MCQ Questions for Class 11 Medical Chemistry Hydrogen Quiz 7

Which of the following will produce hydrogen on decomposition by metals like

$Na,K,Ca$ ?

0%
Boiling water
0%
Steam
0%
Cold water
0%
All of the above

Explanation

$Na,K,Ca$ lie at the top of the electrochemical series and are very easily oxidised which makes it a very strong reducing agent.As a result,it can reduce all the three,i.e,boiling water,steam,cold water.

Dihydrogen can be prepared on a commercial scale by different methods. In its preparation by the action of steam on hydrocarbons, a mixture of

$CO$ and

$H_2$ gas is formed. It is known as ___________.

0%
water gas
0%
syngas
0%
producer gas
0%
industrial gas

Explanation

Steam reforming is a method for producing hydrogen, carbon monoxide, or other useful products from hydrocarbon fuels such as natural gas. This is achieved in a processing device called a reformer which reacts steam at high temperature with the fossil fuel.

Steam reforming of natural gas - sometimes referred to as steam methane reforming (SMR) - is the most common method of producing commercial bulk hydrogen. Hydrogen is used in the industrial synthesis of ammonia and other chemicals. At high temperatures (700 – 1100 °C) and in the presence of a metal-based catalyst (nickel), steam reacts with methane to yield carbon monoxide and hydrogen.

$C{ H }_{ 4 }+{ H }_{ 2 }O\leftrightharpoons CO+3{ H }_{ 2 }$

Which one of the following is not an industrial method of preparation of hydrogen?

0%
Electrolysis of brine
0%
Electrolysis of acidified water
0%
Wurtz reaction
0%
Boschs process or Lanes process

Explanation

The Wurtz reaction, named after Charles-Adolphe Wurtz, is a coupling reaction in organic chemistry, organometallic chemistry and recently inorganic main group polymers, whereby two alkyl halides are reacted with sodium to form a new alkane:

$2R–X+2{ Na }^{ + }\longrightarrow R–R+2{ Na }^{ + }+{ X }^{ - }$

The carbon dioxide produced in water gas shift reaction is removed by scrubbing with :

0%
sodium hydroxide solution
0%
sodium arsenite solution
0%
sodium chloride solution
0%
water

Which of the following will be decomposed into hydrogen by metals like

$Fe,Sn,Ni$ ?

0%
Cold water
0%
Boiling water
0%
Steam
0%
All of these

Explanation

$Fe,Sn,Ni$ are not easily oxidised so,it is a poor reducing agent and can not reduce cold and boiling water.It can just reduce steam.Steam is the easiest to reduce.

The compound that gives

$H_2O_2$ on treatment with dilute

$H_2SO_4$ is:

0%
$PbO_2$
0%
$BaO_2.8H_2O+O_2$
0%
$MnO_2$
0%
$TiO_2$

Electrolysis of acidified water using platinum electrodes gives ________.

0%
oxygen and hydrogen peroxide
0%
hydrogen and oxygen
0%
hydrogen peroxide
0%
hydrogen and hydrogen peroxide

On electrolysis of NaH, hydrogen is liberated at:

0%
anode
0%
cathode
0%
inert electrode
0%
none of these

Explanation

Sodium hydride is an ionic compound which decomposes below its melting point, so it would be extremely difficult to obtain molten sodium hydride in the first place.

However, if you were able to somehow melt some sodium hydride, its electrolysis would produce liquid sodium metal at the cathode and hydrogen gas at the anode;-

Cathode reaction:

$2{ Na }^{ + }+2{ e }^{ - }\longrightarrow 2{ Na }_{ (l) }$

Anode reaction:

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

The overall reaction is:

$2Na{ H }_{ (l) }\longrightarrow 2{ Na }_{ (l) }+{ H }_{ 2(g) }$

Which of the following reactions increases production of dihydrogen from synthesis gas?

