Explore topic-wise InterviewSolutions in .

This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.

501.

Which process requires the greatest amount of energy for 1 mole of `H_(2)O`?A. Breaking the o-H bondsB. MeltingC. EvaporatingD. Subliming

Answer» Correct Answer - a
Discussion
502.

If the circles represent molecules , which diagram provides the best molecular level representation of a pure solid in the process of melting?A. B. C. D.

Answer» Correct Answer - b
Discussion
503.

A system undergoes a process in which `DeltaU = + 300 J` while absorbing 400 J of heat energy and undergoing an expansion against 0.5 bar. What is the change in the volume (in L)?A. 4B. 5C. 2D. 3

Answer» Correct Answer - C
`DeltaU=q+w`
`300 = 400 -0.5 xxDeltaVxx100`
`DeltaV = 2L`
Discussion
504.

Calculate `Delta_(f)H^(@)` (in kJ/mol) for `Cr_(2)O_(3)` from the `Delta_(r)G^(@)` and the `S^(@)` values provided at `27^(@)` `4Cr(s)+3O_(2)(g)rarr2Cr_(2)O_(3)(s)," "Delta_(r)G^(@)=-2093.4kJ//mol` `S^(@)("J//K mol") : S^(@)(Cr,s)=24," "S^(@)(O_(2),g)=205," "S^(@)(Cr_(2)O_(3),s)=81`A. `-2258.1 kJ//mol`B. `-1129.05 kJ//mol`C. `-964.35 kJ//mol`D. `3462kJ//mol`

Answer» Correct Answer - B
`Delta_(r)G^(@) = Delta_(r)H^(@)-T xx Delta_(r)S^(@)`
`Delta_(r)S^(@) = 2 xx 81 -4xx 24 -3 xx 205 J//mol`
`:. Delta_(r)H^(@) = -2258.1 kJ//mol`
`Delta_(r)H^(@) = 2 xx Delta_(f)H^(@)(Cr_(2)O_(3), s)`
`:. Delta_(f)H^(@)(Cr_(2)O_(3), s) = -(2258.1)/(2)`
`= -1129.05 kJ//mol`.
Discussion
505.

Calculate standard molar entropy `O_(2)(g)` from the following thermodynamics data at 300 K : `4Cr(s)+3O_(2)(g)to2Cr_(2)O_(3)(s),DeltaG^(@)=-2093.4 " kJ"//mol` `DeltaH_(f)^(@)Cr_(2)O_(3)(s)=-1129.05" kJ"//"mole"` `S_(m)^(@)Cr(s)=24" J"//K" mole"` `S_(m)^(@)Cr_(2)O_(3)(s)=81" J"//K" mole"`

Answer» Correct Answer - B
Discussion
506.

Consider the following reaction `2Fe_(2)O_(3) + 3C(s) to 4Fe(s) + 3Co_(2)(g)` `DeltaH^(@) of Fe_(2)O_(3)` and `CO_(2) are -820kJ//"mol"` and `-390 kJ//"mol"` respectively The reaction respectively .A. endothermicB. exothermicC. spontaneous at high temperatureD. spontancous at low temperature

Answer» Correct Answer - a,c
Discussion
507.

Determine which of the following reactions at constant pressure represents surroundings that do work on the system: I. `4NH_(3)(g)+7O_(2)(g)rarr4NO_(2)(g)+6H_(2)O(g)` II. `CO(g)+2H_(2)(g)rarrCH_(3)OH(l)` III. `C(s,"graphite")+H_(2)O(g)rarrCO(g)+H_(2)(g)` IV. `H_(2)OrarrH_(2)O(l)`A. II,IVB. II and IIIC. II,IVD. I and II,IV

Answer» Correct Answer - D
Discussion
508.

