94420 + Interview Questions in Chemistry in Class 12 Page 604 InterviewSolution

30151.	The heat of neutralisation of a strong base and a strong acid is 13.7 kcal. The heat released when 0.6 mole HCl solution is added to 0.25 mole of NaOH is
Answer» 3.425 kcal 8.22 kcal 11.645 kcal 13.7 kcal Solution :For the neutralisation between a strong acid and a strong base, equal number of moles of `H^+`(from acid) and OH (from base) come out. For ONE mole of such, following equation can be DRAWN: So, 0.25 mole of `H_2O`is produced. ` therefore `Heat RELEASED = `(0.25 xx 13.7) = 3.425 kcal`

Discussion

30152.	The heat of neutralisation of a strong acid and a strong alkali is 57.0 kJ mol^(-1). The heat released when 0.5 mole of HNO_(3) solution is mixed with 0.2 mole o KOH is
Answer» 57.0 kJ 11.4 kJ 28.5 kJ 34.9 kJ Solution :0.2 mole of KOH will NEUTRALISE 0.5 mole of `HNO_(3)` `THEREFORE`HEAT evolved`=57xx0.2=11.4kJ`

Discussion

30153.	Heat of neutralisation of a strong acid by a strong base is equal to DeltaH of
Answer» `H^(+)+OH^(-)=H_(2)O` `H_(2)O+H^(+)=H_(3)O^(+)` `2H_(2)+O_(2)=2H_(2)O` `CH_(3)COOH+NaOH=CH_(3)COONa+H_(2)O` Answer :A

Discussion

30154.	The heat of neutralisation of a strong acid and a strong alkali is 57.0 kJ mol^(-1). The heat releaed when 0.5 mole of HNO_(3) solution is mixed with 0.20 mole of KOH solution is
Answer» 57.0 kJ 11.4 kJ 28.5 kJ 34.9 kJ Solution :NaOH is the LIMITING REACTANT and the enthalpy of neutralisation is to be CALCULATED for 0.2 mole of NaOH and 0.2 mole of `HNO_(3)` as `5.70xx0.2=11.4kJ`

Discussion

30155.	The heat of neutralisation is highest for the reaction between
Answer» `NH_(4)OH-CH_(3)COOH` `HNO_(3)-NH_(4)OH` `NaOH-CH_(3)COOH` `HCl-NaOH` Solution :Heat of neutralisation of strong acid by strong BASE is always greater than the heat of neutralisation of weak acid or weak base because some energy is USED to ionise weak acid or weak base. (a) `underset("weak base-weak acid")(NH_(4)OH-CH_(3)COOH)` (b) `underset("Strong acid-weak base")(HNO_(3)-NH_(4)OH)` (c) `underset("strong base-weak acid")(NaOH-CH_(3)COOH)` (d) `underset("strong acid-strong base")(HCl-NaOH)` `because`HCl is a strong acid and NaOH is a strong base. `therefore` Their heat of neutralisation will be highest among the given.

Discussion

30156.	The heat of fusion is 334.7Jg^(-1). The entropy change in JK^(-1)kg^(-1) in melting of 1 g of ice at 0^(@)C is
Answer» 1.226 0.293 293 1226 Answer :D

Discussion

30157.	The heat of formation of water is 260 kJ. How much H_(2)O is decomposed by 130 kJ of heat?
Answer» 0.25 mol 1 mol 0.5 mol 2 mol Solution :The REACTION for the formation of water is as `H_(2)+(1)/(2)O_(2) to H_(2)O,DeltaH=260kJ`. . (i) On reversing Eq. (i), we get `underset(1mol)(H_(2)O) to H_(2)+(1)/(2)O_(2),DeltaH=-260kJ`. . (ii) `because` By 260 kJ heat, water decomposed=1 mol `therefore `130 kJ heat will decompose water`=(1xx130)/(260)=0.5`mol