0%
$CH_4(g) +\ H_2O(g) \xrightarrow[Ni]{1270 K} CO(g) +\ 3H_2(g)$
0%
$C(s) +\ H_2O(g) \xrightarrow {1270K} CO(g) +\ H_2(g)$
0%
$CO(g) + H_2O(g) \xrightarrow[673 K]{Catalyst}{C{O_2}}(g) + H_2(g)$
0%
$C_2H_8(g) +\ 2H_2O(g) \xrightarrow[Ni]{1270 K} 2CO(g) +\ 5H_2(g)$

Explanation

Hint: The water gas shift reaction is the reaction of carbon monoxide and water vapor to form carbon dioxide and hydrogen.

Explanation:

The production of dihydrogen is increased by reacting carbon monoxide of synthesis gas mixture with the steam.
The reaction is catalyzed by iron chromate.
Reaction is:

Hence, the correct answer is option $(C).$

Zinc react with aqueous sodium hydroxide to form dihydrogen and __________.

0%
zinc oxide
0%
sodium zincate
0%
zinc hydroxide
0%
sodium precipitate

Explanation

Zinc will react with Sodium Hydroxide to from Sodium Zincate. In this reaction Zinc will not displace sodium from sodium hydroxide, but will displace Hydrogen as shown below:

$2NaOH+Zn\longrightarrow { Na }_{ 2 }Zn{ O }_{ 2 }+{ H }_{ 2 }$

This reaction is accompanied by evolution of Hydrogen gas.

High purity (>99.95%) dihydrogen is obtained by electrolyzing warm aqueous ________ hydroxide solution between nickel electrodes.

0%
magnesium
0%
barium
0%
calcium
0%
sodium

In the laboratory preparation of Dihydrogen,which of the following species is oxidised?

0%
$Zn$
0%
$H_2$
0%
Both A and B
0%
None

Explanation

The chemical reaction for laboratory preparation of water is shown below:

$Zn + H_2SO_4 \longrightarrow ZnSO_4 + H_2$ ,or

$Zn + HCl \longrightarrow ZnCl_2 + H_2$

This shows that in either case,

$Zn$ is being oxidised.

Which is the correct combination of products collected over anode and cathode respectively in order to prepare hydrogen by electrolysis of water?

0%
$O_2,H_2$
0%
$H_2,O_2$
0%
$Na,O_2$
0%
$O_2,Na$

Explanation

Electrolysis of water is the decomposition of water

$(H_2O)$ into oxygen

$(O_2)$ and hydrogen gas

$(H_2)$ due to an electric current being passed through the water.

$O_2$ is collected at anode and

$H_2$ is collected at cathode.
Option A is correct.

In the laboratory preparation of dihydrogen, which of the following species is reduced?

0%
$Zn^+$
0%
$H^+$
0%
Both $A$ and $B$
0%
None of the above

Explanation

The chemical reaction for laboratory preparation of water is shown below:

$Zn + H_2SO_4 \longrightarrow ZnSO_4 + H_2$ ,or

$Zn + HCl \longrightarrow ZnCl_2 + H_2$

This shows that in either case,

$H^+$ is being reduced to

$H_2$ .

Which is NOT a commercial method for preparation of Dihydrogen?

0%
Lane's Process
0%
Thermal cracking of natural gas
0%
Reacting metals with dilute mineral acids
0%
Syngas-Bosch Process

A person was using water supplied by municipality. Due to shortage of water, he started using underground water. He felt laxative effect. Its cause due to high concentration of:

0%
$CO_2$
0%
$SO^{2-}_4$
0%
$CO^{2-}_3$
0%
$S^{2-}$

Explanation

The laxative effect is observed only when the sulphates present in water have concentration greater than

$500$ ppm. Otherwise at moderate levels, it is harmless.