Calculate `Delta_(f)H^(@)` (in kJ/mol) for `Cr_(2)O_(3)` from the `Delta_(r)G^(@)` and the `S^(@)` values provided at `27^(@)` `4Cr(s)+3O_(2)(g)rarr2Cr_(2)O_(3)(s)," "Delta_(r)G^(@)=-2093.4kJ//mol` `S^(@)("J//K mol") : S^(@)(Cr,s)=24," "S^(@)(O_(2),g)=205," "S^(@)(Cr_(2)O_(3),s)=81`A. `-2258.1kJ//mol`B. `-1129.05kJ//mol`C. `-964.35kJ//mol`D. None of these

Answer» Correct Answer - B
`Delta_(r)G^(@)=Delta_(r)H^(@)-TxxDelta_(r)S^(@)`
`Delta_(r)S^(@)=2xx81-4xx24-3xx205J//mol`
`therefore" "Delta_(r)H^(@)=-2258.1 kJ//mol`
`Delta_(r)H^(@)=2xxDelta_(f)H^(@)(Cr_(2)O_(3),s)`
`thereforeDelta_(f)H^(@)(Cr_(2)O_(3),s)=-(2258.1)/(2)`
`=-1129.05"kJ/mol"`
Discussion
509.

A sample of liquid in a thermally insulated constant ( a calorimetre ) is strirred for 2 hr. by a mechancal linkage to motor in the surrounding ,for this procees :A. `wlt0, q=0, DeltaU=0`B. `wgt0, q=0, DeltaUgt0`C. `wlt0,qgt0, DeltaU=0`D. `wgt0,q=0, DeltaUgt0`

Answer» Correct Answer - D
Discussion
510.

A sample of liquid in a thermally insulated constant ( a calorimetre ) is strirred for 2 hr. by a mechancal linkage to motor in the surrounding ,for this procees :A. `w lt 0, q = 0, Delta U = 0`B. `w gt 0, q gt 0, Delta U gt 0`C. `w lt 0, q gt 0, Delta U = 0`D. `w gt 0, q = 0, Delta U gt 0`

Answer» Correct Answer - D
`q=0, " "DeltaU=q+w`
`wgt0 " so "DeltaU gt 0`
Discussion
511.

Determine which of the following reactions at constant pressure represent surrounding that do work on the system environment : (P) `4NH_(3)(g) + 7O_(2)(g) to 4 NO_(2)+ 6H_(2)O(g)` (Q) `CO.O(g)+ 2H_(2)(g) to CH_(3)OH(l)` (R) `C("s,graphite")+H_(2)O(g) to CO(g)+H_(2)(g)` (S) `H_(2)O(s) to H_(2)O(l)`A. III, IVB. II and IIIC. II, IVD. I and II, IV

Answer» Correct Answer - D
`w=-P_("ext").DeltaV=-Deltan_(g)RT" and "Deltan_(g)" is -ve for I and III"`
also `" "DeltaV=-ve " for IV"`
Discussion
512.

Determine `Delta U^(@) ` at 300K for the following reaction using the listed enthalpies of reaction : `4CO(g)+8H_(2)(g)to3CH_(4)(g)+CO_(2)(g)+2H_(2)O(l)` `C("graphite")+(1)/(2)O_(2)(g)to CO(g), DeltaH_(1)^(@)=-110.5KJ`` CO(g)(1)/(2)O_(2)(g)toCO_(2)(g), DeltaH_(2)^(@)=-282.9KJ` `H_(2)(g)+(1)/(2)O_(2)(g)to H_(2)O(l), DeltaH_(3)^(@)=-285.8KJ` `C("graphite")+2H_(2)(g)to CH_(4)(g), DeltaH_(4)^(@)=-74.8KJ`A. `-653.5` kJB. `-686.2` kKJC. `-747.4` kJD. None of these

Answer» Correct Answer - D
`DeltaH^(@)=-3DeltaH_(1)^(@)+DeltaH_(2)^(@)+2DeltaH_(3)^(@)+3DeltaH_(4)^(@)`
`=-747.4kJ`
`DeltaH^(@)=DeltaU^(@)+Deltan_(g)RT," where " Deltan_(g)=-8`
`-747.4=DeltaU^(@)=(8xx8.314xx300)/(1000)`
`DeltaU^(@)=-727.44kJ`
Discussion
513.

Given that `Delta H = 0` for mixing of two gases. Explain whether the diffusion of these gases into each other in a closed container is a spontaneous process or not ?