Discussion

30158.	The heat of formation of methane is -17.9 kcal. If the heats of atomisation of carbon and hydrogen are 170.9 and 52.1 kcal per mole, Calculate the C-H bond energy in methane.
Answer» Solution :GIVEN that `C(s)+2H_(2)(g) to CH_(4)(g)`, `DeltaH=-17.9kcal` Energy change in reactants Heat of atomisation of 1 mole of C `=170.9` KCAL Heat of atomisation of 4 moles of H `=4xx52.1` kcal Energy change in product Heat of formation of 4 moles of C-H bonds `=4xx x `kcal (where x is the energy of formation of C-H bonds in kcal/mole. ) Since the ALGEBRAIC sum of all the heat changes in equal to the heat of formation of the above given equation, we have `170.9+4xx52.1+4x=-17.9`, `x=-99.3` kcal Thus the bond energy `=+99.3` kcal/mole

Discussion

30159.	The heat of formation of methane C(s)+2H_(2)(g)rarrCH_(4)(g) at constant pressure is 18500 cal at 25^(@)C. The heat of reaction at constant volume would be
Answer» 17904 CAL 18202 cal 18798 cal 19096 cal SOLUTION :`DeltaH=18500=DELTAE+DeltanRT` or 18500 = `DeltaE+(-1)xx2xx298=19096 cal`.

Discussion

30160.	The heat of formation of methane C(s)+2H_2(g)rarrCH_4(g) at constant is 18500 cal at 25^@C. The heat of reaction at constant volume would be:
Answer» 19096 cal 18798 cal 18202 cal 17904 cal Answer :A

Discussion

30161.	The heat of formation of H_(2)O(l) is - 68.0 kcal, the heat of formation of H_(2)O(g) is likely to be
Answer» `- 68.0` kcal `- 67.4` kcal 80.0 kcal `- 58.3` kcal Solution :When `H_(2)O_((L))` is convert to form `H_(2)O_((G))`, HEAT is absorbed hence `DeltaH_(1) gt DeltaH_(2)`.

Discussion

30162.	The heat of formation of HCl (g) from the reaction H_(2)(g)+Cl_(2)(g)=2HCl(g),DeltaH=-44kcal is
Answer» `+44 KCAL` `-44 kcal` `+22 kcal` `-22 kcal` ANSWER :D

Discussion

30163.	The heat of formation of Fe_(2)O_(3) is -824.2 kJ mol^(-1). Delta H for the reaction 2Fe_(2)O_(3)(s)rarr 4Fe(s)+3O_(2)(g)is :
Answer» `-412.1`KJ `-1648.4` kJ `-3296.8`kJ `1648.4`kJ ANSWER :D

Discussion

30164.	The heat of formation of Fe_(2)O_(3) "is" -821.32 kJ "mole"^(-1) at 298 K and 1 atm and that of Al_(2)O_(3) is -1675.60 kJ"mole"^(-1) under the same condition. Calculate the heat of reaction of reduction of 1 "mole" of Fe_(2)O_(3) with metallic aluminium.
Answer» ANSWER :(-854.28 KJ)

Discussion

30165.	The heat of formation of ethylene is 12.5 kcal. Calculate C=C bond energy in ethaylene from the following data. Heat of atomisation of C=170.9 "kcal/mole",Heat of atomisation of H=52.1 "kcal/mole" bond energy of C-H=99.3 "kcal/mole".
Answer» Solution :Given that, `2C(s)+2H_(2)(g) to C_(2)H_(4)(g) {H-overset(H)overset(\|)(C )=overset(H)overset(\|)-H}` , `DeltaH=12.5` kcal For reactants Heat of atomisation of 2 MOLES of C`=2xx170.9` kcal Heat of atomisation of 4 moles of `H=4xx52.1` kcal For PRODUCTS Heat of formation of 4 moles of C-H BONDS `=-4xx99.3`kcal Heat of formation of 1 mole of C=C bond `=1xx x` [where x is the energy of formation of C=C bond in kcal/mole] Adding up, we get the heat of formation of the reaction given above i.e., `2xx170.9+4xx52.1-4xx99.3+x=12.5` or `x=-140.5` kcal/mole Thus, the bond energy of C=C bond `=+140.5` kcal/mole

Discussion

30166.	The heat of formation of ethane is -20.3 kcal. Calculate the bond energy of C-C bond in ethane if the heats of atomisation of carbon and hydrogen are respectively 170.9 and 52.1 kcal per mole and bond energy of C-H bond is 99.0 kcal.
Answer» ANSWER :(80.7 KCAL)

Discussion

30167.	The heat of formation of CO(g) and CO_(2)(g) are -26.4 kcal and -94.0 kcal respectively. The heat of of combustion of carbon monoxide will be
Answer» `+26.4` kcal `-67.6` kcal `-120.6` kcal `+52.8 kcal Solution :AIM:`CO+(1)/(2)O_(2)rarrCO_(2)` `DELTAH=DeltaH_(F)^(@)(CO_(2))-[DeltaH_(f)^(@)(CO)+(1)/(2)DeltaH_(f)^(@)(O_(2))]` `=-94.0-(-26.4)=-67.6 kcal`.

