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InterviewSolution
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.
| 1301. |
The rate equation for the decomposition of `N_(2)O_(5)` in `C Cl_(4)` is rate `=K[N_(2)O_(5)]`, where `K=6.3xx10^(-4) s^(-1)` at `320K`. What would be the initial rate of decomposition of `N_(2)O_(5)` in a `0.10 M` solution of `N_(2)O_(5)` ?A. (a) `6.3xx10^(-6) mol litre^(-1) s^(-1)`B. (b) `0.63xx10^(-6) mol litre^(-1) s^(-1)`C. (c ) `6.3xx10^(-5) mol litre^(-1) s^(-1)`D. (d) `0.63xx10^(-4) mol litre^(-1) s^(-1)` |
| Answer» Correct Answer - c, d | |
| 1302. |
`ArarrB, DeltaH= -10 KJ mol^(-1), E_(a(f))=50 KJ mol^(-1)`, then `E_(a)` of `BrarrA` will beA. `40 kJ "mol"^(-1)`B. `50 kJ "mol"^(-1)`C. `-50 kJ "mol"^(-1)`D. `60 kJ "mol"^(-1)` |
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Answer» Correct Answer - D `A rarr B, Delta H_(f) = -10kJ mol^(-1)` (Exothermic) `:. B rarr A, Delta H_(b) + 10 kJ mol^(-1)` (endthermic) `:. (E_(a))_(b) = Delta H_(b) + (E_(a))_(f)` `= 10 + 50` `= 60 kJ mol^(-1)` |
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| 1303. |
In the reaction, `3BrO^(-)rarrBrO_(3)^(-)+2Br^(-)` (aqueous alkaline medium at `80^(@)C`) the vlaue of the rate constant in the rate law in terms of `--(d)/(dt)[BrO^(-)]` is `0.056 L "mol"^(-1)s^(-1)`. What will be the rate constant when the law is stated in terms of `(d)/(dt)[BrO^(-)]`?A. (a) `18.7xx10^(-3) litre mol^(-1) s^(-1)`B. (b) `3.74xx10^(-3) litre mol^(-1) s^(-1)`C. (c ) `0.0187 litre mol^(-1) s^(-1)`D. (d) `18.7xx10^(-2) litre mol^(-1) s^(-1)` |
| Answer» Correct Answer - a, c | |
| 1304. |
Which of the following statements is (are) true?A. (a) Law of mass action and rate law expressions are same for single step reactionsB. (b) Order for the slowest elementry reaction of a multi-step reaction gives the oder of the multi-step reactionC. (c ) Both order and molecularity have normally a maximum value of `3`D. (d) Molecularity of a complex reaction, `A+2Brarr C` is `3` |
| Answer» Correct Answer - a, b, c | |
| 1305. |
Arrhenius equation may be written as:A. (a) `(d//dt)log K=-(DeltaU//RT^(2))`B. (b) `(d//dt)log K=+(DeltaU//RT^(2))`C. (c ) `(d//dt)log K=-(DeltaU//RT)`D. (d) `K=Ae^(-DeltaU//RT)` |
| Answer» Correct Answer - a, b | |
| 1306. |
`{:(I.,E_(a)=15m "kJ mol"^(-1),,DeltaH=-70 "kJ mol"^(-1)),(II.,E_(a)=30"kJ mol"^(-1),,DeltaH=-15 "kJ mol"^(-1)),(II.,E_(a)=60 "kJ mol"^(-1),,DeltaH=+250"kJ mol"^(-1)):}` If above reactions are at same frequency factor then fastest and slowest reaction are:A. III is fastest, II is slowestB. I is fastest, III is slowestC. II is fastest, III is slowestD. III is fastest, I is slowest |
| Answer» Correct Answer - B | |
| 1307. |
Arrhenius equation may be given as :A. `ln.(A)/(k)=(E_(0))/(RT)`B. `logA=logk+(E_(a))/(0.303RT)`C. `log[(-overset(.)E_(a))/(RT)]=(k)`D. `(dlnk)/(dt)=(E_(a))/(RT)` |
| Answer» Correct Answer - A::B | |
| 1308. |
The rate of reaction between `A` and `B` increases by a factor of `100`, when the concentration with respect to `A` is increased `10` folds, the order of reaction w.r.t. `A` isA. `10`B. `1`C. `4`D. `2` |
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Answer» Correct Answer - D `r = K[A]^(n), 100r = K[10 A]^(n)` Thus `(1)/(100) = ((1)/(10))^(n)` or `n = 2` |
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| 1309. |
The rate of reaction between `A` and `B` increases by a factor of `100`, when the concentration with respect to `A` is increased `10` folds, the order of reaction w.r.t. `A` is |
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Answer» Correct Answer - B Rate `=[A]^(n) therefore 100=(10)^(2) therefore n=2` |
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| 1310. |
The rate of reaction between A and B increases by a factor of 100 , when the concentration of A is increased 10 folds . The order of reaction with respect to A isA. 10B. 1C. 4D. 2 |
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Answer» Correct Answer - d `r = k[A]^(n) , 100 r = k [10A]^(n)` Thus `(1)/(100) = ((1)/(10))^(n) ` or n = 2. |
