%
inert pair effect
0%
screening effect
0%
absence of vacant d-orbital

Out of

$HClO, HBrO$ and

$HIO$ which one is most acidic :

0%
$HBrO$
0%
$HClO$
0%
$HIO$
0%
All are equally acidic

Explanation

$Cl$ is most electronegative out of

$Cl, Br,I$ , it will make the

$Cl-O$ bond more polar and weaker compared to

$Br$ and

$I$ .

Therefore,

$HClO$ will be most acidic.

Hence the correct option is B.

Which is only metal in group 15?

0%
Phosphorus
0%
Arsenic
0%
Antimony
0%
Bismuth

Explanation

Option

$(D)$ is correct.

Bismuth is only metal in group 15.

Phosphorus is non-metal, antimony and arsenic both are metalloids.

Which of the following do not have linear structure?

0%
$CO_2$
0%
$N_2O$
0%
$BeF_2$
0%
$SnCl_2$

Explanation

Option

$(D)$ is correct.

$SnCl_2$ do not have a linear structure. It has a lone pair of the electron due to which shape of molecule changes to angular i.e.

$V$ - shaped.

Hence the correct option is D.

$\displaystyle Al{ H }_{ 3 }$ is an example for :

0%
interstitial hydride
0%
electron rich hydride
0%
ionic hydride
0%
electron deficient hydride

Explanation

According to the Bohr's octet rule, each element tends to completely fill its outermost orbit with 8 electrons in it. Electronic configuration of aluminium is 2,8,3 that means it still needs 5 more electrons to complete its octet. That's why aluminium is electron deficient.

Hence, option

$D$ is correct.

Which of these forms nitride with nitrogen at higher temperature?

0%
Aluminium
0%
Boron
0%
Both $A$ and $B$
0%
Indium

Explanation

Option

$(C)$ is correct.

Aluminium and boron forms nitride with nitrogen at higher temperature due to the high bond energy of nitrogen. In case of aluminium, a thin oxide layer is formed so it also needs high temperature to react with nitrogen to form the nitride.

Amphoteric oxide is:

0%
$Al_2O_3$
0%
$SiO_2$
0%
$P_4O_{10}$
0%
$ClO_7$

Explanation

Explanation:

The chemicals which react with both acids and bases are called amphoteric oxides.
$Al_2O_3$ reacts with both acids as well as bases. So it is an amphoteric oxide.
$SiO_2$ , $P_4O_{10}$ and $ClO_7$ are acidic oxides, hence none of these three are amphoteric.
Therefore, $SiO_2$ , $P_4O_{10}$ and $Cl_2O_7$ are not amphoteric oxides.

Hence, the correct answer is option $A$ .

Why

$Bi^{3+}$ more stable than

$Bi^{+5}$ ?

0%
Due to inert pair effect
0%
Due to inert gas electronic configuration
0%
Due to half filled configuration
0%
Due to lanthanide Contraction

Explanation

Option

$(A)$ is correct.

$Bi^{3+}$ is more stable than

$Bi^{5+}$ due to inert pair effect. Ongoing down the group, inert pair effect increases due to more penetration of

$s$ - orbital in nucleus due to which element tends to show lower oxidation state more stable than higher oxidation state. Thus, bismuth will show a strong tendency to change into +3 state from +5 state.

Straight chain silicones are prepared by hydrolysis by:

0%
$R_2SiCl_2$
0%
$R_3SiCl$
0%
$RSiCl_3$
0%
$R_2Si$

Explanation

Hydrolysis of

$R_2SiCl_2$ gives straight chain that is linear silicones.

For example, if we consider

$R$ as

$-CH_3$ group, the molecule becomes

$(CH_3)_2SiCl_2$ , that is Dimethyldichlorosilane. On performing hydrolysis of this compound, we get.

$n(CH_3)_2SiCl_2$

$+$

$nH_2O$

$=$

$[(CH_3)_2SiO]_n$

$+$

$2nHCl$ , where

$n$ represents an integer or the number of moles.

$[(CH_3)_2SiO]_n$ are the straight chain silicones, that is compounds containing

$Si-O$ backbones. They are polymers.

Option A is the correct answer.

Which one of the following is paramagnetic in nature?

0%
$NO$
0%
$N_2O$
0%
$N_2O_5$
0%
All of the above

Explanation

Whenever two electrons are paired together in an orbital, or their total spin is 0, they are diamagnetic electrons. Atoms with all diamagnetic electrons are called diamagnetic atoms.

