both electropositive as well as electronegative

neither electropositive nor electronegative

MCQ Questions for Class 11 Medical Chemistry Hydrogen Quiz 3

Hydrolith, a source of hydrogen is :

0%
$NaH$
0%
$CaH_{2}$
0%
$LiH$
0%
$BaH_{2}$

Explanation

A salt like binary compound

$(CaH_2)$ , calcium hydride used as a reducing agent and source of hydrogen.

STATEMENT-1: Alkaline earth metals form polymeric hydrides.
STATEMENT-2: Only

$Be$ and

$Mg$ among alkaline earth metals forms polymeric hydrides.

0%
Statement-1 is true, Statement-2 is true; Statement-2 is a correct explanation for Statement-1
0%
Statement-1 is true, Statement-2 is true; Statement-2 is not a correct explanation for Statement-1
0%
Statement-1 is true, Statement-2 is false
0%
Statement-1 is false, Statement-2 is true

Which element forms hydride?

0%
$Cr$
0%
$Mo$
0%
$W$
0%
$Sg$

Explanation

Chromium forms hydride when it reacts with hydrogen.

It forms the hydrides having the following formula

$CrH_{0.5}, CrH, CrH_2$ .

Hence, option A is correct.

$20$ ml of

$H_2O_2$ after acidification with dil

$H_2SO_4$ . required

$30$ ml of N/2

$KMnO_4$ for complete oxidation. Calculate the % of

$H_2O_2$ in g/lit.

0%
10.75 g/lit
0%
11.75 g/lit
0%
12.75 g/ lit
0%
13.75 g/lit

Explanation

$15$ milli equivalents of

$KMnO_{4}$ require

$15$ milli equivalents of

$H_{2}O_{2}$ .

Hence,

$15$ milli equivalents are present in

$20$ ml of sample.

Thus, strength is

$15 \times \dfrac{17}{20} = 12.75$ .

Which is polymeric hydride?

0%
$CaH_{2}$
0%
$MgH_{2}$
0%
$BaH_{2}$
0%
$SrH_{2}$

Explanation

$MgH_2$ forms a polymeric hydride by forming bridge bonds with hydrogen.

Which halogen reacts only partially with hydrogen even at high temperature and in the presence of a catalyst?

0%
$\mathrm{F}_{2}$
0%
$\mathrm{Cl}_{2}$
0%
$\mathrm{B}\mathrm{r}_{2}$
0%
$\mathrm{I}_{2}$

Explanation

Reactivity order of halogens:

$F_{2}>Cl_{2}>Br_{2}>I_{2}$
There is small difference in electronegativity of hydrogen and iodine. So, it does not readily react with hydrogen whereas other halogens do.

Silicon hydrides are called:

0%
silicones
0%
silicates
0%
silicides
0%
silanes

Explanation

Silicones are organo-silicon polymers that have

$R_2SiO$ as a repeating unit whereas silicates are compounds having the repeating unit as

$SiO_4^{4-}$ .

A silicide is a compound that has silicon with (usually) more electropositive elements.

Silanes are silicon-hydrogen compounds.

Which one of the following pairs of reactants does not produce oxygen when they react with each other?

0%
${F}_{2},\ {N}{a}{O}{H}$ solution (hot, conc.)
0%
${F}_{2},\ {H}_{2}{O}$
0%
${Cl}_{2},\ {N}{a}{O}{H}$ solution (cold, dilute)
0%
${C}{a}{O}{C}l_{2},\ {H}_{2}{S}{O}_{4}$ (dilute, small amount)

Explanation

1. Fluorine reacts with hot concentrated

$NaOH$ solution to form oxygen.

The reaction is as follows:

$10F_2 + 20 NaOH \rightarrow 20 NaF + 10 O_2 + H_2O$

2. Fluorine reacts with water to form oxygen.

$2 F_2 + 2 H_2O \rightarrow O_2 + 4 F^{-} + 4 H^{+}$ .

3. Chlorine reacts with cold dilute

$NaOH$ solution to form sodium chloride, sodium hypochloride and water. Oxygen is not formed in the reaction.

$Cl_2+NaOH \rightarrow NaCl+NaOCl+H_2O$

$CaOCl_2$ reacts with small amount of dilute

$H_2SO_4$ to produce oxygen.

$2CaOCl_2+H_2SO_4 \rightarrow CaCl_2+CaSO_4+2HClO$

$HClO \rightarrow HCl + O$

Hence, the only reaction among the four which produce no oxygen is between

$Cl_2$ and

$NaOH$ (cold, dilute).

Hence, the correct option is C.