Answer» The mixing of two gases have `Delta H` equal to zero. Therefore, it is spontaneous process because energy factor has no role to play but randomness increases i.e., randomness factor favours the process.
Discussion
514.

Using listed informations, calculate `Delta_(r)G^(@)` (in kJ/mol) at `27^(@)C` `Co_(3)O_(4)(s)+4CO(g)rarr3Co(s)+4CO_(2)(g)` Given : At 300 K `DeltaH_(f)^(@)(kJ//mol)-891,-110.5,0.0,-393.5` `S^(@)(J//K-mol)102.5, 197.7, 30.0, 213.7`A. `-214.8`B. `-195.0`C. `-200.3`D. -256.45

Answer» Correct Answer - D
`Delta_(r)H^(@)=3.Delta_(f)H^(@)(CO,s)+4Delta_(f)H^(@)(CO_(2),g)`
`-Delta_(f)H^(@)(Co_(3)O_(4),s)-4.Delta_(f)H^(@)(CO,g)`
`Delta_(r)H^(@)=-"241 kJ/mol"`
`Delta_(r)S^(@)=3xx30+4xx213.7-102.5-4xx197.7`
= 51.5 J/K-mol
`therefore" "Delta_(r)G^(@)=Delta_(r)H^(@)-T.Delta_(r)S^(@)`
`=-241-(300xx51.5)/(1000)`
`=-256.45"kJ/mol"`
Discussion
515.

For a fixed amouunt of an ideal gas`(gamma=(11)/(9))`, the change in internal energy of the gas when pressure changes from 10 bar to 20 bar in rigid vessel of volume 5 L is given by :A. 225 JB. 22.5 kJC. 15 kJD. 36 kJ

Answer» Correct Answer - B
Discussion
516.

Determine enthalpy of formation for `H_(2)O_(2)(l)`, using the listed enthalpies of reaction : `N_(2)H_(4)(l)+2H_(2)O_(2)(l)toN_(2)(g)+4H_(2)O(l)`, `" "Delta_(r)H_(1)^(@)=-818kJ//mol` `N_(2)H_(4)(l)+O_(2)(g)toN_(2)(g)+2H_(2)O(l)` `" "Delta_(r)H_(2)^(@)=-622kJ//mol` `H_(2)(g)+(1)/(2)O_(2)(g)toH_(2)O(l)" "Delta_(r)H_(3)^(@)=-285kJ//mol`A. `-383` kJ/molB. `-187` kJ/molC. `-498` kJ/molD. None of these

Answer» Correct Answer - B
For `H_(2)(g)+O_(2)(g)rarrH_(2)O_(2)(l)`
`Delta_(f)H^(@)(H_(2)O_(2),l)=Delta_(r )H_(3)^(@)+(Delta_(r )H_(2)^(@))/(2)-(Delta_(r )H_(1)^(@))/(2)`
Discussion
517.

Determine `Delta U^(@) ` at 300K for the following reaction using the listed enthalpies of reaction : `4CO(g)+8H_(2)(g)to3CH_(4)(g)+CO_(2)(g)+2H_(2)O(l)` `C("graphite")+(1)/(2)O_(2)(g)to CO(g), DeltaH_(1)^(@)=-110.5KJ`` CO(g)(1)/(2)O_(2)(g)toCO_(2)(g), DeltaH_(2)^(@)=-282.9KJ` `H_(2)(g)+(1)/(2)O_(2)(g)to H_(2)O(l), DeltaH_(3)^(@)=-285.8KJ` `C("graphite")+2H_(2)(g)to CH_(4)(g), DeltaH_(4)^(@)=-74.8KJ`A. `-653.5 KJ`B. `-686.2 KJ`C. `-747.4 KJ`D. None of these

Answer» Correct Answer - D
`DeltaH^(@) =- 3DeltaH_(1)^(@)DeltaH_(2)^(@) + 2DeltaH_(3)^(@) + 3DeltaH_(4)^(@)`
`=-747.4` KJ
`DeltaH^(@) =DeltaU^(@) + Deltan_(g) RT , "where" Deltan_(g) =- 8`
`747.4 = DeltaU^(@) - (8xx8.314 xx300)/(1000)`
`DeltaU^(@)=-747.44` KJ.
Discussion
518.

