Correlate the items listed in Column I with those listed in Column II. Find out as many correlations as you can. Column I Column II (i) Synthesis gas (a) Na 2 Na 4 PO 3 6 (ii) Dihydrogen (b) Oxidizing agent (iii) Heavy water (c) Softening of water (iv) Calgon (d) Reducing agent (v) Hydrogen peroxide (e) Stoichiometric compounds of s-block elements (vi) Salt like hydrides (f) Prolonged electrolysis of water (g) Zn + NaOH (h) Zn + dil . H 2 SO 4 (i) Synthesis of methanol (j) Mixture of CO and H 2

(i) Synthesis gas: This synthesis gas is used for the production of methanol and many other hydrocarbons. CO g + 2 H 2 g → Catalyst Cobalt CH 3 OH l (j) Synthesis gas is a mixture of CO and H 2 , it is also known as syngas or water gas. (ii)Dihydrogen: Dihydrogen is a primary reducing agent. The ionic or saline hydrides are the stoichiometric compounds of dihydrogen formed with s-block elements. Example: NaH , KH etc. Laboratory method of dihydrogen synthesis is by the reaction of zinc granules with an aqueous alkali solution. Zn + 2 NaOH → Na 2 ZnO 2 Sodium zincate + H 2 Another laboratory method for synthesis of dihydrogen is by the reaction of zinc granules with dilute acid. Zn + 2 H + → Zn + 2 + H 2 Dihydrogen is used in the bulk synthesis of methanol. CO g + 2 H 2 g → Catalyst Cobalt CH 3 OH l (iii) Heavy water Heavy water can be prepared by the prolonged electrolysis of water. (iv) Calgon: Na 2 [ Na 4 ( PO 3 ) 6 ] is known as Calgon. It is used for softening of water, where the metal ion which causes hardness of water gets exchanged with sodium as follows: Na 6 P 6 O 18 → 2 Na + + Na 4 P 6 O 18 2 - M 2 + + Na 4 P 6 O 18 2 - → Na 2 MP 6 O 18 2 - + 2 Na + ( M = Mg , Ca ) (v) Hydrogen peroxide: Hydrogen peroxide acts as oxidizing as well as reducing agents in both acidic and basic medium. (vi) Salt like hydrides: The ionic or saline hydrides are the stoichiometric compounds of dihydrogen formed with s-block elements. Example: NaH , KH etc. Column I Column II (i) Synthesis gas (i) (j) Synthesis of methanol Mixture of CO and H 2 (ii) Dihydrogen (d) (e) (g) (h) (i) Reducing agent Stoichiometric compounds of s-block elements Zn + NaOH Zn + dil . H 2 SO 4 Synthesis of methanol (iii) Heavy water (f) Prolonged electrolysis of water (iv) Calgon (a) (c) Na 2 Na 4 PO 3 6 Softening of water (v) Hydrogen peroxide (b) (d) Oxidizing agent Reducing agent (vi) Salt like hydrides (e) Stoichiometric compounds of s-block elements

Match Column I with Column II for the given properties/applications mentioned therein. Column I Column II (i) H (a) Used in the name of perhydrol. (ii) H 2 (b) Can be reduced to dihydrogen by NaH . (iii) H 2 O (c) Can be used in hydroformylation of olefin. (iv) H 2 O 2 (d) Can be used in cutting and welding.

Atomic hydrogen is used for cutting and welding. Atomic hydrogen atoms are produced by dissociation of dihydrogen with the help of an electric arc, which is allowed to recombine on the surface to be welded to generate the temperature of 4000 K . Hydrogen is used in Hydroformylation of olefins. H 2 + CO + RCH = CH 2 → RCH 2 CH 2 CHO H 2 O is reduced to dihydrogen in the presence of NaH NaH ( s ) + H 2 O ( aq ) → NaOH ( aq ) + H 2 ( g ) H 2 O 2 is used as mild disinfectant, and sold in market as perhydrol. Column I Column II (i) H (d) Can be used in cutting and welding. (ii) H 2 (c) Can be used in the hydroformylation of olefin. (iii) H 2 O (b) Can be reduced to dihydrogen by NaH . (iv) H 2 O 2 (a) Used in the name of perhydrol.

Match the terms in Column I with the relevant item in Column II. Column I Column II (i) Electrolysis of water produces (a) atomic reactor (ii) Lithium aluminium hydride is used as (b) polar molecule (iii) Hydrogen chloride is a (c) recombines on the metal surface to generate high temperature (iv) Heavy water is used in (d) reducing agent (v) Atomic hydrogen (e) hydrogen and oxygen

(i) Electrolysis of water is the process by which water is decomposed into oxygen and hydrogen gas, when electric current is passed through it. Water molecule is decomposed in to H + and OH - ions, when electric current is passed through it. (ii) Lithium aluminium hydride is an inorganic compound with the chemical formula LiAlH 4 . This compound is used as a reducing agent in organic synthesis. (iii) Hydrogen chloride is a diatomic molecule, consisting of a hydrogen atom H and a chlorine atom Cl connected by a polar covalent bond. The chlorine atom is much more electronegative than the hydrogen atom, which makes this bond polar. (iv) Heavy water, deuterium is used in certain types of nuclear reactors, where it acts as a neutron moderator to slow down neutrons. (v) Atomic hydrogen atoms are produced by the dissociation of dihydrogen with the help of an electric arc. This releases a huge amount of energy ( 435 . 88 kJ ) . For this reason, atomic hydrogen is allowed to recombine on the surface to be welded to generate the desired temperature. Column I Column II (i) Electrolysis of water produces (e) hydrogen and oxygen (ii) Lithium aluminium hydride is used as (d) reducing agent (iii) Hydrogen chloride is a (b) polar molecule (iv) Heavy water is used in (a) atomic reactor (v) Atomic hydrogen (c) recombines on metal surface to generate high temperature

