MCQ Questions for Class 11 Engineering Chemistry Some P-Block Elements Quiz 2

An element 'X' atomic number 51 belongs to ______.

0%
s-block
0%
p-block
0%
d-block
0%
f-block

Indite is a mineral for the production of ______.

0%
indium
0%
aluminium
0%
boron
0%
gallium

Explanation

Indite is an extremely rare indium-iron sulfide mineral, found in Siberia. Its chemical formula is

$Fe{In}_2S_4$ .

Pure air contains nitrogen, oxygen and small amounts of other gases. The noble gases have been left out of the table.
Which row shows the composition of dry, unpolluted air?

0%
nitrogen/ % - 21 ; oxygen/ % - 78; other gases - small amount of carbondioxide
0%
nitrogen/ % - 21 ; oxygen/ % - 78; other gases - small amount of carbon monoxide
0%
nitrogen/ % - 78 ; oxygen/ % - 21; other gases - small amount of carbon dioxide
0%
nitrogen/ % - 7 ; oxygen/ % - 21; other gases - small amount of carbon monoxide

Explanation

$\text{atmosphere contain}$

$\text{Nitrogen-78%}$

$\text{Oxygen-21%}$

Which has an electron configuration

$1s^{2}2s^{2}2p^{6}3s^{2}3p^{1}$ ?

0%
$Na^{+}$
0%
$Al$
0%
$F$
0%
$Ti$
0%
$B$

Explanation

Option

$(A)$ is correct.

$Al$ has an electron configuration

$1s^{2}2s^{2}2p^{6}3s^{2}3p^{1}$ .Atomic no. of aluminium is 13.

Tin metal exists in two allotropic forms.

0%
True
0%
False

Explanation

Allotropy is the property of chemical elements to exist in two or more different forms, in the same physical state, where they are called allotropes of the element.
Tin has two main allotropes: at room temperature, the stable allotrope is

$\beta$ -tin, a silvery-white, malleable metal, but at low temperatures it transforms into the less dense grey

$\alpha$ -tin, which has the diamond cubic structure. Metallic tin does not easily oxidize in air.
Statement is true. Option A is correct

Which of the following member of the carbon family does not have an allotrope?

0%
$Si$
0%
$Sn$
0%
$C$
0%
$Ge$

In the ground state the carbon atom has .... unpaired electron/ electrons:

0%
$2$
0%
$3$
0%
$4$
0%
$no$

Tincal contains mainly :

0%
$NaNO_{3}$
0%
$Na_{2}B_{4}O_{7}.10H_{2}O$
0%
$Na_{2}CO_{3}$
0%
$Na_{2}SO_{4}$

Explanation

Tincal mainly contains

$Na_2B_4O_7\cdot 10H_2O$ . It is borax or sodium tetraborate or sodium borate.

Which of the following is representative group of elements in the periodic table?

0%
Lanthanum
0%
Argon
0%
Chromium
0%
Aluminium

Which element has the highest valency with respect to oxygen?

0%
Sodium
0%
Aluminium
0%
Chlorine
0%
Sulphur

Which element show more pronounced inert pair effect?

0%
N
0%
Sn
0%
C
0%
Pb

The monomer units of silicons, a water repellant, acid resistant and heat resistant polymer, is:

0%
$Si$
0%
$SiO_{2}$
0%
$R_{2}Si(OH)_2$
0%
$RSiOH$

Explanation

Alkyl group is water repellent and acid as well as heat resistant because of high bond energy.

Hence, the monomer units of silicones as water repellant, acid-resistant and heat resistant polymer is

$R_2Si(OH)_2$ .

Therefore, option C is correct.

Non-metals present in borax are:

0%
$B$
0%
$O$
0%
both $O$ and $B$
0%
$Na$

Explanation

Borax is sodium tetraborate or sodium borate. Its formula is

$Na_2B_4O_7\cdot 10H_2O$ . It contains

$O$ and

$B$ non metals.

