MCQ Questions for Class 12 Engineering Chemistry The P-Block Elements Quiz 13

Which of the following species do not exist?

0%
$XeF_3$
0%
$XeF_4$
0%
$XeF_5$
0%
$XeF_6$

Explanation

$XeF_3$ and

$XeF_5$ does not exist. These contain a total of odd number of electrons, where bonding or hybridization is not possible. However,

$XeF_2$ ,

$XeF_4$ and

$XeF_6$ do exist.

If atomic number of inert gas is

$Z$ , then ionic bond is formed between:

0%
$(Z - 1)$ and $(Z + 1)$
0%
$(Z - 2)$ and $(Z + 2)$
0%
both (a) and (b)
0%
none of these

Explanation

If Z is the atomic number of the inert gas, then

$\left.\begin{matrix}(z\,-\,1) &\Rightarrow &halogens (z\,+\,1)\,=\,alkali\,\, metals \\ (z\,-\,2)&\Rightarrow & oxygen family; (z\,+\,2)\,=\,alkaline\,\,earth\,\,metals\end{matrix}\right\}From \,\,ionic\,\, compound$

The following acids have been arranged in the order of decreasing acid strength. Identify the correct order: ClOH (I), BrOH (II), IOH (III).

0%
$I> II > III$
0%
$II>I>III$
0%
$III>II>I$
0%
$I>III>II$

Explanation

For the same oxidation state, when the electronegativity of the halogen increases, the strength of the oxyacid increases.

$HOCI > HOBr > HOI$

Hence option A is correct.

Which one of the following oxy acid of fluorine exists ?

0%
$HOF$
0%
$HFO_{3}$
0%
$HFO_{4}$
0%
$HFO_{2}$

The statement, which prompted Neil Bartlett to prepare the first noble gas compound was :

0%
$Xe-F$ bond has high bond energy
0%
$F_{2}$ has exceptionally low bond energy
0%
$PtF_{6}$ is a strong oxidant
0%
$O_{2}$ molecule and Xe atom have very similar ionization energies.

Explanation

Bartlett's main specialty was the chemistry of fluorine and of compounds containing fluorine. In 1962, Bartlett prepared the first noble gas compound, xenon hexafluoroplatinate. This contradicted established models of the nature of valency, as it was believed that all noble gases were entirely inert to chemical combination. He subsequently produced and reproduced several other fluorides of xenon.
The statement, which prompted Neil Bartlett to prepare the first noble gas compound was

$O_{2}$ molecule and Xe atom have very similar ionization energies.

Write True or false:

Phosphorous occurs as

PIts atomicity is 5

P 'its atomicity is 5.

0%
True
0%
False

Explanation

Atomicity of phosphorus is 5 and its molecular formula is

$P_s$

Hence option-A is correct.

The following acids have been arranged in the order of decreasing acid strength. Identify the correct order-
ClOH(I) BrOH(II) IOH(III)

0%
I > II > III
0%
II > I > III
0%
III > II > I
0%
I > III > II

At high temperature, nitrogen combines with

$CaC_2$ to give___________.

0%
calcium cyanide
0%
calcium cyanamide
0%
calcium carbonate
0%
calcium nitride

Explanation

Calcium carbide is used in the production of calcium cyanamide by means of reacting it with nitrogen in a high temperature.

${ CaC }_{ 2 }+{ N }_{ 2 }\rightarrow { CaCN }_{ 2 }+C$

Haber's process is a/an:

0%
endothermic process
0%
exothermic process
0%
spontaneous with no heat liberation
0%
None

Explanation

Hint:

The process used for manufacturing ammonia from nitrogen and hydrogen is termed Haber’s process.

Explanation:

Part 1:

The chemical reaction involved in this process is $N_2\left ( g \right )+3H_2\left ( g \right )\rightleftharpoons 2NH_3\left ( g \right )+\Delta H$

Here, $\Delta H=-92.4 \dfrac{kJ}{mol}$

Part 2:

The important conditions necessary for this process are

The volume of gasses of nitrogen and hydrogen should maintain $1:3$ ratio.

The temperature and pressure should be above $723K$ and $200 atm$ respectively.

Iron is used as a catalyst and molybdenum as a promoter.

Final answer:

The negative sign of enthalpy in the chemical reaction signifies that the heat is released.

Therefore the correct answer is option B i.e., Haber’s process is an exothermic process.