Which of the followig substances willl have non-zero standard enthalpy of formation ? `DeltaH_(f)^(@)ne0`A. `H^(+)(aq)`B. `C_((graphite))`C. `Rn_((gas))`D. `Sn_((grey))`

Answer» Correct Answer - D
Discussion
519.

Calculate `Delta` E when one mole of liuid is vaporized at its boiling point (`80^(@)C`) and 1atm pressure . `[DeltaH_(vap)=30.7KJ//mol]`A. 33.6KJB. 31.4KjC. 30.0KJD. 27.8KJ

Answer» Correct Answer - d
Discussion
520.

Which of the following reactions is asssociated with the most negative change in entropy?A. `2SO_(2)(g)+O_(2)(g) to2SO_(3)(g)`B. `C_(2)H_(2)(g)+H_(2)(g) to C_(2)H_(4)(g)`C. `C(s, "graphite") +O_(2)(g)toCO_(2)(g) `D. `3C_(2)H_(2)(g)to C_(6)H_(6)(l)`

Answer» Correct Answer - D
Discussion
521.

Determine enthalpy of formation for `H_(2)O_(2)(l)`, using the listed enthalpies of reaction : `N_(2)H_(4)(l)+2H_(2)O_(2)(l)toN_(2)(g)+4H_(2)O(l)`, `" "Delta_(r)H_(1)^(@)=-818kJ//mol` `N_(2)H_(4)(l)+O_(2)(g)toN_(2)(g)+2H_(2)O(l)` `" "Delta_(r)H_(2)^(@)=-622kJ//mol` `H_(2)(g)+(1)/(2)O_(2)(g)toH_(2)O(l)" "Delta_(r)H_(3)^(@)=-285kJ//mol`A. `-383" kJ"//mol`B. `-187" kJ"//mol`C. `-498" kJ"//mol`D. None of these

Answer» Correct Answer - B
Discussion
522.

Calculate change in enthalpy when 2 moles of liquid water at 1 bar and `100^(@)` C is coverted into steam at 2 bar and `300^(@)`. Assume `H_(2)O` vapoures to behave ideally. [Latent heat of vaporisation of `H_(2)O(l)` at 1 bar and `100^(@)` C id=s 10.8 kcal per mole] [R=`2cal//"mol" K`]A. 21.6 kcalB. 11.8 kcalC. 24.8 kcalD. 23.6 kcal

Answer» Correct Answer - C
Discussion
523.

Read following statement(s) carefully and select the right option : (I) The enthalpy of solution of `CaCl_(2). 6H_(2)O` in a large volume of water is endothermic to the extent of 3.5 kcal/mol. If `DeltaH=-23.2 " kcal"` for the reaction, `CaCl_(2)(s)+6H_(2)O(l)rarrCaCl_(2).6H_(2)O(s)` then heat of solution of `CaCl_(2)` (anhydrous) in a large volume of water is - 19.7 kcal/mol (II) For the reaction `2Cl(g)rarrCl_(2)(g)`, the sign of `DeltaH` and `DeltaS` are negative.A. Statement I and II both are wrongB. both are correctC. only I is correctD. only II is correct

Answer» Correct Answer - B
`CaCl_(2)(s)+aqrarrCaCl_(2)(aq)+q`
`(CaCl_(2)(aq)+6H_(2)O(l)rarrCaCl_(2).6H_(2)O(s)+23.2)/(CaCl_(2)(s)+6H_(2)OrarrCaCl_(2).6H_(2)O(s)+q+23.2)`
`3.5 = q + 23.2`
`q = - 19.7`
(II) 2 Cl (g) `rarrCl_(2)(g)`
`DeltaH=-ve, DeltaS=-ve`.
Discussion
524.

Which of the following graphs given below show (s) adiabatic process? A. II, IIIB. I, IIIC. II, IVD. I, IV

Answer» Correct Answer - A
Adiabatic slope are more steeper than isothermal. Slope of adiabatic process `= gamma xx` slope of isothermal process
Discussion
525.