The element whose atomic volume is least is

0%
Boron
0%
Aluminum
0%
Gallium
0%
Thallium

Silicon is an important constituent of:

0%
chlorophyll
0%
haemoglobin
0%
rocks
0%
amalgams

The least abundant element of IV A group is :

0%
C
0%
Si
0%
Ge
0%
Pb

Explanation

The least abundant element of IV A group is Ge.
The decreasing order of abundance is

$Si > C > Sn > Pb > Ge$

If the valency shell electronic structure for an element is

$ns^{2} np^5$ , this element will belong to the group of:

0%
alkali metals
0%
inert metals
0%
noble gases
0%
halogens

Explanation

The valence shell or orbital electronic configuration of halogens(17th group elements) is

$ns^2\ np^5$ .

Hence, the correct option is

$\text{D}$

The correct statement with respect to the property of IV A group elements is:

0%
their metallic nature decreases from carbon to lead
0%
the stability of +2 oxidation state increases from carbon to lead
0%
IP value increases from carbon to lead
0%
atomic radius decreases from carbon to lead

Which of the following is more stable?

0%
$Pb$ $^{4+}$
0%
$Sn$ $^{4+}$
0%
$Ge$ $^{4+}$
0%
$Si$ $^{4+}$

Which element does not show allotropy?

0%
Pb
0%
Si
0%
C
0%
Sn

When a mixture of sand and coke is heated at 3723 K, the product formed is :

0%
Carborundum
0%
Corundum
0%
Diamond
0%
Coal

Explanation

The reaction is,

$SiO_2 + 3C \rightarrow SiC+2CO$ .

Silicon carbide is formed which is also known as carborundum.
Note: Corundum is an ore of aluminum.

Which of the following is solid at room temperature?

0%
$CO$
0%
$CO_{2}$
0%
$SiO_{2}$
0%
$OF_{2}$

Explanation

Silicon dioxide involves covalent

$Si-O$ bonds. It has strong van der waal's forces of interactions and thus exists as solids.

Bond energy is highest for :

0%
$Sn - Sn$
0%
$Ge - Ge$
0%
$C - C$
0%
$Si - Si$

Explanation

Hint: Bond energy is the amount of energy that tells how strongly two atoms are connected together.

Explanation:

For covalent molecules, the bond energy is directly proportional to the electronegativity of the atoms and inversely proportional to the bond length.

Now moving down the group, the electronegativity of an atom decreases, and the size increases, which results in a decrease in the bond energy.

Thus, the bond energy will be,

$C-C>Si-Si>Ge-Ge>Sn-Sn$

Final Answer:

Henceforth the correct answer is option $C$ .

Silica dissolves readily in:

0%
$HF$
0%
$HCl$
0%
$HBr$
0%
$HNO_{3}$

Explanation

Silica is very non-reactive in its normal form and resists the attacks by acids, metals and halogens. However, it reacts with HF and NaOH.

The reactions are respectively:

$SiO_2 + 4HF \rightarrow SiF_4 + 2H_2O$

$SiO_2 + 2NaOH \rightarrow Na_2SiO_3 + H_2O$

Hence, option A is correct.

Which element does not exhibit allotropy?

0%
$C$
0%
$Sn$
0%
$Si$
0%
$Pb$

Explanation

$Pb$ orbitals are too large to form strong single

$Pb-Pb$ bonds. So, it does not exhibit allotropy.

Which of the following is correct?

0%
$GeO_{2}$ is basic
0%
$SiO_{2}$ is acidic oxide
0%
$SnCl_{4}$ is more stable than $SnCl_{2}$
0%
$PbCl_{4}$ is more stable than $PbCl_{2}$

Explanation

Silicon dioxide has no basic properties, it is weakly acidic in nature.

$GeO_2$ is amphoteric in nature.

$SnCl_2$ is is more stable than

$SnCl_4$ due to high positive charge on it and covalent character in

$SnCl_4$ .

Due to the inert pair effect, the higher oxidation state is less stable. The stability of

$+4$ oxidation state decreases down the group. So,

$PbCl_2$ is more stable than

$PbCl_4$ .

Hence option B is correct.

Which is the anhydride of orthosilicic acid?

0%
Si
0%
SiO
0%
$SiO_{2}$
0%
$SiO_{3}$

Explanation

Orthosilicic acid is

$H_4SiO_4$ . The anhydride of this acid polymerizes to form

$SiO_2$ .

$H_4SiO_4 \xrightarrow{-2H_2O} SiO_2$

Hence, option C is correct.