A paramagnetic electron is an unpaired electron. $NO$ has one unpaired electron. Hence, it is paramagnetic in nature.

Which of the following metal will give

$N_2O$ on reaction with dilute nitric acid?

0%
$Zn$
0%
$Cu$
0%
$Hg$
0%
$Ag$

Explanation

Concentrated nitric acid is a powerful oxidising agent, and its reaction with zinc involves a complicated set of redox reactions. However the primary product is still zinc nitrate.

$4Zn + 10HNO_3 \rightarrow 4Zn(NO_3)_2 + N_2O + 5H_2O$

Which of the following statement is correct?

0%
The 1st ionisation enthalpy of group 13 elements is less than that of group 2 elements
0%
The 1st ionization enthalpy of group 16 elements is more than of group 15 elements.
0%
Germanium is non-metal
0%
$ClO_7$ is amphoteric oxide

Explanation

The statement (A) is correct.

The 1st ionisation enthalpy of group 13 elements is less than that of group 2 elements.

$p$ electrons are less penetrating and more shielded than

$s$ electrons.

They are farther from the nucleus and hence held less tightly than the

$s$ electrons.

$p$ electrons can be easily removed.

Which of the following is not pseudo halogen?

0%
$(CN_2)$
0%
$(SCN_2)$
0%
$(OCN)_2$
0%
$H_2$

Explanation

Option $(D)$ is correct.

$H_2$ is not pseudo halogen compound.

The pseudohalogens are polyatomic analogues of halogens, whose chemistry, resembling that of the true halogens, allows them to substitute for halogens. They have a general formula of $Ps–Ps$ or $Ps–X$ (where $Ps$ is a pseudohalogen group), such as cyanogen, pseudohalide anions, such as cyanide ion. Well-known pseudohalogen functional groups include cyanide, cyanate, thiocyanate, and azide.

What is the oxidation state of nitrogen in

$N_2O_5$ ?

0%
5
0%
10
0%
4
0%
3

Explanation

Let the oxidation state of

$N$ be

$x$ . Oxidation state of

$O$ is

$-2$ as it is in oxide form.

$\Rightarrow 2x+5(-2)=0$

$\Rightarrow x=\dfrac{10}{2}=+5$

Phosphorus pentaoxide reacts with

$H_2O$ to form an acid. What is the basicity of that acid?

0%
1
0%
3
0%
2
0%
4

Explanation

Option

$(B)$ is correct.

Phosphorus pentaoxide reacts with

$H_2O$ to form phosphoric acid.

$P_2O_5 + 3H_2O \rightarrow 2H_3PO_4$

Basicity of phosphoric acid is 3.Basicity of an acid refers to the number of replaceable hydrogen atoms in one molecule of the acid

$H_3PO_4(aq) \rightarrow 3H^+(aq) + PO_4^{ 3-}(aq)$

At standard conditions_______ has an allotropic form that is a good electrical conductor.

0%
carbon
0%
nitrogen
0%
oxygen
0%
neon
0%
argon

Examples of silicate minerals in the crust include:

0%
pyroxene
0%
mica
0%
amphibole
0%
cassertite

Quartz,

$\displaystyle Si{ O }_{ 2 }$ , has a high melting point and is insoluble in most solvents. Which type of force best accounts for the physical properties of quartz?

0%
Hydrogen bonding
0%
Covalent bonding
0%
Ionic bonding
0%
Pi bonding
0%
Dispersion forces

The oxidation state(s) shared by each of the elements in group IV

$(C, Si, Ge, Sn$ and

$Pb)$ is/are

0%
$+2$
0%
$+4$
0%
$+2, +4$
0%
$-2, +2$

Explanation

$C$ ,

$Si$ ,

$Ge$ ,

$Sn$ and

$Pb$ can have both the oxidation states

$+2$ and

$+4$ .

Example can be given as oxidation state of Carbon in Carbon Monoxide, that is

$CO$ is

$+2$ . Whereas, oxidation state of Carbon in Carbon Dioxide, that is

$CO_2$ is

$+4$

Option C is the correct answer.

CBSE Questions for Class 11 Engineering Chemistry Some P-Block Elements Quiz 6 - MCQExams.com

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Practice Class 11 Engineering Chemistry Quiz Questions and Answers

CBSE Questions for Class 11 Engineering Chemistry Some P-Block Elements Quiz 6 - MCQExams.com

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Practice Class 11 Engineering Chemistry Quiz Questions and Answers

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