94420 + Interview Questions in Chemistry in Class 12 Page 605 InterviewSolution

30201.	Theheat liberated when 1.89 g of benzoic acid burnt in a bomb calorimeter at 25^(@)C increases the temperature of 18.94 kg of water by 0.632^(@)C. If the specific heat of water at 25^(@)C is 0.998cal/g-deg, the value of the heat combustion of benzoic acid is
Answer» 771.1 KCAL 871.2 kcal 881.1 kcal 981.1 kcal Solution :`Q=(18.94xx0.632xx0.998xx122)/(1.89)=771.1 kcal`.

Discussion

30202.	The heat liberated when 1.89 g of benzoic acid is burnt in a bomb calorimeter at 25^@C increase the temperature of 18.94 kg of water by 0.632^@C. If the specific heat of water at 25^@C is 0.998 cal/g-deg, the value of the heat of combustion of benzoic acid is
Answer» 881.1 kcal 771.124 kcal 981 kcal 871.2 kcal Answer :B

Discussion

30203.	The heat evolved in the combustion of benzene is given by: C_(6)H_(6)(l) + 7(1/2)O_(2)(g) to 3H_(2)(l) + 6CO_(2)(g) , DeltaH = -781.0 kcal//"mol"^(-1), When 156 g of C_(6)H_(6) is burnt in an open container, the amount of heat energy released will be:
Answer» `150.2 kcal "MOL"^(-1)` `1562.0 kcal "mol"^(-1)` `6528.2 KJ "mol"^(-1)` `2448.5 kJ "mol"^(-1)` Answer :B::C

Discussion

30204.	The heat evolved in the combustion of benzene is given by C_(6)H_(6)+7(1)/(2)O_(2)rarr6CO_(2)(g)+3H_(2)O(l),DeltaH=-3264.6 kJWhich of the following quantities of heat energy will be evolved when 39_(g)C_(6)H_(6) are burnt
Answer» 816.15 KJ 1632.3 kJ 6528.2 kJ 2448.45 kJ Solution :78g of benzene on COMBUSTION PRODUCES HEAT =-3264.6 kJ `therefore" 39 g will produce = "(-3264.6)/(2)=-1632.3 kJ`.

Discussion

30205.	The heat evolved in the combustion of benzene is given by C_(6)H_(6)(l) + 7 (1/2)O_(2)(g) to 3H_(2)O(l) + 6CO_(2)(g), DeltaH = -781.0 kcal//"mol"^(-1) When 156 g of C_(6)H_(6) is burnt in an open container, the amount of heat energy released will be
Answer» 150.2 kcal `"MOL"^(-1)` 1562.0 kcal `"mol"^(-1)` `6528.2 KJ"mol"^(-1)` `2448.5 kJ "mol"^(-1)` Answer :B::C

Discussion

30206.	The heat evolved in the combustion of112 litre of water gas (mixture of equal volume of H_(2) and CO) is H_(2)(g) + 1/2O_(2)(g) to H_(2)O(g), DeltaH=-241.8 kJ CO(g) + 1/2O_(2)(g) to CO_(2)(g), DeltaH=-283 kJ
Answer» `241.8` KJ 283 kJ 1312 kJ 1586 kJ ANSWER :C

Discussion

30207.	The heat evolved during the combustion of 112 litre of water gas (mixture of equal volume of H_2 and CO) is :GivenH2 (g)+1/2O2 (g)=H2 O(g);ΔH=−241.8kJCO(g)+1/2O2 (g)=CO2 (g);ΔH=−283kJ
Answer» 241.8 kJ 283 kJ 1312 kJ 1586 kJ Answer :C

Discussion

30208.	The heat evolved during the combination of 24 g C and 128 g S following the change isC+S_(2)rarrCS_(2),DeltaH=22.0 kcal
Answer» 11 KCAL 32 kcal 44 kcal 22 kcal Solution :`22.0xx2=44 kcal`.