For the transformation, `H_(2)O(l,1 atm) "to H_(2)O ` `(g,1atm),` `DeltaH_(vap)=40.668kJmol^(-)` The change in entropy `(JK^(-)mol^(-)) is: `A. `19.14`B. `89.89`C. `109.03`D. `128.17`

Answer» Correct Answer - D
Discussion
526.

A 9.40 g sample of KBr is dissolved in 105 g of `H_(2)O` at `23.6^(@)` C in a coffee cup. Find the final temperature of this system. Assume that no heat is transferred to the cup or the surroundings. A. `20.0^(@)` CB. `20.3^(@)` CC. `26.9^(@)` CD. `27.2^(@)` C

Answer» Correct Answer - B
Discussion
527.

a Coffee cup calorimeter initially contains 125 g of water , at a temperature of `24.2^(@)`C ,8 of ammonium nitrate `(NH_(4)NO_(3))` also at `24.2^(@)C`is added to the Water and the final temperature is `18.2^(@)c` What is the heat of solution of ammonium nitrate in KJ /mol? (The specific heat capacity of the solution is `4.2J//^(@)c`.)A. 33.51 kJ/molB. 39.5 kJ/molC. 32.2 kJ/molD. 37.3 kJ/mol

Answer» Correct Answer - A
`DeltaH_("solution")=((125+8)xx4.2xx6)/(8)xx80=33516" J"//"mol or 33.51 kJ"//"mol"`
Discussion
528.

Which of the following options will be correct for the stage of half competiton of the reaction `A to B?`A. `DeltaG^(@)=0`B. `DeltaG^(@)gt0`C. `DeltaG^(@)lt0`D. `DeltaG^(@)=-RT In2 `

Answer» Correct Answer - A
Discussion
529.

A coffee cup calorimeter initially contains 125 g of water at a temperature of `24.2^(@)C`. After adding 10.5 gm `KBr` temperature becomes `21.1^(@)C`. The heat of solution isA. 85 J/gB. 110 J/gC. 270 J/gD. 167 J/g

Answer» Correct Answer - D
`DeltaH=ms DeltaT`
Discussion
530.

Heat of combustion of ethanol at constant pressure and at temperature TK is found to be `-q J" mol"^(-1)`. Hence, heat of combustion (in J `mol^(-1)`) of ethanol at the same temperature and at constant volume will be :A. `RT-q`B. `-(q+RT)`C. `q-RT`D. `q+RT`

Answer» Correct Answer - A
Discussion
531.

a Coffee cup calorimeter initially contains 125 g of water , at a temperature of `24.2^(@)`C ,8 of ammonium nitrate `(NH_(4)NO_(3))` also at `24.2^(@)C`is added to the Water and the final temperature is `18.2^(@)c` What is the heat of solution of ammonium nitrate in KJ /mol? (The specific heat capacity of the solution is `4.2J//^(@)c`.)A. 33.51kJ /molB. 39.5kJ/molC. 32.2kJ/molD. 37.3kJ/mol

Answer» Correct Answer - a
Discussion
532.

For which of the following process would `DeltaS ` be expected to be most positive?A. `C_(6)H_(12)O_(6)(g) to 6CO_(2)(g)+6H_(2)O(g)`B. `CO_(2)(g) toCO_(2)(s)`C. `Na^(+)(aq)+ Cl^(-)(aq) toNaCl(s)`D. `Cl_(2)(g)+H_(2)(g) to2HCl(g) `

Answer» Correct Answer - A
Discussion
533.

The normal boiling point of a liquid A is 300K. Which of the following statement is false about the process: `A(l) toA(g)? `A. at 300K and 1 atm pressure `DeltaG=0`B. at 300K and 2atm pressure `DeltaG=+ve`C. at 300K and 0.1 atm pressure `DeltaG=-ve`D. at 310K and 1 atm pressure `DeltaG=+ve`

Answer» Correct Answer - D
Discussion
534.