Discussion

30168.	The heat of formation of CO(g) and CO_2(g) are -26.4 kcal and -94.0 kcal respectively. Heat of combustion of carbon monoxide will be:
Answer» `+26.4 KCAL` `-67.6 kcal` `-120.6 kcal` `+52.8 kcal` ANSWER :B

Discussion

30169.	The heat of formation is the change in enthalpy accompanying the formation of a substance from its elements at 298 K and 1 atm pressure. Since the enthalpies of elements are taken to be zero, the heat of formation (DeltaH) of compounds
Answer» Is ALWAYS NEGATIVE Is always positive May be negative or positive Is zero Answer :C

Discussion

30170.	The heat of Fe_2O_3formation from simple substances is -821.32 kJ/mole at 298 K and standard pressure, and that of Al_2O_3formation is -1675.60 kJ/mole under the same conditions. Calculate the heat of reaction of reduction of 1 mole Fe_2O_3with metallic aluminium.
Answer» SOLUTION :`-854.28kJ`

Discussion

30171.	The heat of formation is the change in enthalpy accompanying the formation of a substance fiom its elements at 298 K and 1 atm pressure. Since the anthalpies of elements are taken to be zero, the heat of formation (triangleH) of compounds
Answer» ALWAYS NEGATIVE Is always positive May be negative or positive Answer :C

Discussion

30172.	The heat of combustion of yellow phosphorus and red phosphorus are -9.91 kJ and -8.78 kJ respectively. The heat of transition of yellow phosphorus to red phosphorus is
Answer» `-18.69 KJ` `+ 1.13 kJ` `+18.69 kJ` `-1.13 kJ` ANSWER :D

Discussion

30173.	the heat of combustion ofsoucrose , C_(12)H_(22)O_(11)(s) at constany volume is 1348.9 kcal mol ^(-1) at 25 ^(@) then the heat of reaction at constant pressure when steam is produced is
Answer» `-1348. 9 kcal ` `-1342.34 kcal` `+ 1250 Kcal ` none of these Solution :the COMBUSTION equaion of sucrose is `C_(12)H_(22)O_(11)(s)+120_(2)(g)to12CO_(2)(g)+11H_(2)O(g)` here , `DELTAH=12 + 11 -12=11` As we know `DeltaH=DeltaE= + DeltanRT` `DeltaH=(- 1348.9 xx10^(3))+ 11xx2xx298=-1342.34 kcal`

Discussion

30174.	The heat of combustion of sucrose, C_(12)H_(22)O_(11)(s) at constant volume is - 1348.9 kcal mol^(-1) at 25^(@)C then the heat of reaction at constant pressure, when stem is produced, is
Answer» Solution :The combustion equation of sucrode is `C_(12)H_(22)O_(11)(S)+12O_(2)(g) RARR 12CO_(2)(g)+11H(2)O(g)` Here, `Deltan_(g)=` sum of gaseous product moles-sum of gaseous reactant moles `Deltan_(g)=11` `DeltaH=DeltaE+Deltan_(g)RT`, Here, `DeltaE=-1348.9 kcal` `R=2.0 cal, T=25+273=299 K` `:. DeltaH=(-1348.9xx1000)+11xx2xx298` `=-1348900+6556=-1342344 cal` `=-1342. 344 kcal`