Discussion

30209.	The heat energy required to ionise the following molecules is given as follows N_(2)(g) overset(DeltaH_(1))to H_(2)^(o+)(g),O_(2)(g) overset(DeltaH_(2))to O_(2)^(+)(g) Li_(2)(g) overset(DeltaH_(3)) to Li_(2)^(o+)(g),C_(2)(g) overset(DeltaH_(4))to C_(2)^(o+)(g) The correct decreasing order of energy in terms of heat
Answer» `DeltaH_(1) gt DeltaH_(3) gtDeltaH_(2) gt DeltaH_(4)` `DeltaH_(2) gt DeltaH_(3) gt DeltaH_(1) gt DeltaH_(4)` `DeltaH_(3) gt DeltaH_(4)gt DeltaH_(1) gt DeltaH_(2)` `DeltaH_(3) gt DeltaH_(1) gt DeltaH_(4) gt DeltaH_(2)` SOLUTION :Enthalpy of IONISATION depends upon the size of molecules. LARGER the size lesser will be ionisation energy.

Discussion

30210.	The heat evolved during neutralisation is maximum in the reaction of:
Answer» `NH_4OH and CH_3COOH` `NH_4OH` and HCL `NAOH and CH_3COOH` `NaOH and HCl` ANSWER :D

Discussion

30211.	The heat content of a system is called
Answer» <P>INTERNAL energy Entropy Free energy Enthalpy Solution :`q_(p)=DELTAH`.

Discussion

30212.	The heat change in a chemical reaction at constant pressure is:
Answer» `TRIANGLEH` `TRIANGLEU` `triangleT` `triangleV` ANSWER :A

Discussion

30213.	The heat change taking place during the reaction H_2O(l)rarrH_2O(g) is ?[ Given triangleH_1=H_2O(g)=-57 kal, TriangleH_f=H_2O(l)=-68.3kcal]:
Answer» `+11.3 KCAL` `-11.3 kcal` `-115.3 kcal` `+115.3 kcal` ANSWER :A

Discussion

30214.	The heat change for the reaction. CO + (1)/(2) O_(2) rarr CO_(2) is called
Answer» HEAT of reaction heat of formation heat of neutralisation heat of combustion. Answer :D

Discussion

30215.	The heat change for the following reaction at 298K and at constant pressure is +7.3 kcal A_(2)B(s) rarr 2A(s) + 1//2 B_(2)(g), DeltaH =+7.3 kcal The heat change at constant volume would be C(s)+2S(s)rarrCS_(2)(l) is known as
Answer» HEAT of VAPORIZATION Heat of solution Heat of fusion Heat of FORMATION Solution :ACCORDING to the DEFINITION of heat of formation.

Discussion

30216.	The heat change for the following reaction at 298K and at constant pressure is +7.3 kcal A_(2)B(s) rarr 2A(s) + 1//2 B_(2)(g), DeltaH =+7.3 kcal The heat change at constant volume would be
Answer» 7.3 KCAL More than 7.3 Zero None of these Solution :`DeltaH=DeltaE+DeltanRT or DeltaE=DeltaH-DeltanRT` `thereforeDeltaE=+7.3-(1)/(2)xx0.002xx298=7.3-0.298=7` kcal.

Discussion

30217.	The heat change DeltaH for the reaction 2CO+O_(2)rarr2CO_(2),DeltaH=-135 kcal is called
Answer» Heat of formation Heat of reaction Heat of combustion Heat of solution Solution :ONE mole of a substance is COMPLETELY OXIDIZED in air.

Discussion

30218.	The heat change at constant volume (q_(v)) is equal to
Answer» `DELTAU` `DELTAH` RT `DELTAG` ANSWER :A

Discussion

30219.	The heat capacity of liquid water is 75.6 J/mol K, while the enthalpy of fusion of ice is 6.0 kJ/mol. What is the smallest number of ice cubes at 0^(@)C, each containing 9.0g of water, needed to cool 500 g of liquid water from 20^(@)C to 0^(@)C ?
Answer» 1 7 14 None of these Answer :C

Discussion

30220.	Theheat capcity of liquildwater is 75.6 J //mol .K, while theenthalpy of fusion of ice is6.0 kJ//mol, What is the smallestnumberof icecubes at0^(@) C,eachcontainig9.0g of water ,needed to cool500 gofliquildwaterfromj 20^(@)to 0^(@) C ?
Answer» 1 7 14 None of these Solution :`DeltaU =Q + W` ` = 100 -[1 XX 1 + 1//2xx 1]"bar" m^(3)""("1 bar " m^(3) = 10^(5) J= 100 k)` `= - 50 kJ`