One gram mole of an ideal gas at `N.T.P` is first expanded isothermally to twice the origional volume. It is then compressed at constant volume, till its pressure is raised to the original value. Calculate the total amount of work done. Given `R= 8.3 mol e^(_1)K^(-1)`.

Answer» Correct Answer - `1.57xx10^(3)J`
Discussion
535.

One mole of argon is expanded according to process equation `PV^(1.5)=`constant and its temperature falls by 26 K, thenA. Heat exchanged is 108 JB. Heat exchanged is zeroC. Work done by gas is 432 JD. Work done by gas is 39 J

Answer» Correct Answer - A::C
Discussion
536.

An ideal monoatomic gas is taken around the cycle ABCDA, wher co-ordinates of A, B, C and D on and D on `P-V` diagram are A`(p,V), B(2p,V), C(2p, 2V) and D(p, 2V)`. Calculate work done during the cycle.

Answer» Correct Answer - `pV`
Discussion
537.

Stearic acid `[CH_(3)(CH_(2))_(16)CO_(2)H]` is a fatty acid the part of fat that stores most of the energy .1.0 g of Stearic acid was burnt in a bomb calorimeter . The bomb had capacity of 652 `J//^(@)C`. If the temperature of 500 g water rose from 25.0 to `39.3^(@)C` how much heat is released when the stearic acid was burned? `["Given "C_(p)(H_(2)O)=4.18J//g^(@)c]`A. 39.21kjB. 29.91KjC. 108KjD. 9.32Kj

Answer» Correct Answer - a
Discussion
538.

Stearic acid `[CH_(3)(CH_(2))_(16)CO_(2)H]` is a fatty acid the part of fat that stores most of the energy .1.0 g of Stearic acid was burnt in a bomb calorimeter . The bomb had capacity of 652 `J//^(@)C`. If the temperature of 500 g water rose from 25.0 to `39.3^(@)C` how much heat is released when the stearic acid was burned? `["Given "C_(p)(H_(2)O)=4.18J//g^(@)c]`A. 39.21 kJB. 29.91 kJC. 108 kJD. 9.32 kJ

Answer» Correct Answer - A
`-q_("reaction")=q_("bomb")+q_("water")`
`q_("reaction")=(C("bomb")+(m_("water")xxc))DeltaT`
`=(652 + 500 xx 4.18 )xx14.3`
`=39210 " J or "39.21" kJ"`
Discussion
539.

A 0.05 L sample of 0.2 M aqueous hydrochloric acid is added to 0.05 L of 0.2 M aqueous ammonia in a calorimeter. Heat capacity of entire calorimeter system is 480 J/K. The temperature increase is 1.09 K. Calculate `Delta_(r )H^(@)` in kJ/mol for the following reaction : `HCl(aq.)+NH_(3)(aq.)rarrNH_(4)Cl(aq.)`A. `-52.3`B. `-61.1`C. `-55.8`D. `-58.2`

Answer» Correct Answer - A
m mole of acid `= 0.05 xx 0.2 = 0.01`
`Delta_(r)H^(@) = (480 xx 1.09)/(0.01 xx 1000) = -52.32 kJ//mol`
Discussion
540.

One mole of a monoatomic ideal gas is taken through the cycle ABCDA as shown in the figure. `T_A=1000K` and `2p_A=3p_B=6p_C` `[Ass um e(2/3)^0.4=0.85` and `R=(25)/(3)JK^-1mol^-1]` The temperature at B isA. 350 KB. 1175 KC. 850 KD. 577 K

Answer» Correct Answer - C
Discussion
541.

Stearic acid `[CH_(3)(CH_(2))_(16)CO_(2)H]` is a fatty acid the part of fat that stores most of the energy .1.0 g of Stearic acid was burnt in a bomb calorimeter . The bomb had capacity of 652 `J//^(@)C`. If the temperature of 500 g water rose from 25.0 to `39.3^(@)C` how much heat is released when the stearic acid was burned? `["Given "C_(p)(H_(2)O)=4.18J//g^(@)c]`A. `39.21 kJ`B. `29.91 kJ`C. `108 kJ`D. `9.32 kJ`

Answer» Correct Answer - A
`-q_("reaction") = q_("bomb")+q_("water")`
`-q_("reaction") = [C(bomb)+(m_("water") xx c)] delta T`
`= (652 + 500 xx 4.18) xx 14.3 = 39210 J` or `39.21 kJ`
Discussion
542.