Which of the following exists as associated molecules due to hydrogen bonding?

0%
$NH_{3}$
0%
$H_{2}O$
0%
$HF$
0%
$HCl$

The stability of hydrogen halides is in the order of:

0%
$HF>HI>HBr>HCl$
0%
$HI>HBr>HCl>HF$
0%
$HF>HCl>HBr>HI$
0%
$HCl>HBr>HI>HF$

Explanation

Due to large difference in electronegativity of upper halogens and hydrogen, they are more stable than lower hydrogen halide.

$\therefore$ Stability order:

$HF>HCl>HBr>HI$ .

Hence, option C is correct.

Which of the following is a reducing agent and undergoes hydrolysis?

0%
$CH_{4}$
0%
$C_{2}H_{6}$
0%
$C_{3}H_{8}$
0%
$SiH_{4}$

Explanation

Carbon compounds are unable to undergo hydrolysis due to absence of

$d$ orbitals. However,

$Si$ compounds can easily undergo hydrolysis due to the same fact that it has vacant d orbitals.

Boiling point is least for:

0%
$HF$
0%
$HCl$
0%
$HBr$
0%
$HI$

Explanation

Correct Answer: Option B

Explanation:

Among the hydrogen halides, $HI$ is ionic while $HCl$ , $HBr$ and $HF$ are covalent.

The boiling points of ionic compounds are higher than that of covalent compounds.

The boiling point of covalent compounds is proportional to their molecular mass.

But in $HF$ , there is intermolecular hydrogen bonding. So $HF$ has a higher boiling point than $HCl$ .

Hence, the boiling point of $HCl$ is the lowest.

Bleaching action of chlorine occurs in the presence of :

0%
oxygen
0%
moisture
0%
dry air
0%
sunlight

Explanation

$Cl_{2}+\underset{(H_{2}O)}{\text{moisture}} \rightarrow HCl+HClO$
Bleaching action of chlorine is due to

$HClO$ and therefore,

$Cl_{2}$ needs moisture for its bleaching action.

Which of the following is not used for disinfection of drinking water?

0%
Chlorine
0%
Phenyl
0%
Chloramine
0%
Ozone

In context with the industrial preparation of hydrogen from water gas

$(CO +\mathrm{H}_{2})$ , which of the following is the correct statement?

0%
$\mathrm{H}_{2}$ is removed through occlusion with Pd
0%
$CO$ is oxidised to $\mathrm{C}\mathrm{O}_{2}$ with steam in the presence of a catalyst followed by absorption of $\mathrm{C}\mathrm{O}_{2}$ in alkali
0%
$CO$ and $\mathrm{H}_{2}$ are fractionally separated using differences in their densities
0%
$CO$ is removed by absorption in aqueous $\mathrm{C}\mathrm{u}_{2}\mathrm{C}l_{2}$ solution

0%
Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
0%
Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
0%
Assertion is correct but Reason is incorrect
0%
Both Assertion and Reason are incorrect

Explanation

The present position of hydrogen with alkali metals is not justiciable since it shows some properties of alkali metals and some properties of halogens. Hydrogen is a non-metallic diatomic gaseous element. Hydrogen has high

$IP$ value comparable with halogens in contrast to

$IA$ group elements having a low

$IP$ values. Hydrogen also forms

$H^-$ ion whereas alkali metals do not form. However, it shows certain similarities with

$IA$ group. They are a formation of halides of formula Mcls formation of

$H^+$ ion, electropositive nature etc. Therefore, its position is controversial.

Water containing heavier isotope of oxygen is know as _______water.

0%
hard
0%
soft
0%
heavy
0%
light

Hydrogen occupies a unique position in Modern Periodic Table.

0%
True
0%
False

Explanation

Hydrogen has electron configuration of

$1s^{1}$ .To become stable it can either accept to get helium configuration that is a stable configuration or it can even donate one electron. Hence it is very confusing where to place either in the metals group as it donates or in nonmetal group as it accepts an electron. Hence it occupies a unique position in the periodic table.

The molecular weight of heavy water is _________ than ordinary water.

0%
lower
0%
higher
0%
same
0%
none of the above

Hydrogen gas is liberated by the action of aluminium with a concentrated solution of _________.

0%
$NaHCO_3$
0%
$Na_2CO_3$
0%
$NaOH$
0%
none of these

Explanation

$2Al+2NaOH+2{ H }_{ 2 }O\rightarrow 2NaAl{ O }_{ 2 }+3{ H }_{ 2 }$

This reaction is extremely quick and produces a lot of energy.