Which compound is solid ?

0%
$CO_{2}$
0%
$NH_{3}$
0%
$PH_{3}$
0%
$SiO_{2}$

Explanation

$CO_2$ ,

$NH_3$ ,

$PH_3$ are all gases in their natural forms whereas silica is found as various crystallographic forms - quartz, crystobalite, tridymite etc.

Which is the amorphous form of silica?

0%
Quartz
0%
Tridymite
0%
Onyx
0%
Crystobalite

Which is not true about

$SiO_{2}$ :

0%
It is a network solid
0%
It is attacked by molten NaOH
0%
It is attacked by HF
0%
It is the basic structural unit of silicates

Explanation

Silica is attacked only by HF and NaOH and it is unreactive to most other acids, metals and halogens. However, the basic structural unit of silica is

$SiO_4^{4-}$ .

So, correct option is 'D'

Whcih one of the following is used as an acidic flux in metallurgy?

0%
$CaO$
0%
$SiO_{2}$
0%
$Na_{2}CO_{3}$
0%
$SO_{2}$

Explanation

Silica is used as acidic flux because it is almost non-reactive due to the very high bond enthalpy of

$Si-O$ bond. It resists the attack by halogens, dihydrogen and most of the acids and metals even at the elevated temperature. However,

$HF$ and

$NaOH$ react with them to form

$SiF_4$ and

$Na_2CO_3$ respectively.

When

$SiO_{2}$ is reacted with sodium carbonate, the gas liberated is :

0%
$CO$
0%
$O_{2}$
0%
$CO_{2}$
0%
$O_{3}$

Explanation

The reaction is as follows:

$SiO_2 + Na_2CO_3 \rightarrow Na_2SiO_3 + CO_2$
This reaction is an example of corrosion of glass.

When

$\alpha$ -quartz is heated to 575

$^{\circ}$ C, it changes to:

0%
onyx
0%
$\beta$ -quartz
0%
tridymite
0%
crystobalite

Explanation

$\alpha$ -quartz when heated at 575

$^{\circ}$ C to form

$\beta$ -quartz. This phenomena is called inversion.

The purest form of silica is:

0%
quartz
0%
flint
0%
sand stone
0%
jaspar

Which oxide has three dimensional strucutre ?

0%
$CO_{2}$
0%
$SO_{2}$
0%
CO
0%
$SiO_{2}$

Explanation

CO,

$CO_2$ are linearly shaped molecules whereas

$SO_2$ is a bent shaped molecule.

$SiO_2$ has a three dimensional structure as Si in

$SiO_2$ is

$sp_3$ hybridised with no lone pairs.

The final product formed when silica reacts with hydrogen fluoride is :

0%
$SiF$
0%
$H_{2}SiF_{6}$
0%
$H_{2}SiF_{4}$
0%
$H_{2}SiO_{3}$

Explanation

The final product formed when silica

$(SiO_2)$ reacts with hydrogen fluoride

$(HF)$ is

$H_2SiF_6$ .

The reactions are as follows:

$SiO_2+4HF \rightarrow SiF_4 + 2H_2O$

$3SiF_4 + 4H_2O \rightarrow 2H_2SiF_6 + H_4SiO_4$

The number of Oxygen atoms bonded to each
silicon atom in silica crystal is :

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

Borax is a:

0%
tetra hydrate
0%
hepta hydrate
0%
deca hydrate
0%
penta hydrate

Explanation

Borax actually contains 10 molecules of water of crystallisation.

The formula of Borax is

$Na_2B_4O_7.10H_2O$ .

Option C is correct.

The structure of silica is :

0%
Layer lattice
0%
Tetrahedral
0%
Trigonal
0%
Linear

Explanation

Silica exists as a polymeric solid, in which each Silicon atom is bonded to 4 oxygen atoms and each oxygen atom is bonded to 2 silicon atoms. Thus, in this structure, each silica molecule has a tetrahedral structure, with silicon atom having

$sp^3$ hybridisation.

Which one of the following is true with respect to

$SiO_{2}$ ?

0%
Linear, acidic
0%
Linear, basic
0%
Tetrahedral, acidic
0%
Angular, basic

Explanation

$SiO_2$ is acidic in nature and is used as an acidic flux in metallurgy. Silicon in

$SiO_2$ is

$sp^3$ hybridised which gives it a tetrahedral structure.