Discussion

30221.	The heat capacity at constant volume of an ideal gas consisting of monatomic molecules is 3//2 R ( where R is the gas constant ) . The heat capacity at constant pressure is :
Answer» R `( 5)/( 2) R ` ` ( 1)/( 2) R ` `( 3)/( 2) R ` SOLUTION :New PRESSURE `= ( 40)/( 100)` Since PV is constant, new volume should be `( 100)/( 40) ` times i.e. `( 100)/( 40) xx 100 = 250` ml Volume of bulb A= 100ml Volume of bulb B = 250 - 100 = 150 ml

Discussion

30222.	The hcp and ccp structure of a given element. (Given radius of element id same in both structures)
Answer» have same density have same distance between TWO CONSECUTIVE LAYERS (A&B) have same co-ordination number have same fraction of unoccupid space. Answer :ABCD

Discussion

30223.	The h.c.p. and c.c.p. structures for a given crystal system of equal - sized spheres are expected to have
Answer» the same VOLUME, `1.33 pi r^(3)` the same NUMBER of particles within the given UNIT cell the same ratio, 0.74, of the total sphere volume to the unit - cell volume All of the above Answer :A::C

Discussion

30224.	The HCC bond angle in acetylene is:
Answer» `90^@` `120^@` `109^@ 28'` `180^@` ANSWER :D

Discussion

30225.	The hardness of water is estimated by:
Answer» CONDUCTIVITY method EDTA method Titrimetric method Distillation method Answer :B

Discussion

30226.	The hardness of metal increases with increase in number of …… involved in metallic bonding.
Answer» Atoms Molecules Electrons All Answer :C

Discussion

30227.	The hardness Cr is due to ….And metallic lusture is due to
Answer» Covalent BOND, METALLIC bond Covalent bond, hydrogen bond Metallic bond, covalent bond Metallic bond, hydrogen bond Solution :Covalent bond is CONSTITUTED by electrons of d-orbitals and luster is due to FREE electrons of s-orbital in metallic bond.

Discussion

30228.	The hardest substance amongst the following is
Answer» `Be_(2)C` titanium SiC `B_(4)C` SOLUTION :`B_(4)C` is the hardest SUBSTANCE after diamond and BN.

Discussion

30229.	The hardest substance amonts the following is
Answer» `Be_(2)C` Graphite Titanium `B_(4)C` Solution :`B_(4)C` is the hardest SUBSTANCE ALONG with DIAMOND.

Discussion

30230.	The hard plastic covers of telephones are made of polymers of
Answer» ACRYLONITRILE STYRENE Fluoromethane PHENOL formaldehyde ANSWER :D

Discussion

30231.	The halogens, which is attacked by conc. HNO_(3) are :
Answer» `F_(2)` `Cl_(2)` `Br_(2)` `I_(2)` Solution :CONCENTRATED nitric ACID OXIDISES `I_(2)` to `HIO_(3) : 10 HNO_(3) + I_(2) rarr 2HIO_(3) + 10 NO_(2)`

Discussion

30232.	The hardest compound of boron is :
Answer» BORON NITRIDE Boron HYDROXIDE Boron carbide Boron oxide. Answer :C

Discussion

30233.	Which halogen has highest value of electron gain enthalpy?
Answer» SOLUTION :CHLORINES

Discussion

30234.	The halogen with the highest value of electron gain enthalpy is..................
Answer» SOLUTION :CHLORINES

Discussion

30235.	The halogen with the highest heat of vaporisation is :
Answer» `F_(2)`<BR>`Cl_(2)` `Br_(2)` `I_(2)`. ANSWER :D

Discussion

30236.	The halogen with highest polarisibility is.........
Answer» FLUORINE CHLORINE BROMINE Iodine Solution :Iodine is LARGEST in size among fluorine, chlorine and bromine.