This reaction occurs because

$Al$ is always covered by a layer of un-reactive

${ Al }_{ 2 }{ O }_{ 3 }$ layer has to be taken down first.

Which of the following given element has one electron, one proton and no neutron?

0%
$H$
0%
$Li$
0%
$Cl$
0%
$He$

Explanation

The atomic number of Hydrogen is

$(Z)$ = 1 and it's mass number

$(A)$ is

$1$ .

Therefore, number of neutrons

$= A-Z = 0$ . Hence, it is represented by

$_{1}{H}^1$ .

Hydrogen is the ________ element on the earth.

0%
most abundant
0%
heaviest
0%
lightest
0%
none of these

Explanation

$H$ is the lightest element on earth as there is only

$1$ proton and

${ 1e }^{ - }$ . All the other elements have more than 1 electrons and protons along with neutrons.

$2Na_2O_2 + \underset{cold}{ 2H_2O} \rightarrow$ ______

$+H_2O_2$

0%
$Na_2O$
0%
$NaOH$
0%
$NaO$
0%
none of these

State whether the statement is true or false:

We can cook pulses easily in hard water.

0%
True
0%
False

________ element has one electron in the outermost shell and attains duplet configuration after accepting one more electron and attains stability.

0%
Helium
0%
Hydrogen
0%
Lithium
0%
Carbon

Explanation

Hydrogen has

${ 1e }^{ - }$ in outermost shell, in order to achieve stability either

${ e }^{ - }$ to be removed or added. When added it acquires a stable configuration forming duplet.

As the rain water is the purest form of water, this can be used in lab due to:

0%
presence of ions
0%
absence of ions
0%
good smell
0%
easy availability

Hydrogen readily combines with these elements?

0%
Na
0%
K
0%
Ca
0%
Zn

Explanation

${ H }_{ 2 }$ easily reacts with

$Na, Ca, K$ as they are highly reactive metals and are placed at the top of the reactivity series.

${ 2Na }+{ H }_{ 2 }\rightarrow 2NaH$

$2K+{ H }_{ 2 }\rightarrow 2KH$

$Ca+{ H }_{ 2 }\rightarrow CaH_2$ .

Silver reacts with hydro chloric acid to give ________.

0%
$AgCl$
0%
$H_2$
0%
$AgH$
0%
no reaction

Explanation

Silver cannot replace

$H$ from

$HCl$ as it is placed at bottom of

$H$ in reactivity series, hence less reactive then

$H$ .

Water contains 88.89% of A by weight is decomposed into its elements B and oxygen. Pure C is a poor conductor of electricity and hence it is acidified using dilute sulphuric acid. When electric current is passed through acidulated water, using platinum electrones, hydrogen gas is evolved at cathode and oxygen gas is evolved at D.

What is 'C'?

0%
Oxygen
0%
Hydrogen
0%
Water
0%
Sulphuric acid

Explanation

Percentage of oxygen in water

$\displaystyle = \frac{weight\ of\ oxygen\ in\ water}{weight\ of\ water} \times 100$

$\displaystyle = \frac{16}{18} \times 100$

$=$ 88.89%

Thus, water contains 88.89% of oxygen (A)

On decomposition of water we get hydrogen and oxygen.

So, B is hydrogen

Pure water is a poor conductor of electricity and when acidified by adding sulphuric acid it can conduct electricity hence, C is water.

When hydrogen reacts with oxygen, oxygen is __________ is formed.

0%
oxidized and water
0%
reduced and water
0%
reduced and ozone
0%
none of these

Explanation

${ 2H }_{ 2 }+{ O }_{ 2 }\rightarrow { 2H }_{ 2 }O$

Addition of hydrogen to any molecule/element is the reduction of the element.

When hydrogen is added with oxygen, it forms water.

When water is boiled to 100 $^{\circ}$ C, it converts into steam which on condensation gives back water. Here, the heat given out is called latent heat of condensation which is equal to the latent heat of vapourisation.

0%
True
0%
False

Explanation

Latent heat is defined as the energy required by molecules to change phase at a constant temperature. If the phase change is solid to liquid it is called latent heat of fusion, liquid to gas is latent heat of vapourization, gas to liquid is latent heat of condensation
At 100

$^{ \circ }$ :

$H_2O(l) \rightarrow H_2O(g)(steam)$

$H_2O(g) \rightarrow H_2O(l)$
Thus latent heat of vaporization, is same as latent heat of condensation
option A is correct

One of the methods for the manufacture of

$H_2O_2$ involves the auto-oxidation of:

0%
2- ehtylanthraquinol
0%
hydrated barium peroxide
0%
an alkali solution
0%
50% $H_2SO_4$

Explanation

Hydrogen peroxide can be obtained by the auto-oxidation of 2-ethyl anthraquinol.