In the commercial preparation of dinitrogen by the liquefaction and fractional distillation,dinitrogen is obtained in:

0%
liquid form
0%
gaseous form
0%
mixture of liquid and gases
0%
none

Molecules of noble gases do not possess vibrational energy because, noble gases:

0%
are monoatomic
0%
are chemically inert
0%
have completely filled shells
0%
are diatomic

Compound formed on reaction of nitrogen with oxygen at very high temperature is:

0%
$NO_2$
0%
$N_2O_4$
0%
$NO$
0%
$N_2O_3$

Explanation

$N_2+O_2 \rightarrow NO$

The reaction occurs at temperature greater than 2000 C.

The colour discharge tubes for advertisements mainly contains:

0%
argon
0%
neon
0%
helium
0%
xenon

Which mineral was used in isolation of radium?

0%
lime stone
0%
pitch blende
0%
rectile
0%
haematite

In gaseous discharge tube,the colour of light emitted by helium is:

0%
yellow
0%
red
0%
blue
0%
green

Which of the following noble gas is least polarizable?

0%
xenon
0%
argon
0%
neon
0%
helium

Which is most soluble in water at

$293K$ ?

0%
Helium
0%
Neon
0%
Xenon
0%
Krypton

Explanation

Noble gases are sparingly soluble in water. The solubility of noble gases in water increases as the size of noble gases increases. Noble gas is soluble in water due to dipole induced dipole interaction(forces). As the size of noble gas increases, it can be polarized easily by water molecules and distort the electron cloud. Due to this reason the solubility of inert gases in water increases as the size increases from $He$ to $Rn$ .

So in the given noble gases, Krypton is most soluble in water at $293\ K$ .

Hence option $D$ is correct.

Which of the following has lowest boiling point?

0%
Helium
0%
Neon
0%
Xenon
0%
Argon

The force acting between noble gas atoms are:

0%
van der Waals force
0%
ion-dipole force
0%
London dispersion force
0%
magnetic force

Inert gases such as helium behave like ideal gases over a wide range of temperature. However they condense into the solid state at very low temperature there is a:

0%
Weak attractive forces between the atoms
0%
Weak repulsive force between the atoms
0%
Strong attractive force between the atoms
0%
Strong repulsive force between the atome

Which is called stranger gas?

0%
$Kr$
0%
$Xe$
0%
$He$
0%
$Ne$

Explanation

$Xe$ is known as stranger gas because it belongs to the noble gas category but it reacts with oxygen and fluorine. So, stranger gas name is given to it.

So, the correct answer is option

$B$ .

Which of the following is not correct for noble gas?

0%
Argon is used in electric bulb.
0%
Krypton is obtained during radioactive disintegration.
0%
Half life of radon is 3.8 days
0%
Helium is used to produce low temperature.

Explanation

Traces of krypton are found in various minerals, the most important source of Krypton is Earth's atmosphere. Air is also the source for the other noble gases, with the exception of helium which obtained from natural gas and radon which is obtained as a byproduct of the decay of radioactive elements

So Krypton is not obtained during radioactive disintegration. It is radon formed during radioactive disintegration.

Hence option $B$ is correct.

With which of the following halogen, germanium does not form a dihalide?

0%
Fluorine
0%
Chlorine
0%
Bromine
0%
Iodine

The electron affinity values for the halogens show the following trends

0%
$F< Cl> Br> I$
0%
$F< Cl< Br< I$
0%
$F> Cl> Br> I$
0%
$F< Cl> Br< I$

Less ionic compound among the following

0%
NaF
0%
KCl
0%
KF
0%
NaCl

Which of the following is NOT changed of Xe in given reaction?

$2XeO{F}_{4} + Si{O}_{2} \rightarrow 2Xe{O}_{2}{F}_{2}+ Si{F}_{4}$

0%
Hybridisation of Xe
0%
Number of d-orbital(s) is hybridisation
0%
Number of $O-Xe-F$ bond angle
0%
Covalency of Xe

Explanation

$2XeOF_4+SiO_2\longrightarrow 2XeO_2F_2+SiF_4$

Covalency of

$XeOF_4$ is 6(refer to image 01)

Covalency of

$XeO_2F_2$ is 6(refer to image 02)

So, covalency of

$Xe$ is 6 which donot change.

1059054_1171984_ans_5ed9e37060d84516acc060c8ae7e3a34.png

Which of the following has

$p\pi -d\pi$ bonding?