The oxide that gives

$H_2O_2$ on treatment with dilute

$H_2SO_4$ is:

0%
$PbO_2$
0%
$BaO_2. 8H_2O$
0%
$MnO_2$
0%
$TiO_2$

Explanation

The oxide that gives

$H_2O_2$ on treatment with dilute

$H_2SO_4$ is

$BaO_2. 8H_2O$ .

$BaO_2. 8H_2O({s}) + H_2SO_4({aq})\rightarrow BaSO_4({s}) + H_2O_2({aq}) + 8H_2O{(l)}$

In the Lane's process for the manufacture of hydrogen the reagents used in oxidation-reduction process are respectively:

0%
$Fe/H_2O$ and water gas
0%
$Fe_3O_4\ and\ H_2$
0%
$O_2\ and\ H_2$
0%
$Fe/H_2O$ and $Fe_3O_4$

Explanation

The Lane's process involves following reactions:-

$3Fe+4H_2O\longrightarrow Fe_3O_4+4H_2$

$Fe_3O_4+CO\longrightarrow 3Fe+CO_2$

water

gas

Net reaction :-

$CO+H_2O\longrightarrow CO_2+H_2$

The iron and steam are used to produce

$Fe_3O_4$ &

$H_2$ which then reacts with water gas to liberate

$CO_2$ and produce fresh iron which again reacts with steam & the process goes on. It is called Lane's process for manufacturing of hydrogen gas.

Thus the answer is option (A)

$Fe/H_2O$ and water gas.

Which of the following method produces

$H_2$ as By-product?

0%
Petroleum Cracking in plants
0%
In Electrolysis of Brine
0%
Microbial Biomass conversion
0%
All the above

Explanation

Petroleum Cracking in plants,Microbial Biomass conversion and Electrolysis of Brine,all the three processes produces

$H_2$ as by-product.

Which of the one is correct about Hydrogen?

0%
resembles in IA since it forms monovalent cation $H^+$ .
0%
resembles in VIIA (halogen family) since it forms monovalent anion $H^-$ .
0%
resembles in IVA(carbon family) since both have a half filled shell of electron.
0%
all of the above

Which of the following cause alkalinity as well as hardness in natural water?

0%
$CaCO_3$
0%
$Ca(HCO_3)_2$
0%
$MgCO_3$
0%
All of the above

Temporary hardness is caused due to the presence of:

0%
magnesium sulphate
0%
magnesium chloride
0%
calcium sulphate
0%
magnesium carbonate

Hydrogen can be produced by:

0%
electrolysis of water
0%
distillation of air
0%
steam methane reforming process
0%
evaporation of water

Explanation

On electrolysis of water we have

at cathode:

$2H^+ + 2e^- \rightarrow H_2(g)$

steam methane reforming is the process of forming hydrogen and carbon monoxide, together known as syngas.

The source of Arsenic in water is:

0%
industrial waste
0%
fertilizers
0%
phosphate rocks
0%
all of the above

Which of the following are the essential things required for rusting?

0%
oxygen
0%
water
0%
both
0%
none of the above

Which catalyst is used for the industrial production of hydrogen?

0%
Iron
0%
Nickel
0%
Vanadium pentaxide
0%
Palladium

Which of the following is true regarding pure water?

0%
Can dissolve anything
0%
Higher density than egg
0%
Lesser dense than ice
0%
None of these

Which of the following is an example of condensation?

0%
Dew forms in the morning
0%
The mirror in the bathroom during a shower getting foggy
0%
Water droplets formation on cold water bottle
0%
Cooling of water in refrigerator

Permanent hardness is caused due to:

0%
magnesium bicarbonate
0%
magnesium carbonate
0%
magnesium sulphate
0%
all of the above

Deuterium occurs in trace amounts naturally as deuterium gas represented as:

0%
$D_2$
0%
$^2H_2$
0%
both A and B
0%
$^2D$

Explanation

Deuterium occurs in trace amounts naturally as deuterium gas written as

$D_2$ as well as

$^2H_2$ .