Discussion

30175.	The heat of combustion of naphthalene (s) is -123.25 kcal. If the heats of formation of CO_(2)(g) and H_(2)O (l) are -97.0 and -68.4 kcal respectively. Calculate the heat of formation of naphthalene.
Answer» Solution :Given that, (i) `C_(10)H_(8)(s)+12O_(2)(g) to 10CO_(2)(g)+4H_(2)O(l),DeltaH=-123.25"kcal"` (II) `C(s)+O_(2)(g) to CO_(2)(g),DeltaH=-97.0"kcal"` (iii)`H_(2)(g)+(1)/(2)O_(2)(g) to H_(2)O(l),DeltaH=-68.4"kcal"` We have to calculate `DeltaH` of the EQUATION, `10C(s)+4H_(2)(g) to C_(10)H_(8)(s),DeltaH=?` Applying the inspection method, [-Eqn.(i)+10xxEqn. (ii)+4xxEqn.(iii)], we get, `-C_(10)H_(8)(s)-12O_(2)(g)+10C(s)+10O_(2)(g)+4H_(2)(g)+2O_(2)(g) to -10CO_(2)(g)-4H_(2)O(l)+10CO_(2)(g)+4H_(2)O(l),DeltaH=-(-123.25)+10xx(-97.0)+4xx(-68.4)` or `10C(s)+4H_(2)(g) to C_(10)H_(8)(s),DeltaH=-1120.35"kcal"`

Discussion

30176.	The heat of combustion of rhombic and momoclinic sulphur are 70.96 and 71.03 kcal. The heat of transition of S_(RrarrM is:
Answer» 70.96 KCAL 71.03 kcal `-70 CAL` `+ 70 cal` ANSWER :D

Discussion

30177.	The heat of combustion of methane is, -880kJ mol^-1. If 3.2 g of methane is burnt:
Answer» 176 KJ of HEAT is evolved 176 kJ of heat is absorbed 88 kJ of heat is evolved None of the above Answer :A

Discussion

30178.	The heat of combustion of graphite at 298 K is -393.795 kJ/mole, while that of diamond's combustion at the same temperature is -395.692 kJ/mole. The specific heats for these substances are 720.83 and 505.58 J kg^(-1)K^(-1) respectively. Calculate the heat of graphite's transformation into diamond at 273 K.
Answer» SOLUTION :1.962kJ/mole

Discussion

30179.	The heat of combustion of ethyl alcohol is 330 kcal. If the heats of formation of CO_(2)(g) and H_(2)O(l) are 94.3 and 68.5 kcal respectively, calculate the heat of formation of ethyl alcohol.
Answer» ANSWER :(-64.1 KCAL)

Discussion

30180.	The heat of combustion of ethene gas is 330 Kcal "mol"^(-1) calculate gtc=clt bond energy (in kcal/mol) assuming that bond energy of C-H bond is 93.6 Kcal "mol"^(-1) Given :DeltaH_f^@ for CO_2(g) and H_2O(l) are -94.2 and -61 Kcal "mol"^(-1) respectively.Heat of atomisation of carbon and hydrogen are 150 and 51.5 Kcal "mol"^(-1) respectively.
Answer» Solution :`CH_2=CH_2(g)+3O_2(g)to2CO_2(g)+2H_2O(L)` `:.-330=[2XX(94.2)+2(-61)]-[DeltaH_f^@C_2H_4]:.DeltaH_f^@(C_2H_4)=19.6 Kcal mol^(-1)` `:. 2C(s)+2H_2(g)toCH_2=CH_2(g),DeltaH_f=19.6` `because DeltaH_("Reaction")=2DeltaH_("ATM" ( C))+4DeltaH_("atm"(H))-4B.E._((C=C))` 19.6=2x150+4x51.5-4x93.6-`B.E._((C=C))` `B.E._((C=C))=112` Kcal/mol

Discussion

30181.	The heat of combustion of ethanol was determined in a bomb calorimeter and was found to be- 670.48 kcal "mol"^(-1) at 25^(@) C. What will be DeltaU for the same reaction at 298 K?
Answer» `-335.24` kcal `-669.28` CAL `-670.48` kcal `-280.26 XX 10^(4)` J Answer :C::D

Discussion

30182.	The heat of combustion of CH_(4(g)),C_(("graphite")) and H_(2(g)) are 20 kcal, -40kcal and -10 kcal respectively. The heat of formation of methane is
Answer» `-4.0` kcal `+40` kcal `-80` kcal `+80` kcal Solution :Given, (i)`CH_(4)+2O_(2)rarrCO_(2)+2H_(2)O, DeltaH=+20 kcal` (ii)`C+O_(2)rarrCO_(2), DeltaH=-40 kcal` `(III) H_(2)+(1)/(2)O_(2)rarrH_(2)O, DeltaH=-10 kcal` AIM:`C+2H_(2)rarrCH_(4)` `(ii) +2xx"(iii)-(i) gives"` `DeltaH=-40+2(-10)-(+20)=-80 kcal`.