0%
${ NO }_{ 3 }^{ - }$
0%
${ CO }_{ 3 }^{ - }$
0%
${ BO }_{ 3 }^{ - }$
0%
${ SO }_{ 3 }^{ - }$

Explanation

$p\pi-d\pi$ bonding includes d-orbitals,if you observe the options only S belongs to

$3^{rd}$ period and has d-orbitals(though unoccupied in ground state).

Other options

$C$ and

$N$ belongs to

$2^{nd}$ period while B belongs to

$1^{st}$ period and doesn't have d-orbitals.

Acidic nature of amino group is shown by the reaction :-

0%
$R{ - }{ N }{ H }_{ 2\quad }+NOCL\longrightarrow RCI+{ N }_{ 2 }+{ H }_{ 2 }O$
0%
$2RN{ H }_{ 2 }+2Na\longrightarrow 2RNH.Na+{ N }_{ 2 }$
0%
$R.C{ H }_{ 2 }N{ H }_{ 2 }+HN{ O }_{ 2 }+{ N }_{ 2 }+{ H }_{ 2 }{ O }$
0%
$R.N{ H }_{ 2 }+HCL\longrightarrow RN{ H }_{ 3 }CL$

${ I }_{ 2 }C{ l }_{ 6}$ is formed by the following reaction:

$2IC{ l }_{ 3}\rightleftharpoons {I }_{2 }C{l }_{ 6 }$

Based on the structure of

${I }_{2 }C{l }_{ 6 }$ , find the number of atoms lying in one plane.

0%
4
0%
6
0%
8
0%
10

Explanation

The maximum number of atoms in a plane in

$I_2Cl_6$ is 8 and has 3c- 4e bonds in the structure.

Hence, the correct option is C.

2018931_1150926_ans_c530b7c7df954ce98a887c94c25df0e3.jpeg

In NaOX , X cannot be:

0%
${ F }_{ 2 }$
0%
${ Cl }_{ 2 }$
0%
${ Br }_{ 2 }$
0%
$I_{ 2 }$

Explanation

The Sodium hypoiodite,

$NaOI$ has never been isolated, but is formed in dilute aqueous solution by the interaction of sodium hydroxide and iodine, and to a small extent by the electrolysis of an alkaline solution of sodium iodide. The

$\text{substance is extremely unstable, reduction to iodide and oxidation to iodate taking place simultaneously.}$

Thus, Option D is the answer.

Select the correct statement (s)

0%
HCI and HF do not from free radical easily due to larger bond-energy
0%
HI with a minimum bond energy is every reactive and instead from ${{\text{I}}_{\text{2}}}\,\,\,$
0%
Both (a) and (b)
0%
None of the above

The oxide of nitrogen responsible for acid rain is:

0%
nitrous oxide
0%
nitric oxide
0%
nitrogen dioxide
0%
all of these

The most powerful oxidant among the following is:

0%
$HOCl$
0%
$HClO_2$
0%
$HClO_3$
0%
$HClO_4$

Explanation

(B)

$HClO_2$

Standard reduction potential is

$1.6$ V and is the highest strongest oxidant among all these.

Which is the best nucleophile in polar solvent?

0%
${ F }^{ - }$
0%
${ Cl }^{ - }$
0%
$Br^{ - }$
0%
$I^{ - }$

Explanation

The small sized ion has greater charge density. Due to high charge density in polar solvent, they get easily hydrated. So

$I^{\circleddash}$ has greater size. So, it will be best nucleophile in polar solvent.

Halogens are placed in which group of elements in modern periodic table.

0%
17
0%
2
0%
4
0%
6

The pair with minimum difference in electronegativity is :-

0%
F,Cl
0%
C,H
0%
P,H
0%
Na,Cs

Number of sigma bonds in

$P_{4}O_{10}$ is :

0%
$6$
0%
$7$
0%
$17$
0%
$16$

In Haber process

$30L$ of Dihydrogen and

$30L$ of dinitrogen were taken for reaction which yielded only

$50\%$ of the expected product . what will be the composition of gaseous mixture under the aforesaid condition in the end?