Pressure cooker reduces cooking time because:

0%
the heat is more evenly distributed inside the cooker
0%
a large flame is used
0%
boiling point of water is elevated
0%
whole matter is converted into steam

Explanation

Because under pressure, the heat builds faster and maintains temperature better, so cooking time is reduced. ... The increased pressure inside the cooker increases the boiling point of water above

$100 ^0C$ so more cooking is done before the water actually starts to boil. So ultimately food is cooked faster.

Hydrogen is produced by the reaction:

0%
$Na_2O_2+2HCl$
0%
$Mg+H_2O$
0%
$BaO_2+HCl$
0%
$H_2S_4O_8+H_2O$

Explanation

$Mg+H_2O\overset{\Delta }{\rightarrow}Mg(OH)_2+H_2$

It produces magnesium hydroxide and hydrogen gas.

Compounds which evaporate easily and easily gives smell are:

0%
ionic compounds
0%
metallic compounds
0%
covalent compounds
0%
none of these

Hydrogen is mainly found in the combined state like in water and not the free state.

0%
True
0%
False

Explanation

The earths crust contains nearly 1% hydrogen by weight. In free state(

$H_2$ ), it occurs only in traces in the atmosphere. It is mainly found in the combined state and not the free state. Important sources are water, acids, organic matter etc.

Water has maximum density at

0%
Room temperature
0%
${4}^{o}C$
0%
${0}^{o}C$
0%
$-{4}^{o}C$

Explanation

When Water is in its Solid form (Ice) below

$0^0 C$ , it is forced into a regular Cage like Structure with small voids due to which the Volume of Ice is larger.

$4^0 C$ , the cage-like structure of ice starts to break and the molecules can slide along each other, closing the empty voids due to which momentarily the volume of water decreases. Due to decrease in volume, density increases because density is inversely proportional to volume.

As temperature rises to over

$4^0 C$ , the extra space needed by increased motion of water molecules starts being larger than the space gained due to structural changes and the molecules start to move away from each other due to which the volume again increases and density decreases.

Thus, Density maximum is reached at

$4^0C$ .

Pure water is natural because :

0%
pH = 7
0%
litmus has no effect
0%
it is free from dissolved salts
0%
pH=0

Explanation

Pure water means water that has nothing in it except

$H_2O$ (hydrogen and oxygen).

Water from various sources contains dissolved gases, minerals, organic substances.

So water is natural which is free from dissolved salts.

Hence the correct option is C.

Compound soluble in water which does not impede oxygen transportation is?

0%
$SO_2$
0%
$SO_3$
0%
CO
0%
NO

Explanation

Oxygen transport is reduced in acidic conditions.

$SO_2$ makes the blood less acidic as compared to

$SO_3$ . CO and NO combine with haemoglobin and reduce its oxygen carrying capacity.

Hydrogen peroxide molecules are:

0%
monoatomic and form $X^{2-}_2$ ions
0%
diatomic and form $X^-$ ions
0%
diatomic and form $H{ O }^-_2$ ions
0%
monoatomic and form $X^-$ ions

Explanation

$H_2O_2$ is a monoatomic molecule as it contains only one atom. It can be simply represented as

$HO-OH$ . It form

$(OH)_2^{2-}$ ions on breakage. That is, it forms

$X_2^{2-}$ ions.

$HO-OH\rightleftharpoons {{(OH)}_2^{-2}}$

The volume strength of

$1$ molar solution of

${ H }_{ 2 }{ O }_{ 2 }$ is:

0%
$11.2$
0%
$22.4$
0%
$5.6$
0%
$56$

Explanation

$1$ molar

${ H }_{ 2 }{ O }_{ 2 }$ solution means

$1$ mole (or

$34g$ ) of (

${ H }_{ 2 }{ O }_{ 2 }$ ) present in

${10}^{3}\,mL$ solution.