Discussion

30183.	The heat of combustion of ethanol determined by a bomb calorimeter is -670.48 kcalmol^-1 at 25^@C. What is triangleU at 25^@C for the reaction, C_2H_5OH(l)+3 O_2(g)rarr2CO_2+3H2O(g) is:
Answer» `-335.24 KCAL` `-669.28 kcal` `-670.48 kcal` `+670.48 kcal` ANSWER :C

Discussion

30184.	The heat of combustion of CH_(4)(g), C(graphite) and H_(2)(g) are - 20 Kcal, - 40 Kcal and -10 Kcal respectively. The heat of formation of methane is
Answer» `-40` KCAL `+40` Kcal `-80` Kcal `+80` Kcal ANSWER :A

Discussion

30185.	The heat of combustion of carbon to CO_(2) is -393.5 kJ/mol. The heat released upon formation of 35.2 g of CO_(2) from carbon and oxygen gas is
Answer» `+315` KJ `-31.5` kJ `-315` kJ `+31.5` kJ Solution :`C+O_(2)rarrCO_(2)DeltaH=-393.5 kJ//mol` `because` 44gm of `CO_(2)` FORM by which heat RELEASED `=-393.5 kJ` `therefore` 1 gm of `CO_(2)` form by which heat released = `-(393.5)/(44)` `therefore` 35.2 gm (given) of `CO_(2)` form by which heat released `=-(393.5)/(44)xx35.2=-315 kJ`.

Discussion

30186.	The heat of combustion of carbon is -393.5kJ//mol. The heat released upon the formation of 35.2 g of CO_(2) from carbon and oxygen gas is
Answer» `+135` kJ `-31.5` kJ `-315` kJ `+31.5` kJ Solution :`C+O_(2)to CO_(2)` `DeltaH=-393.5kJ` `THEREFORE` Heat RELEASED UPON the formation of 1 g of `CO_(2)=(-393.5)/(44)kJ` `therefore` Heat released upon the formation of 1 g of `CO_(2)=(-393.5)/(44)xx35.2` `~~-315kJ`

Discussion

30187.	the heat of combustion of carbon to CO_(2) is - 393 . 5 kJ // mol . The heat released upon formation of 35.2g of CO_(2) from carbon and oxygen gas is
Answer» `+ 315 KJ` `-31 . 5kJ` `-315 kJ` `+ 31.5KJ` Solution :`C+O_(2)toCO_(2), DeltaH=-393.5kJ//mol` HEAT releaded during the formation of 35.2 G(GIVEN) of `CO_(2)=-(393.5xx35.2)/44=-315 kJ`

Discussion

30188.	The heat of combustion of carbon is -94 kcal at 1 atm pressure. The intrinsic energy of CO_(2) is
Answer» `+94` kcal `-94` kcal `+47` kcal `-47` kcal Solution :`C_((S))+O_(2)(g)rarrCO_(2(g)), Deltan_(g)=1-1=0` `THEREFORE DeltaE=DeltaH=-94 kcal` `DeltaE=E_(CO_(2))-(E_(C)+E_(O_(2)))=E_(CO_(2))-(0+0)` `or E_(CO_(2))=DeltaE=-94 kcal`.

Discussion

30189.	The heat of combustion of carbon is -393.5 kJ/mol. The heat released upon thee formation of 35.2 g off CO_(2) from, carbon and oxygen gas is
Answer» `+315kJ` `-31.5kJ` `-315kJ` `+31.5kJ` Solution :`C+O_(2) to CO_(2),DeltaH=-393.5kJ//mol` `therefore`Heat released upon the formation of 44 G of `CO_(2)` LTBRGT `=-393.5kJ` `therefore`Heat released upon the formation of 1 g of `CO_(2)` `=(-393.5)/(44)kJ` `therefore`Heat released upon the formation of 35.2 g of `CO_(2)` `=(-393.5)/(44)xx35.2=-315kJ`