0%
$20L$ ammonia $10L$ nitrogen , $30L$ hydrogen
0%
$20L$ ammonia , $125L$ nitrogen , $25L$ ydrogen
0%
$20L$ ammonia , $20L$ nitrogen , $20L$ hydrogen
0%
$10L$ ammonia , $25L$ nitrogen , $15L$ hydrogen

Explanation

solution:

$N_2+3H_2 \rightleftharpoons 2NH_3$

30 30 0

30-x 30-x 2x

$2x = 10$

x = 5;

$N_2 = 30 - 5 = 25 L$

$H_2 = 30 - 3X 5 = 15 L$

30 L of H_2 will react with 10 L of N_2 to produce 20 L of

$NH_3$ (Here

$H_2$ is the limiting reactant). As the yield is only 50%, 15 L of

$H_2$ will react with 5 L of

$N_2$ to produce 10 L of

$NH_3$

Reaction mixture will contain,

15 L of

$H_2$ (30L-15L), and 10 L of

$NH_3$

hence the correct opt: D

Which of the following metal on burining in mosist air does not give smell of ammonia?

0%
$Mg$
0%
$Ca$
0%
$K$
0%
$Li$

Indicate which of the following statement is true or false.
The reaction between hydrogen and nitrogen to form ammonia is reversible.

0%
True
0%
False

Explanation

When hydrogen gas combines with nitrogen to form Ammonia the following chemical reaction will take place. Our equilibrium reaction will be

$N_2$ (g) + 3

$H_2$ (g) ⇔ 2

$NH_3$ (g) + Heat

In this case, Hydrogen and nitrogen react together to form ammonia.

You can find the concentration/ mass of product (NH3) formed at equilibrium if you know the equilibrium constant (K) of the reaction.

The rate of reaction (forward or backward) changes with the change in pressure and temperature.

$P_4$ is a stable from of phosphorus. The percentage of p-character in the orbital forming (P - P) bonds in

$P_4$ is

0%
25
0%
33
0%
50
0%
75

Which of the following is paramagnetic in nature?

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

The compound that cannot be formed by Xenon is

0%
$XeO_3$
0%
$XeF_4$
0%
$XeCl_4$
0%
$XeO_2F_2$

Most reactive nobel gas is :

0%
$Ar$
0%
$Xe$
0%
$He$
0%
$Ne$

Explanation

As size increases, I.E. decreases reactivity of noble gas increases so

$Xe$ is most reactive.

Lowest oxidation state of phosphorous is in:

0%
${ H_{ 3 } }{ PO }_{ 2 }$
0%
${ H_{ 3 } }{ PO }_{ 4 }$
0%
${ H_{ 4 } }{ P_{ 2 }O }_{ 7 }$
0%
${ H_{ 3 } }{ PO }_{ 3 }$

Explanation

oxidation state of oxygen ;-

$-2$

oxidation state of hydrogen ;-

$1$

$H_3PO_2$ :-

$1*3 + x +(-2)*2=0$

$x=1$

$H_3PO_4$ :-

$1*3 + x +(-2)*4=0$

$x=5$

$H_4P_2O_7$ :-

$1*4 + 2x +(-2)*7=0$

$x=5$

$H_3PO_3$ :-

$1*3 + x +(-2)*3=0$

$x=3$

As we can see from the result:-

$H_3PO_3$ has the lowest oxidation state.

$N_{2}H_{4}+2H_{2}O_{4}\rightarrow 4H_{2}O_2$ .

This equation suggests the use of

$H_{2}O_{2}$ as :

0%
Bleaching agent
0%
Antisepics
0%
Restoring colour of old paintings
0%
Rocket Propellant

Of the following species, one which is non-existent :

0%
$Xe{F_6}$
0%
$Xe{F_5}\;$
0%
$Xe{F_4}$
0%
$Xe{F_2}$

Explanation

Xe forms only three flourides

$XeF_2,XeF_4,XeF_6$

so,

$XeF_5$ is non-existent.

1327477_1376314_ans_739f4c3436bb443980a8708658ba9428.jpg

Charge on a pseudo halide ion is:

0%
$-1$
0%
$-2$
0%
$-3$
0%
$(1)$ & $(2)$

The electronic configuration of halogen is :

0%
$ns^{2}np^{6}$
0%
$ns^{2}np^{3}$
0%
$ns^{2}np^{5}$
0%
$ns^{2}$

Explanation

Halogen belongs to chlorine family.

So electronic configuration of halogen is

$ns^{2} np^{5}$

Two major requirements for preparation of ammonia are

0%
Low temperature and high pressure
0%
Low temperature and present pressure
0%
High temperature and low pressure
0%
High temperature and high pressure

CBSE Questions for Class 12 Engineering Chemistry The P-Block Elements Quiz 13 - MCQExams.com

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