Lacto bacillus has generation time 60 min. at 300 K and 40 min. at 400 K. Determine activation energy in `(kJ)/(mol)` . (`R = 8.3 J K^ (–1) mol^(–1)` ) `[ log_e (2/3) = - 0.4 ]`
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In Arrhenius equation for a certain reaction , the values of A and `E_(a)` (activation energy are `4xx10^(13) "sec"^(-1) and 98.6 kJ "mol"^(-1)` respe
Accroding to Arrhenius equation, `k=Ae^(-E_(a)//RT)` or `"log"_(e)k="log"_(e)A-(E_(a))/(RT)"log"_(e)e` `or 2.303 "log"k=2.303"log"_(10)A-(E_(a))/(RT)` or `2.303"log"(1.1xx10^(-3))=2.303"log"K(4xx10)^(13)-(98xx10^(3))/(8.314xxT)` `T=(98.6xx10^(3))/(8.314xx2.303xx16.56)K=310.96K`
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The energy of activation for a reaction is `100 KJ mol^(-1)`. The peresence of a catalyst lowers the energy of activation by `75%`. What will be the e
The arrhenius equation is , `k=Ae^(-E_(a)//R)` In absence of catalyast, `k_(1)=Ae^(-100//RT)` In presence of catalyst, `k_(2)=Ax^(-25//RT)` So, `(k_(2))/(k_(1))=^(75//RT)or2.303 "log" (k_(2))/(k_(1))=(75)/(RT)` `or 2.303 "log" (k_(2))/(k_(1))=(75)/(8.314xx10^(-3)xx293)` `or "log" (k_(2))/(k_(1))=(75)/(8.314xx10^(-3)xx293xx2.303)` or `(k_(2))/(k_(1))=2.314xx10^(13)` As...
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The activation energy of exothermic reaction `ArarrB` is 80 kJ `"mol"^(-1)` . The heat of reaction is `200 kJ "mol"^(-1)`. The activation energy for t
`DeltaH=E_(f)-E_(b)` `-200=80-E_(b)` `E_(b)=280` kJ/mol
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If the half-lives of the first order reaction at 350 K and 300 K are 2 and 20 seconds respectively, the activation energy of the reaction in kJ `"mol"
`log((k_(2))/(k_(1)))=(E_(a))/(2.303R)[(1)/(T_(1))-(1)/(T_(2))]` `log.((t_(1//2))_(t))/((t_(1//2))_(2))=(E_(a))/(2.303R)[(1)/(T_(1))-(1)/(T_(2))]` `log. ((20)/(20))=(E_(a))/(2.303xx8.314)[(1)/(300)-(1)/(350)]` `E_(a)=(1xx2.303xx8.314xx300xx350)/(50)J "mol"^(-1)` `=40208J "mol"^(-1)` `=40.2kJ"mol"^(-1)`
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`T_(50)` of first order reaction is 10 min. starting with 10 `"mol"^(-1)` rate after 20 min is :
Correct Answer - B Remainin concetration of reactant after 20 min `=(1)/(4)xx102.5"mol"L^(-1)` `"Rate"=kxx["Reactant"]=(0.693)/(t_(1//2))xx["Reactant"]` `=(0.693)/(10xx2.5=0.0693xx2.5 "mol"L^(-1) min^(-1)`
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A reaction takes place in three steps with individual rate constant and activation energy, `{:(,"Rate constant","Activation energy"),("Step 1",k_(1),E
Correct Answer - A `Ae^(-E_(a)//RT)=[(Ae^(-E_(a_(1))//RT)xxAe^(-E_(a_(2))//RT))/(Ae^(-E_(a_(3))//RT))]^(2//3)` `=[Ae^((-E_(a_(1))-E_(a_(2))+E_(a_(3)))//RT)]^(2//3)` `E_(a)=(2)/(3)[E_(a_(1))+E_(a_(2))-E_(a_(3))]` `=(2)/(3)[180+80-50]=140 ` kJ/mol
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The S-S bond energy is if `DeltaH_(f)^(@)(E_(t)-S-E_(t))=-147kJ//mol,DeltaH_(f)^(@)(E_(t)-S-S-E_(t))=-202kJ//mol and DeltaH_(f)^(@)S(g)=+223 kJ//mol:`
Correct Answer - C `C_(2)H_(5)-S-C_(2)H_(5)+S(s)toC_(2)H_(5)-S-S-C_(2)H_(5)` `DeltaH_("reaction")=sumDeltaH_(f("products"))^(@)-sumDeltaH_(f("reactants"))^(@)` `=(-202)-(-147)=-55kJ` `DeltaH_("reaction")=sumDeltaH_(f("reactants"))-sum(BE)_("products")` `-55="heat of sublimation of enthalpy of atomisation of sulphur"-BE(S-S)` ltB rgt `BE(S-S)=223+55=278kJ` (Common bonds of reactants and products are rejected.)
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Two elements A and B are such that Bond energy of A-A,B-B `&` A-B are respectively 81 Kcal/mol, 64 Kcal/mol and 88 Kcal/mol. If electronegativity of B
`sqrt(E_(A-A)xxE_(B-B))=sqrt(81xx64)=72` `Delta=E_(A-B)-sqrt(E_(A-A)xxE_(B-B))=90-72=18` `|X_(A)-X_(B)|=0.208sqrt(A)=0.208sqrt(18)=0.88` `X_(A)-30.88rArrX_(A)=3.88` `3-X_(A)=0.88rArrX_(A)=2.12`
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What is the effect of adding a catalyst on (a) Activation energy (Ea), and (b) Gibbs energy (`DeltaG`) of a reaction?
(i) Activation energy of the reaction decreases on adding catalyst. (ii) Addition of catalyst does not alter the value of gibbs energy `(DeltaG)` of the reaction.
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The pattern of mobility stays same from generation to generation.
The pattern of inequality stays same from generation to generation.
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