Discussion

30190.	the heat of combustion of benzene determined in a bomb calorimeter is- 870 kcal mol ^(-1) at 298 K. The value of delta E for reaction is
Answer» ` -1740 KCAL MOL ^(-1)` ` + 870 kcal mol ^(-1)` ` - 32 . 64 kcal mol ^(-1)` `+ 1740 kcal mol ^(-1)` Solution :the heat CHANGE determined ina BOMB colorimeteris `DeltaE`,VALUE thus , `DeltaE=-870 kcal mol ^(-1)`

Discussion

30191.	The heat of combustion of benzene determined in a bomb calorimeter is - 870 kcal mol^(-1) at 25^(@)C. The value of DeltaE for the reaction is
Answer» `-1740` KCAL `-870` kcal `-872` kcal `-874` kcal Answer :B

Discussion

30192.	The heat of combustion of a compound
Answer» is ALWAYS POSITIVE is always NEGATIVE may be positive or negative is ZERO at any STAGE of the reaction Solution :is always negative

Discussion

30193.	The heat of combustion for C ,H_2 and CH_4 are-349.0, -241.8 and -906.7 kJ respectively.The heat of formation CH_4 is:
Answer» 174.1 kJ 274 kJ 374.1 KJ 74.1 kJ Answer :D

Discussion

30194.	the heat of atomosaton pf P_(4)H_(4)(g)and PH_(3) (g) are 355kcal / mol and 228 kcal/ mol respectively . The energy of P----P bond is
Answer» `102 KCAL mol ^(-1)` `51kcal mol ^(-1)` `26 kcal mol ^(-1)` `204 kcal mol ^(-1)` SOLUTION :P ----- H bood energy `=228/3=76 kcal mol^(-1) for P_(4)H_(4)` bond energy fo `4(P----H)+(P-----P)` ` 355 kcal mol^(-1)``4xx 76 + (P--P)=355 kcal mol^(-1)` (P---P) bond energy = `51 kcal mol^(-1)`

Discussion

30195.	The heat of atomization of PH_(3)(g) is 228 k cal mol^(-1) and that of P_(2)H_(4)(g) is 355 k cal mol^(-1). The energy of the P-P bond is
Answer» 102 K cal `mol^(-1)` 51 k cal `mol^(-1)` 26 k cal `mol^(-1)` 204 k cal `mol^(-1)` Solution :Bond dissociation energy of `PH_(3)(g)` = 228 k cal `mol^(-1)` F - H bond energy `=(228)/(3)=76 " k cal mol"^(-1)` Bond energy of 4(P-H)+(P-P) `=355 k cal mol^(-1)` or `4xx76+(P-P)=355k cal mol^(-1)implies51 k cal mol^(-1)`

Discussion

30196.	The heat of atomisation of PH_(3)(g) is 228 kcal perr mol annd that of P_(2)H_(4)(g) is 335 kcal per mol. The energy of P-P bond is
Answer» 102 kcal/mol 31 kcal/mol 26 kcal/mol 204 kcal/mol Answer :D

Discussion

30197.	The heat of atomisation of methane and ethene are 360 kJ/mol and 620 kJ/mol, respectively. The longest wavelenth of light capable of breaking the C-C bond is (Avogadro number =6.02xx10^(23),h=6.62xx10^(-34) Js)
Answer» `2.48xx10^(3)NM` `1.49xx10^(3)nm` `2.49xx10^(5)nm` `2.48xx10^(4)nm` Solution :`4BE(C_H)` BOND =360kJ/mol `BE(C-H)` bond =90kJ/mol In `C_(2)H_(6)implies BE_((C-C))+6BE_((C-H))=620kJ//mol` `BE_((C-C))` bond`=620-6xx90=80kJ//mol` `lamda` for RUPTURE of `C-C` bond `=(6.262xx3xx10^(8))/(80xx10^(3))` `=2.48475xx10^(4)nm`

Discussion

30198.	The heat of a chemical reaction is given by the following expression, ______ .
Answer» `DELTA H=Sigma H_R-Sigma H_P` `Delta H=Sigma H_R` `Delta H=Sigma H_P-Sigma H_R` `Delta H=Sigma H_P` ANSWER :C

Discussion

30199.	The heat measured for a reaction in a bomd calorimeter is:
Answer» `TRIANGLEG` `TRIANGLEH` `TRIANGLEU` `PtriangleV` ANSWER :C

Discussion

30200.	The heat measured for a reaction in a bomb calorimeter is
Answer» `DELTA G` `Delta H` `Delta E` `P Delta V` Solution :In bomb calorimeter, REACTION is made at constant VOLUME, i.e., `DeltaV` = 0 thus HEAT measured is `Delta E`

Discussion

Explore topic-wise InterviewSolutions in .