$\therefore$

$68g$

${ H }_{ 2 }{ O }_{ 2 }$ gives

$=22400\,mL$ of

${O}_{2}$

$\therefore$

$68g$

${ H }_{ 2 }{ O }_{ 2 }$ gives

$=\cfrac { 22400 \,mL\times 34 }{ 68 } =11200\,mL$ of

${O}_{2}$

Volume strength

$=\cfrac { 11200 }{ { 10 }^{ 3 } } =11.2\ V$

Gas produced after introduction of

$H_{2}$ in the mixture?

0%
$H_{2}O$
0%
$CH_{4}$
0%
$CO_{2}$
0%
$NH_{3}$

Explanation

Given

Volume of

$N_{2}$ , Alkane,

$O_{2}$ is 10 ml

Solution

Reaction of

$N_{2}$ ,

$C_{n}H_{2n+2}$ ,

$O_{2}$ gives

$CO_{2}$

$CO_{2}$ is absorbed by KOH

Volume contracted = 2ml

Hence Volume of

$CO_{2}$ = 2ml

Now in tube only

$N_{2}$ and Alkane is left

When

$N_{2}$ is reacted with excess of

$H_{2}$ it forms

$NH_{3}$ .

The correct option is D

Products formed are:

$2NaBH_4+I_2 \overset{Polyether}{\rightarrow}$ ?

0%
$HI, Nal$ and $H_2$
0%
$B_2H_6, Nal$ and $HI$
0%
$B_2H_6, Nal$ and $H_2$
0%
$H_3BO_3+H_2$

Explanation

$NaBH_4+I_2\quad \underrightarrow {Polyether}\quad BH_3+HI+NaI$

$\downarrow$

$NaBH_4$

$B_2H_6+2NaI+H_2$

Therefore, sodium borohydride reacts with iodine in presence of polyether to give diborane

$(B_2H_6)$ , sodium iodine and dihydrogen.

Answer: (C)

$B_2H_6,NaI$ and

$H_2$

In the Merck's process, the reagents involved in the preparation of hydrogen peroxide are:

0%
$BaO_{2}, HCl$
0%
$Na_{2}O_{2}, H_{2}SO_{4}$
0%
$BaO_{2}, H_{2}CO_{3}$
0%
$PbO_{2}, H_{2}O$

Explanation

Merck's method is as follows:-

$Na_2O_2+H_2SO_4\longrightarrow Na_2SO_4+H_2O_2$

Sodium peroxide is added to

$20$ % ice cold solution of

$H_2SO_4$ in small amounts with constant stirring.

On cooling, the

$Na_2SO_4.10H_2O$ crystals separate out and the solution contains

$30$ %

$H_2O_2$ . A pure sample of

$H_2O_2$ can be prepared by vacuum distillation.

Answer: (B)

$Na_2O_2, H_2SO_4$

Which reaction shows oxidising nature of

$H_{2}O_{2}$ ?

0%
$Ag_{2}O + H_{2}O_{2} \rightarrow Ag + H_{2}O + O_{2}$
0%
$MnO_{2} + H_{2} O_{2} + H_{2}SO_{4} \rightarrow MnSO_{4} + 2H_{2}O + O_{2}$
0%
$PbS + 4H_{2}O_{2} \rightarrow PbSO_{4} + 4H_{2}O$
0%
$K_{2}Cr_{2}O_{7} + H_{2}SO_{4} + 4H_{2}O_{2} \rightarrow K_{2}SO_{4} + 2CrO_{5} + 5H_{2}O$

Explanation

For (A),

${Ag}^{+1}_2O$ is reduced to

$Ag^o$

Therefore,

$H_2O_2$ acts as a reducing agent.

For (B)

${Mn}^{+4}$ is reduced to

${Mn}^{+2}$

Here,

$H_2O_2$ acts as a reducing agent.

For (C), There is no change in oxidation state of

$Pb$ .