Match the items in Column I with the relevant item in Column II. Column I Column II (i) Hydrogen peroxide is used as a (a) zeolite (ii) Used in Calgon method (b) perhydrol (iii) Permanent hardness of hard water is removed by (c) sodium hexametaphosphate (d) propellant

(i) Hydrogen peroxide (formula H 2 O 2 ) is a chemical compound which is a combination of hydrogen and water. It is used as perhydrol and propellant. Perhydrol has hydrogen peroxide at a concentration of 30 % of weight by volume(w/v). (ii) Calgon method is used for softening hard water. Sodium hexametaphosphate has the chemical formula Na 6 O 18 P 6 or ( NaPO 3 ) 6 . The addition of Calgon to hard water causes the calcium and magnesium ions of hard water to displace sodium ions from the anion of Calgon. (iii) Permanent hardness of hard water is removed by adding sodium hexametaphosphate and zeolite to hard water. Zeolite contains a high percentage SiO 2 , which makes it a useful material for hardness removal. Column I Column II (i) Hydrogen peroxide is used as a (b)perhydrol (d)propellant (ii) Used in Calgon method (c)sodium hexametaphosphate (iii) Permanent hardness of hard water is removed by (a)zeolite (c)sodium hexametaphosphate

How will you account for 1045 bond angle in water

EASY

11th CBSE

IMPORTANT

NCERT Exemplar Chemistry - Class 11>Chapter 9 - Hydrogen>Short Answer Type>Q 61

Write redox reaction between fluorine and water.

MEDIUM

11th CBSE

IMPORTANT

NCERT Exemplar Chemistry - Class 11>Chapter 9 - Hydrogen>Short Answer Type>Q 62

Write two reactions to explain amphoteric nature of water.

HARD

11th CBSE

IMPORTANT

NCERT Exemplar Chemistry - Class 11>Chapter 9 - Hydrogen>Matching Type>Q 63

Correlate the items listed in Column I with those listed in Column II. Find out as many correlations as you can.

Column I		Column II
(i)	Synthesis gas	(a)	${Na}_{2} [{Na}_{4} {({PO}_{3})}_{6}]$
(ii)	Dihydrogen	(b)	Oxidizing agent
(iii)	Heavy water	(c)	Softening of water
(iv)	Calgon	(d)	Reducing agent
(v)	Hydrogen peroxide	(e)	Stoichiometric compounds of s-block elements
(vi)	Salt like hydrides	(f)	Prolonged electrolysis of water
		(g)	$Zn + NaOH$
		(h)	$Zn + dil . H_{2} {SO}_{4}$
		(i)	Synthesis of methanol
		(j)	Mixture of $CO$ and $H_{2}$

EASY

11th CBSE

IMPORTANT

NCERT Exemplar Chemistry - Class 11>Chapter 9 - Hydrogen>Matching Type>Q 64

Match Column I with Column II for the given properties/applications mentioned therein.

Column I		Column II
(i)	$H$	(a)	Used in the name of perhydrol.
(ii)	$H_{2}$	(b)	Can be reduced to dihydrogen by $NaH$ .
(iii)	$H_{2} O$	(c)	Can be used in hydroformylation of olefin.
(iv)	$H_{2} O_{2}$	(d)	Can be used in cutting and welding.

HARD

11th CBSE

IMPORTANT

NCERT Exemplar Chemistry - Class 11>Chapter 9 - Hydrogen>Matching Type>Q 65

Match the terms in Column I with the relevant item in Column II.

Column I		Column II
(i)	Electrolysis of water produces	(a)	atomic reactor
(ii)	Lithium aluminium hydride is used as	(b)	polar molecule
(iii)	Hydrogen chloride is a	(c)	recombines on the metal surface to generate high temperature
(iv)	Heavy water is used in	(d)	reducing agent
(v)	Atomic hydrogen	(e)	hydrogen and oxygen

HARD

11th CBSE

IMPORTANT

NCERT Exemplar Chemistry - Class 11>Chapter 9 - Hydrogen>Matching Type>Q 66

Match the items in Column I with the relevant item in Column II.

Column I		Column II
(i)	Hydrogen peroxide is used as a	(a)	zeolite
(ii)	Used in Calgon method	(b)	perhydrol
(iii)	Permanent hardness of hard water is removed by	(c)	sodium hexametaphosphate
		(d)	propellant

MEDIUM

11th CBSE

IMPORTANT

NCERT Exemplar Chemistry - Class 11>Chapter 9 - Hydrogen>Long Answer Type>Q 69

Atomic hydrogen combines with almost all elements but molecular hydrogen does not. Explain.

HARD

11th CBSE

IMPORTANT

NCERT Exemplar Chemistry - Class 11>Chapter 9 - Hydrogen>Long Answer Type>Q 70

How can

D_{2} O

be prepared from water? Mention the physical properties in which

D_{2} O

differs from

H_{2} O

. Give at least three reactions of

D_{2} O

showing the exchange of hydrogen with deuterium.

How will you account for $104.5 °$ bond angle in water?

Important Questions on Hydrogen

Learn and Prepare for any exam you want !

How will you account for 104.5° bond angle in water?

Important Questions on Hydrogen

Learn and Prepare for any exam you want !

How will you account for $104.5 °$ bond angle in water?