Hence, option C is the correct answer.

Which oxides has three dimensional structure ?

0%
CO
0%
$CO_{2}$
0%
$SiO_{2}$
0%
$SO_{2}$

Explanation

$CO$ ,

$CO_2$ are linear molecules whereas

$SO_2$ is a bent shaped molecule. However,

$SiO_2$ is 3-d shaped due to

$sp_3$ hybridisation of silicon.

Organosilicon polymers containing which type of linkages:

0%
Si-S-Si
0%
Si-O-Si
0%
Si-N-Si
0%
Si-C-Si

Explanation

Organosilicon compounds have general formula

$[R_{2} SiO]_{n}$ .

Hybridisation of silicon atom in silica is :

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

Explanation

Silicon in silica forms 4 sigma bonds thus its hybridisation is

$sp_3$ .

Which is not a true dioxide?

0%
$CO_{2}$
0%
$SO_{2}$
0%
$MnO_{2}$
0%
$SiO_{2}$

Explanation

Silicon dioxide is a three dimensional network solid in which each Si-atom is covalently bonded in tetrahedral manner with four oxygen atom while in

$CO_2$ ,

$SO_2$ and

$MnO_2$ . C, S and Mn atoms are bonded to oxygen atom by either

$\pi$ -bond or coordinate covalent bonds.

$SiO_2 + 4HF \rightarrow SiF_4 + 2H_2O$

The structure of crystalline silica is similar to that
of:

0%
Diamond
0%
Graphite
0%
Silicates
0%
Silicic acid

The major product formed when alkyl chloride when passed over silicon at 300

$^{\circ}$ C in the presence of Cu catalyst?

0%
$R-S-Cl_{2}$
0%
$R_{2}-SiCl_{2}$
0%
$R_{2}-SiCl$
0%
$R_{4}-Si$

Explanation

$R_{2} - SiCl_{2}$ (Major product)

$R_{3} - SiCl, R - SiCl_{3}$ (Minor products)

Which of the following is/are not correct?

0%
$SiO_{2}$ is used as acid flux.
0%
The distance between the layers in graphite is $3.35\times10^{-8}$ cm.
0%
$SiO_{2}$ reacts with $Na_{2}CO_{3}$ and liberates CO.
0%
The hybridization of C in graphite is $Sp^{2}$ .

Explanation

$CO_2$ is released when

$SiO_2$ reacts with

$Na_2CO_3$ .

$SiO_2 + Na_2CO_3 \rightarrow Na_2SiO_3 + CO_2$

Silicones have the general formula :

0%
$SiO_{4}^{4-}$
0%
$Si_{2}O_{7}^{6-}$
0%
$(R_{2}SiO)_{n}$
0%
$(SiO_{3})_{n}^{2-}$

Explanation

Organosilicon compounds are also called silicones which have general formula

$[R_{2} SiO]_{n}$ .

The example of cyclic silicate is.

0%
$Be_{3} Al_{2}[Si_{6}O_{18}]$
0%
$Al_{2}(OH)_{4}Si_{2}O_{5}$
0%
$(Na_{g}[Al_{6}Si_{6}O_{24}]S_{2})$
0%
$Zn_{2}(SiO_{4})$

Explanation

Cyclic silicates have general formula:

$[SiO_{3}]_{n} ^{2n-}$

$SiO_{2}+A\rightarrow X+Y$ In this reaction 'Y' is one of the global warming gases. 'A' is the water soluble alkali metal carbonate. Whose molecular weight isThe common name of 'X' is :

0%
Washing soda
0%
Baking soda
0%
Flint glass
0%
Water glass

Explanation

$SiO_2 + Na_2CO_3 \rightarrow Na_2SiO_3 + CO_2$
A is

$Na_2CO_3$ having atomic weight 106, Y is

$CO_2$ and X is

$Na_2SiO_3$ which is also called water glass.

CBSE Questions for Class 11 Engineering Chemistry Some P-Block Elements Quiz 2 - 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 2 - MCQExams.com

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Practice Class 11 Engineering Chemistry Quiz Questions and Answers

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