The heat of neutralisation of a strong base and a strong acid is 13.7 kcal. The heat released when 0.6 mole HCl solution is added to 0.25 mole of NaOH is

The heat of neutralisation of a strong acid and a strong alkali is 57.0 kJ mol^(-1). The heat released when 0.5 mole of HNO_(3) solution is mixed with 0.2 mole o KOH is

Heat of neutralisation of a strong acid by a strong base is equal to DeltaH of

The heat of neutralisation of a strong acid and a strong alkali is 57.0 kJ mol^(-1). The heat releaed when 0.5 mole of HNO_(3) solution is mixed with 0.20 mole of KOH solution is

The heat of neutralisation is highest for the reaction between

The heat of fusion is 334.7Jg^(-1). The entropy change in JK^(-1)kg^(-1) in melting of 1 g of ice at 0^(@)C is

The heat of formation of water is 260 kJ. How much H_(2)O is decomposed by 130 kJ of heat?

The heat of formation of methane is -17.9 kcal. If the heats of atomisation of carbon and hydrogen are 170.9 and 52.1 kcal per mole, Calculate the C-H bond energy in methane.

The heat of formation of methane C(s)+2H_(2)(g)rarrCH_(4)(g) at constant pressure is 18500 cal at 25^(@)C. The heat of reaction at constant volume would be

The heat of formation of methane C(s)+2H_2(g)rarrCH_4(g) at constant is 18500 cal at 25^@C. The heat of reaction at constant volume would be:

The heat of formation of H_(2)O(l) is - 68.0 kcal, the heat of formation of H_(2)O(g) is likely to be

The heat of formation of HCl (g) from the reaction H_(2)(g)+Cl_(2)(g)=2HCl(g),DeltaH=-44kcal is

The heat of formation of Fe_(2)O_(3) is -824.2 kJ mol^(-1). Delta H for the reaction 2Fe_(2)O_(3)(s)rarr 4Fe(s)+3O_(2)(g)is :

The heat of formation of Fe_(2)O_(3) "is" -821.32 kJ "mole"^(-1) at 298 K and 1 atm and that of Al_(2)O_(3) is -1675.60 kJ"mole"^(-1) under the same condition. Calculate the heat of reaction of reduction of 1 "mole" of Fe_(2)O_(3) with metallic aluminium.

The heat of formation of ethylene is 12.5 kcal. Calculate C=C bond energy in ethaylene from the following data. Heat of atomisation of C=170.9 "kcal/mole",Heat of atomisation of H=52.1 "kcal/mole" bond energy of C-H=99.3 "kcal/mole".

The heat of formation of ethane is -20.3 kcal. Calculate the bond energy of C-C bond in ethane if the heats of atomisation of carbon and hydrogen are respectively 170.9 and 52.1 kcal per mole and bond energy of C-H bond is 99.0 kcal.

The heat of formation of CO(g) and CO_(2)(g) are -26.4 kcal and -94.0 kcal respectively. The heat of of combustion of carbon monoxide will be

The heat of formation of CO(g) and CO_2(g) are -26.4 kcal and -94.0 kcal respectively. Heat of combustion of carbon monoxide will be:

The heat of formation is the change in enthalpy accompanying the formation of a substance from its elements at 298 K and 1 atm pressure. Since the enthalpies of elements are taken to be zero, the heat of formation (DeltaH) of compounds

The heat of Fe_2O_3formation from simple substances is -821.32 kJ/mole at 298 K and standard pressure, and that of Al_2O_3formation is -1675.60 kJ/mole under the same conditions. Calculate the heat of reaction of reduction of 1 mole Fe_2O_3with metallic aluminium.