2-Ethylanthraquinol

$\rightleftharpoons$ oxidized product

$+\ H_2O_2$

The reduced product is dissolved in a mixture of benzene and cyclohexanol and when air is passed through this, it is oxidised back to 2-Ethylanthraquinone and hydrogen peroxide is also produced along with.

This process is very cheap because 2-Ethylanthraquinone can be used again and again.

Rogue element in the periodic table is______.

0%
oxygen
0%
hydrogen
0%
astatine
0%
rhenium

In which property listed below hydrogen does not resemble alkali metals?

0%
Tendency to form cation
0%
Nature of oxide
0%
Combination with halogens
0%
Reducing character

Explanation

Hydrogen shows all other properties like alkali metals (form cation, combine with halogens, reducing nature) but nature of oxide is different than metals because oxide of metals are basic in nature whereas oxide of Hydrogen are amphoteric in nature i.e.

$H_2O$ .
Option B is correct.

Hydrogen has the tendency to lose one electron and form

$H^{+}$ . In this respect, it resembles:

0%
alkali metals
0%
carbon
0%
alkaline earth metals
0%
halogens

Hydrogen peroxide has a

0%
linear structure
0%
closed chain structure
0%
closed book type structure
0%
half open book type structure

Explanation

The structure of

$H_2O_2$ is not planar but open book structure. The O-O-H bond angle is 101.5

$^o$ and the O-O single bond distance is 1.48

$A^o$

Hydrogen is:

0%
electropositive
0%
electronegative
0%
both electropositive as well as electronegative
0%
neither electropositive nor electronegative

Explanation

Hint: Hydrogen has an electronegativity of $2.1$

Correct Answer: Option C

Explanation:

Hydrogen is one of the most unique elements of the periodic table. It can act as both an electropositive element as well as an electronegative element depending on which element it is reacting with.

When it is reacting with alkali metals and alkaline earth metals, it will be acting as an electronegative element and forms ionic hydrides:

$2Na + H_2 \rightarrow 2Na^+H^-$

When it is reacting with halogens, it will be acting as an electropositive element. Hence a partial positive charge gets developed on it.

$H_2 + F_2 \rightarrow 2 \ H^{\delta+}-F^{\delta -}$

The conversion of atomic hydrogen into molecular hydrogen is______.

0%
endothermic change
0%
exothermic change
0%
photochemical change
0%
nuclear change

Explanation

Reaction:

$2H\rightarrow H_2+heat$

So, its a exothermic change.

Which property of water is used while washing clothes?

0%
Odour
0%
Colour
0%
Solubility
0%
Sand

Amongst the following the total number of elements, which produce

$H_2$ gas with sodium hydroxide is:
Zn, Al, Sn, Pb, P, Si

0%
3
0%
4
0%
5
0%
6

Explanation

$Zn+2NAOH\rightarrow Na_2ZnO_2+H_2\uparrow$

$2Al+2NaOH+H_2O\rightarrow 2NaAlO_2+3H_2\uparrow$

$Sn+2NaOH+H_2O\rightarrow Na_2SnO_3+2H_2\uparrow$

$Pb+2NaOH+H_2O\rightarrow Na_2PbO_3+2H_2\uparrow$

$Si+2NaOH+H_2O\rightarrow Na_2SiO_3+2H_2\uparrow$

$P_4+3NaOH+3H_2O\rightarrow PH_2\uparrow +3NaH_2PO_2$

Hydrogen does not combine with:

0%
antimony
0%
sodium
0%
bismuth
0%
helium

Explanation

Hint: $He$ is a noble element. It does not combine with any other element.

Correct Answer: Option D

Explanation:

Hydrogen is an element that combines with almost every other element in the periodic table, except noble gases.

It reacts with

$s-block$ elements to form ionic hydrides, with

$p-block$ elements to form covalent hydrides, and with

$d-block$ elements to form interstitial hydrides.

However it doesn't combine with noble gases,

$Sb + H_2 \xrightarrow{\Delta} SbH_3$

$Na + H_2 \xrightarrow{\Delta} NaH$

$Bi + H_2 \xrightarrow{\Delta} BiH_3$

$He + H_2 \rightarrow no\ reaction$

$H_{2}O_{2}$ can be obtained when following reacts with

$H_{2}SO_{4}$ except with_______.