For (D),

$Cr^{+6}$ is oxidised to

$Cr^{+10}$ .

Therefore,

$H_2O_2$ acts as an oxidising agent.

Answer: (D)

$K_2Cr_2O_7+H_2SO_4+4H_2O_2\longrightarrow K_2SO_4+2CrO_5+5H_2O$

Dihydrogen can be prepared on a commercial by the action of steam on hydrocarbons, when a mixture of CO and H

$_2$ gas is formed. It is known as________.

0%
water gas
0%
producer gas
0%
industrial gas
0%
fuel gas

Molecular mass of water ______.

0%
$18 u$
0%
$16 u$
0%
$15 u$
0%
$10 u$

$K_{a}$ for cyano acetic acid is

$3.5\ 10^{-3}$ . Then the degree of hydrolysis of

$0.05\ M$ sodium cyano acetate solution will have the value:

0%
$4.559\times 10^{-6}$
0%
$5.559\times 10^{-6}$
0%
$6.559\times 10^{-6}$
0%
$7.559\times 10^{-6}$

Explanation

Given: Degree of hydrolysis=

$0.05M$

$K_{a}$ for cyno acetic acid=

$3.5\times 10^{-3}$

Solution: The degree of hydrolysis is given by,

$\sqrt{\dfrac{K_{w}}{K_{a}c}}$

Substituting the values we get,

$\sqrt{\dfrac{1\times 10^{-14}}{3.5\times 10^{-3}\times 0.05}}$ (

$K_{w}$ =

$1\times 10^{-14}$ )

On solving we get,

$7.559\times 10^{-6}$

Hence, the correct option is (D).

Which of the following metals directly combine with hydrogen gas to give a hydride?

0%
Au
0%
Ni
0%
Ca
0%
Cu

Explanation

Amongst,

$Au$ ,

$Ni$ ,

$Ca$ and

$Cu$ ,

$Ca$ is the most reactive metal. So it easily combines with

$H_2$ to form hydride while the other metals do not combine directly.

The reaction can be given as:-

$Ca+H_2\longrightarrow CaH_2$

Which of the following statement is correct regarding hydrogen?

0%
Hydrogen shows +1 and -1 oxidation states
0%
Hydrogen is never liberated at anode
0%
Hydrogen has same ionisation enthalpy as that of alkali metals
0%
Hydrogen has same electronegativity as of halogens

Explanation

Hydrogen has +1 oxidation state in compounds with more electronegative elements e.g.

$HF$ . It has -1 oxidation state in compounds with more electropositive elements like

$NaH$ . In the above compounds with

$Na$ and

$F$ show +1 and -1 oxidation state respectively.

Syngas is a mixture of ?

0%
$CO_{2} + H_{2}$
0%
$CO + H_{2}$
0%
$CO + CO_{2}$
0%
$CO + O_{2}$

Explanation

Syngas also is known as synthetic gas or water gas is the name given to a mixture of carbon monoxide and hydrogen (

$CO$ and

$H_{2}$ ).

Which of the following properties of hydrogen is incorrect?

0%
Like halogens, hydrogen exists as a diatomic gas
0%
Like halogens, hydrogen exhibits - 1 oxidation state in its compounds with metals
0%
Like halogens, hydrogen is liberated at cathode
0%
The ionization energy of hydrogen is quite close to halogens

Explanation

Like halogens, hydrogen is liberated at anode, e.g.

2NaH

$\rightarrow 2Na + H_{2}$ (at anode

2NaCl

$\rightarrow 2Na + cl_{2}$ (at anode)

CBSE Questions for Class 11 Medical Chemistry Hydrogen Quiz 7 - MCQExams.com

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Practice Class 11 Medical Chemistry Quiz Questions and Answers

CBSE Questions for Class 11 Medical Chemistry Hydrogen Quiz 7 - MCQExams.com

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Practice Class 11 Medical Chemistry Quiz Questions and Answers

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