The heat of formation is the change in enthalpy accompanying the formation of a substance fiom its elements at 298 K and 1 atm pressure. Since the anthalpies of elements are taken to be zero, the heat of formation (triangleH) of compounds

The heat of combustion of yellow phosphorus and red phosphorus are -9.91 kJ and -8.78 kJ respectively. The heat of transition of yellow phosphorus to red phosphorus is

the heat of combustion ofsoucrose , C_(12)H_(22)O_(11)(s) at constany volume is 1348.9 kcal mol ^(-1) at 25 ^(@) then the heat of reaction at constant pressure when steam is produced is

The heat of combustion of sucrose, C_(12)H_(22)O_(11)(s) at constant volume is - 1348.9 kcal mol^(-1) at 25^(@)C then the heat of reaction at constant pressure, when stem is produced, is

The heat of combustion of naphthalene (s) is -123.25 kcal. If the heats of formation of CO_(2)(g) and H_(2)O (l) are -97.0 and -68.4 kcal respectively. Calculate the heat of formation of naphthalene.

The heat of combustion of rhombic and momoclinic sulphur are 70.96 and 71.03 kcal. The heat of transition of S_(RrarrM is:

The heat of combustion of methane is, -880kJ mol^-1. If 3.2 g of methane is burnt:

The heat of combustion of ethyl alcohol is 330 kcal. If the heats of formation of CO_(2)(g) and H_(2)O(l) are 94.3 and 68.5 kcal respectively, calculate the heat of formation of ethyl alcohol.

The heat of combustion of ethanol was determined in a bomb calorimeter and was found to be- 670.48 kcal "mol"^(-1) at 25^(@) C. What will be DeltaU for the same reaction at 298 K?

The heat of combustion of CH_(4(g)),C_(("graphite")) and H_(2(g)) are 20 kcal, -40kcal and -10 kcal respectively. The heat of formation of methane is

The heat of combustion of ethanol determined by a bomb calorimeter is -670.48 kcalmol^-1 at 25^@C. What is triangleU at 25^@C for the reaction, C_2H_5OH(l)+3 O_2(g)rarr2CO_2+3H2O(g) is:

The heat of combustion of CH_(4)(g), C(graphite) and H_(2)(g) are - 20 Kcal, - 40 Kcal and -10 Kcal respectively. The heat of formation of methane is

The heat of combustion of carbon to CO_(2) is -393.5 kJ/mol. The heat released upon formation of 35.2 g of CO_(2) from carbon and oxygen gas is

The heat of combustion of carbon is -393.5kJ//mol. The heat released upon the formation of 35.2 g of CO_(2) from carbon and oxygen gas is

the heat of combustion of carbon to CO_(2) is - 393 . 5 kJ // mol . The heat released upon formation of 35.2g of CO_(2) from carbon and oxygen gas is

The heat of combustion of carbon is -94 kcal at 1 atm pressure. The intrinsic energy of CO_(2) is

The heat of combustion of carbon is -393.5 kJ/mol. The heat released upon thee formation of 35.2 g off CO_(2) from, carbon and oxygen gas is

the heat of combustion of benzene determined in a bomb calorimeter is- 870 kcal mol ^(-1) at 298 K. The value of delta E for reaction is

The heat of combustion of benzene determined in a bomb calorimeter is - 870 kcal mol^(-1) at 25^(@)C. The value of DeltaE for the reaction is

The heat of combustion of a compound

The heat of combustion for C ,H_2 and CH_4 are-349.0, -241.8 and -906.7 kJ respectively.The heat of formation CH_4 is:

the heat of atomosaton pf P_(4)H_(4)(g)and PH_(3) (g) are 355kcal / mol and 228 kcal/ mol respectively . The energy of P----P bond is

The heat of atomization of PH_(3)(g) is 228 k cal mol^(-1) and that of P_(2)H_(4)(g) is 355 k cal mol^(-1). The energy of the P-P bond is

The heat of atomisation of PH_(3)(g) is 228 kcal perr mol annd that of P_(2)H_(4)(g) is 335 kcal per mol. The energy of P-P bond is

The heat of atomisation of methane and ethene are 360 kJ/mol and 620 kJ/mol, respectively. The longest wavelenth of light capable of breaking the C-C bond is (Avogadro number =6.02xx10^(23),h=6.62xx10^(-34) Js)

The heat of a chemical reaction is given by the following expression, ______ .

The heat measured for a reaction in a bomd calorimeter is:

The heat measured for a reaction in a bomb calorimeter is