Discussion

30237.	The halogen with the highest electron affinity is :
Answer» `F`<BR>`CL` `Br` `I.` ANSWER :B

Discussion

30238.	The halogen with highest ionisation potential is
Answer» F Cl Br I Answer :A

Discussion

30239.	The halogen which normally does not form oxoacid is .............. .
Answer» SOLUTION :FLUORINE

Discussion

30240.	The halogen which is solid at room temperature:
Answer» F Cl Br I Answer :D

Discussion

30241.	The halogen which is most easily reduced is :
Answer» `F_(2)` `Cl_(2)` `Br_(2)` `I_(2)` Solution :`F_(2)` is most easily reduced because HF is the most stable ACID AMONG the HALOGEN acid.

Discussion

30242.	The halogen which is most reactive in the halogenation of alkenes under sunlight is
Answer» Chlorine Bromine Iodine All equal Solution :`C_2H_4+Cl_2underset"hv"overset(C Cl_4)to UNDERSET"Ethelene CHLORIDE"(Cl-CH_2-CH_2-Cl)`

Discussion

30243.	The Halogen which has the highest electron affinity :
Answer» Fluorine Chlorine Bromine Iodine Answer :B

Discussion

30244.	The halogen which gives O_2 with hot conc. NaOH is
Answer» `I_2` `Br_2` `Cl_2` `F_2` SOLUTION :Only `F_2` GIVES `O_2` with HOT CONC. NAOH `4NaOH + 2F_2 to 2NaF + 2H_2O + O_2`

Discussion

30245.	The halogen whichforms maximum number of interhalogen compounds is
Answer» `F_(2)`<BR>`Cl_(2)` `Br_(2)` `I_(2)` Solution :FLUORINE has more electronegtive hence it cane form no. of INTER HALOGEN compounds

Discussion

30246.	The halogen that undergoes sublimation is
Answer» `F_(2)` <BR>`Cl_(2)` `Br_(2)` `I_(2)` ANSWER :D

Discussion

30247.	Which shows same oxidation state in all its compounds with other elements :
Answer» Hydrogen Fluorine Carbon Oxygen Answer :B

Discussion

30248.	The halogen that oxidises water
Answer» `F_(2)` `Cl_(2)` `Br_(2) ` `I_(2)` Solution :`F_(2) + 3H_(2) O rarr 2H_(3) O_(2)^(+) + 2F^(-) + ( 1)/( 2) O _(2) , F_(2)^(0) rarr F^(-1)`

Discussion

30249.	The halogen that occurs in liquid state at 25^(@)C
Answer» `Cl_(2)`<BR>`Br_(2)` `F_(2)` `I_(2)` SOLUTION :`Br_(2)` exhibitliquid state.

Discussion

30250.	The halogen that is most readily reduced is:
Answer» Chlorine Bromine Iodine Fluorine Answer :D

Discussion

Explore topic-wise InterviewSolutions in .

Theheat liberated when 1.89 g of benzoic acid burnt in a bomb calorimeter at 25^(@)C increases the temperature of 18.94 kg of water by 0.632^(@)C. If the specific heat of water at 25^(@)C is 0.998cal/g-deg, the value of the heat combustion of benzoic acid is

The heat liberated when 1.89 g of benzoic acid is burnt in a bomb calorimeter at 25^@C increase the temperature of 18.94 kg of water by 0.632^@C. If the specific heat of water at 25^@C is 0.998 cal/g-deg, the value of the heat of combustion of benzoic acid is

The heat evolved in the combustion of benzene is given by: C_(6)H_(6)(l) + 7(1/2)O_(2)(g) to 3H_(2)(l) + 6CO_(2)(g) , DeltaH = -781.0 kcal//"mol"^(-1), When 156 g of C_(6)H_(6) is burnt in an open container, the amount of heat energy released will be:

The heat evolved in the combustion of benzene is given by C_(6)H_(6)+7(1)/(2)O_(2)rarr6CO_(2)(g)+3H_(2)O(l),DeltaH=-3264.6 kJWhich of the following quantities of heat energy will be evolved when 39_(g)C_(6)H_(6) are burnt

The heat evolved in the combustion of benzene is given by C_(6)H_(6)(l) + 7 (1/2)O_(2)(g) to 3H_(2)O(l) + 6CO_(2)(g), DeltaH = -781.0 kcal//"mol"^(-1) When 156 g of C_(6)H_(6) is burnt in an open container, the amount of heat energy released will be