One mole of a monoatomic ideal gas is taken through a cycle ABCDA as shown in the PV diagram. Column -II gives the characterstics involved in the cycle. Match them with each of the processes given in column -I

Answer» Correct Answer - A::B::C::D
`A rarr B`: work is done on gas heat is lost
Internal energy decrease.
`B rarr C`: Internal energy decreases, Heat is lost
`C rarr D` : Internal energy increase Heat is gained
`D rarr A`: Heat is lost work is done on gas
Discussion
543.

If R = universal gas constant, the amount of heat needed to raise the temperature of 2 mole of an ideal monoatomic gas from 273 K to 373 K when no work is doneA. 100 RB. 150 RC. 300 RD. 500R

Answer» Correct Answer - C
Discussion
544.

The correct relationship between free energy change in a reaction and the corresponding equilibrium constant K isA. `-DeltaG^(@)= RT ln K`B. `DeltaG= RT ln K`C. `-DeltaG= RT ln K`D. `DeltaG^(@)= RT ln K`

Answer» Correct Answer - A
`DeltaG^(@) = - RT In K `
Discussion
545.

What is `Delta_(r)G`(KJ/mol) for sysnthesis of ammonia at 298K at following sets of partial pressure: `N_(2)(g) + 3H_(2)(g) hArr 2NH_(3) , Delta_(r) G^(@) = - 33 KJ//mol`.`[Take R= 8.3J//K "mole", log2 = 0.3, log3= 0.48]` `underset("Pressure(atm)")(Gas)" "underset(1)(N_(2))" "underset(3)(H_(2))" "underset(0.02)(NH_(3))`A. ` +6.5`B. `-6.5`C. `+60.5`D. `-60.5`

Answer» Correct Answer - D
`DeltaG= DeltaG^(@) +2.303 RT log Q`
`Q=(0.02)^(2)/(1 xx 3^(3))`
` = - 60.5 kJ//Mol`
Discussion
546.

Which of the following substances will have positive value of `DeltaH_("formation")`?A. `Br_(2)(l)`B. `O_(3)(g)`C. ZnO(s)D. `H^(+)(aq)`

Answer» Correct Answer - B
Discussion
547.

The value of `DeltaG_(f)^(@)` of gaseous mercury is `31 K J //"mole"`. At what total external pressure mercury start boiling at `25^(@)C`. `[R=8.3 J// "K mole"]`A. `10^(-5.44)`B. `10^(-12.5)`C. `10^(-6.52)`D. `10^(-3.12)`

Answer» Correct Answer - A
`DeltaG^(@) =- 2.303 RT log kp`
`K_(P) = P = 10^(-5.44)`
Discussion
548.

For a reaction `A(s)to B(s), DeltaG_(300)^(@)=-2kJ//"mole" ` Where A and B ar allotropic forms. At what external pressure will the reaction attain equillbrium at 300K, if specific volume of A and B are 10mL//g and 15mL//g respectively and molar mass of A is 40g:A. `100Pa`B. `100"bar"`C. `101Pa`D. `101"bar"`

Answer» Correct Answer - D
Discussion
549.

For a reaction : `2A (s) + B(g)rarr3C(l)` standard entropy change of reaction is `2kJ//mol-K` and standard enthalpy of combustion of A,B and C are `-100,-60,285` kJ/mol respectively, them find the maximum useful work that can be obtained at `27^(@)C` and 1 bar pressure for reaction `("in kJ/mol")`.

Answer» Correct Answer - 5
Discussion
550.

When the common salt dissolves in water, the entropy of the system increases. This means that the sign of `Delta`S is ______ and randomness of the system _______A. Undetermined, increasesB. Positive, decreasesC. Positive, increasesD. Negative, decreases

Answer» Correct Answer - C
Discussion