0%
$PbO_{2}$
0%
$BaO_{2}$
0%
$Na_{2}O_{2}$
0%
$SrO_{2}$

Explanation

The laboratory preparation of hydrogen peroxide was based on the technique that Thenard used. In this technique, barium nitrate, purified by recrystallization, was decomposed by heating in air in a porcelain retort. The resulting oxide was further oxidized by heating in a stream of oxygen to a dull red heat. The barium peroxide which formed was then dampened, ground, and dissolved in hydrochloric acid. A slight excess of sulfuric acid was then added to precipitate barium sulfate and regenerate hydrochloric acid. The procedure of barium peroxide solution and sulfate precipitation was repeated several times in the same solution to increase the peroxide concentration. But

$PbO_{2}$ can not be used in this process instead of

$BaO_{2}$ .

Reaction:

$BaO_2.8H_2O + H_2SO_4 \rightarrow BaSO_4 + H_2O_2 + 8H_2O$ .

Under what conditions of temperature and pressure, the formation of molecular hydrogen from atomic hydrogen will be favoured most?

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

Explanation

Reaction:

$2H\rightarrow H_2+\text{heat}$
So, according to Le Chatelier's principle, low temperature and high pressure is favored.

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

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

Explanation

In laboratory,

$H_2O_2$ is prepared by Merck's process. It is prepared by adding calculated amounts of sodium peroxide to ice cold dilute

$(20\%)$ solution of

$H_2SO_4$ .

$Na_2O_2+ H_2SO_4 \rightarrow Na_2SO_4+ H_2O_2$ .

Which of the following is a true structure of

$H_{2}O_{2}$ ?

0%
Linear
0%
Open book
0%
Bent
0%
Tetrahedrak

In laboratory,

$H_{2}O_{2}$ is prepared by the action of:

0%
cold $H_{2}SO_{4}$ and $BaO_{2}$
0%
aqueous alkali on $Na_{2}O_{2}$
0%
$MnO_{2}$ and cold $H_{2}SO_{4}$
0%
dilute $HCl$ and $MnO_{2}$

Explanation

In laboratory,

$H_{2}O_{2}$ is preparedby the following reaction:

$BaO_2.8H_2O + H_2SO_4 \rightarrow BaSO_4 + H_2O_2 + 8H_2O$

Decomposition of

$H_{2}O_{2}$ is retarded by__________.

0%
Acetanilide
0%
$MnO_{2}$
0%
Zinc
0%
finely divided metal

Explanation

Decomposition of

$H_{2}O_{2}$ can be retarded small amounts of acid, glycerol, alcohol, acetanilide.

The

$O-O-H$ bond angle in

$H_{2}O_{2}$ is:

0%
$106^\circ$
0%
$109^\circ 28'$
0%
$120^\circ$
0%
$94^\circ$

$HCl$ is added to the following oxides, which one would give

$H_{2}O_{2}$ ?

0%
$BaO_{2}$
0%
$MnO_{2}$
0%
$PbO_{2}$
0%
$NO_{2}$

Explanation

The laboratory preparation of hydrogen peroxide was based on the technique that Thenard used.

In this technique, barium nitrate, purified by recrystallization, was decomposed by heating in air in a porcelain retort. The resulting oxide was further oxidized by heating in a stream of oxygen to a dull red heat.

The barium peroxide which formed was then dampened, ground, and dissolved in hydrochloric acid.

A slight excess of sulfuric acid was then added to precipitate barium sulfate and regenerate hydrochloric acid. The procedure of barium peroxide solution and sulfate precipitation was repeated several times in the same solution to increase the peroxide concentration.
Reaction:

$BaO_2.8H_2O + H_2SO_4 \rightarrow BaSO_4 + H_2O_2 + 8H_2O$ .

Which one of the following methods can be used to test the presence of water?

0%
Smell the liquid
0%
Add anhydrous copper sulphate and look for a colour change
0%
Taste the liquid
0%
Litmus paper with the solution

Explanation

The reaction between anhydrous copper sulfate and water is reversible:

Anhydrous copper sulfate (white) $+$ water $=$ Hydrated copper sulfate (blue)

$CuSO4 + 5H_2O \rightarrow CuSO_4.5H_2O$ .

White anhydrous amorphous copper sulfate combines with $5$ molecules of water to form hydrous blue copper sulfate (blue vitriol).

CBSE Questions for Class 11 Medical Chemistry Hydrogen Quiz 3 - MCQExams.com

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Practice Class 11 Medical Chemistry Quiz Questions and Answers

CBSE Questions for Class 11 Medical Chemistry Hydrogen Quiz 3 - MCQExams.com

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Practice Class 11 Medical Chemistry Quiz Questions and Answers

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