The heat evolved in the combustion of112 litre of water gas (mixture of equal volume of H_(2) and CO) is H_(2)(g) + 1/2O_(2)(g) to H_(2)O(g), DeltaH=-241.8 kJ CO(g) + 1/2O_(2)(g) to CO_(2)(g), DeltaH=-283 kJ

The heat evolved during the combustion of 112 litre of water gas (mixture of equal volume of H_2 and CO) is :GivenH2​ (g)+1/2O2​ (g)=H2​ O(g);ΔH=−241.8kJCO(g)+1/2O2​ (g)=CO2​ (g);ΔH=−283kJ

The heat evolved during the combination of 24 g C and 128 g S following the change isC+S_(2)rarrCS_(2),DeltaH=22.0 kcal

The heat evolved during neutralisation is maximum in the reaction of:

The heat content of a system is called

The heat change in a chemical reaction at constant pressure is:

The heat change taking place during the reaction H_2O(l)rarrH_2O(g) is ?[ Given triangleH_1=H_2O(g)=-57 kal, TriangleH_f=H_2O(l)=-68.3kcal]:

The heat change for the reaction. CO + (1)/(2) O_(2) rarr CO_(2) is called

The heat change for the following reaction at 298K and at constant pressure is +7.3 kcal A_(2)B(s) rarr 2A(s) + 1//2 B_(2)(g), DeltaH =+7.3 kcal The heat change at constant volume would be C(s)+2S(s)rarrCS_(2)(l) is known as

The heat change for the following reaction at 298K and at constant pressure is +7.3 kcal A_(2)B(s) rarr 2A(s) + 1//2 B_(2)(g), DeltaH =+7.3 kcal The heat change at constant volume would be

The heat change DeltaH for the reaction 2CO+O_(2)rarr2CO_(2),DeltaH=-135 kcal is called

The heat change at constant volume (q_(v)) is equal to

The heat capacity of liquid water is 75.6 J/mol K, while the enthalpy of fusion of ice is 6.0 kJ/mol. What is the smallest number of ice cubes at 0^(@)C, each containing 9.0g of water, needed to cool 500 g of liquid water from 20^(@)C to 0^(@)C ?

Theheat capcity of liquildwater is 75.6 J //mol .K, while theenthalpy of fusion of ice is6.0 kJ//mol, What is the smallestnumberof icecubes at0^(@) C,eachcontainig9.0g of water ,needed to cool500 gofliquildwaterfromj 20^(@)to 0^(@) C ?

The heat capacity at constant volume of an ideal gas consisting of monatomic molecules is 3//2 R ( where R is the gas constant ) . The heat capacity at constant pressure is :

The hcp and ccp structure of a given element. (Given radius of element id same in both structures)

The h.c.p. and c.c.p. structures for a given crystal system of equal - sized spheres are expected to have

The HCC bond angle in acetylene is:

The hardness of water is estimated by:

The hardness of metal increases with increase in number of …… involved in metallic bonding.

The hardness Cr is due to ….And metallic lusture is due to

The hardest substance amongst the following is

The hardest substance amonts the following is

The hard plastic covers of telephones are made of polymers of

The halogens, which is attacked by conc. HNO_(3) are :

The hardest compound of boron is :

Which halogen has highest value of electron gain enthalpy?

The halogen with the highest value of electron gain enthalpy is..................

The halogen with the highest heat of vaporisation is :

The halogen with highest polarisibility is.........

The halogen with the highest electron affinity is :

The halogen with highest ionisation potential is

The halogen which normally does not form oxoacid is .............. .

The halogen which is solid at room temperature:

The halogen which is most easily reduced is :

The halogen which is most reactive in the halogenation of alkenes under sunlight is

The Halogen which has the highest electron affinity :

The halogen which gives O_2 with hot conc. NaOH is

The halogen whichforms maximum number of interhalogen compounds is

The halogen that undergoes sublimation is

Which shows same oxidation state in all its compounds with other elements :

The halogen that oxidises water

The halogen that occurs in liquid state at 25^(@)C

The halogen that is most readily reduced is:

The heat evolved during the combustion of 112 litre of water gas (mixture of equal volume of H_2 and CO) is :GivenH2 (g)+1/2O2 (g)=H2 O(g);ΔH=−241.8kJCO(g)+1/2O2 (g)=CO2 (g);ΔH=−283kJ