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| 1311. |
The rate of reaction between `A` and `B` increases by a factor of `100`, when the concentration with respect to `A` is increased `10` folds, the order of reaction w.r.t. `A` isA. 10B. 2C. 1D. 30 |
| Answer» Correct Answer - B | |
| 1312. |
A reaction having rqual energies of activation for toward and reverse reaction hasA. `Delta G = 0`B. `Delta H = 0`C. `Delta H = Delta G = Delta S = 0`D. `Delta S = 0` |
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Answer» Correct Answer - B `Delta H = E_(a_(f)) - E_(a_(b)) = 0` |
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| 1313. |
Which of the following statement is not correct about order of a reaction ?A. The order of a reaction can be a fractional number.B. Order of a reaction is experimaentally determined quantityC. The order or a reaction is always equal to the sum of the stoichiometic coefficients of reactants in the balanced chemical equaiton for a reaction.D. The order of a reaction is the sum of the powers of molar concentration of the reactants in the rate law expression. |
| Answer» Correct Answer - C | |
| 1314. |
Assertion : Precipitation of silver chloride occurs instantaneously by mixing of aqueous solutions of silver nitrate and sodium chloride. Reason : Ionic reactions occur very fast.A. If both assertion and reason are true and reason is the correct explanation of assertion.B. If both assertion and reason are true but reason is not the correct explanation of assertion.C. If assertion is true but reason is false.D. If both assertion and reason are false. |
| Answer» Correct Answer - A | |
| 1315. |
According to…………..theory of catalyiss, there are some……….centres with……….valencies. |
| Answer» Correct Answer - adsorption, active, free | |
| 1316. |
Rate of reaction is given by the eqution : Rate = `k[A]^(2)[B]`. What are the units for the rate and rate constant for the reaction? |
| Answer» Units of rate = Mol `L^(-1)s^(-1)`. Units of rate constant(k) = `L^(2)mol^(-2)s^(-1)` | |
| 1317. |
Assertion: The reaction `2NO+O_(2) to 2NO_(2)` and `2CO + O_(2) to CO_(2)` proceed at the same rate because these are similar. Reason: Both reactions have same activation energy.A. If both assertion and reason are correct explanation for assertion.B. If both assertion and reason are correct but reason is not correct explanation for assertion.C. If assertion is correct but reason is incorrect.D. If both assertion and reason are incorrect. |
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Answer» Correct Answer - D d) Correct assertion: The listed reactions donot proceed with the same rate. Correct reason: The listed reactions donot have same activation energy. |
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| 1318. |
How can you determine the rate law of the following reactions? `2NO(g) + O_(2)(g) to 2NO_(2)(g)` |
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Answer» The rate law for the reaction can be determined experimentally. Firstly, the concentration of one of the reactants (e.g. `O_(2)`) is taken in large excess and the reaction rate is determined with respect to NO(g). Then the other reactant i.e. NO is taken in large excess and the reaction rate is determined with respect to `O_(2)` (g). The rate law expression for the reaction may be expressed as Rate = `k[NO]^(x)[O_(2)]^(y)` Where x and y are the equal coefficients of the reacting taking part in the reaction. |
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| 1319. |
The rate law of a chemical reaction given below: `2NO+O_(2)rarr 2NO_(2)` is given as rate `=K[NO]^(2)[O_(2)]`. How will the rate of reaction change if the volume of reaction vessel is reduced to `1//4th` of its original valur? |
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Answer» When volume is reduced to 1/3rd , then concentration will increase three times. `r_(1)=k[A][B]^(2)" ".....(i)` `r_(2)=k[3A][3B]^(2)" ".....(ii)` From eqs. (i) and (ii), `r_(1)/(r_(2))=(1)/(27)` `r_(2)=27r_(1)` `:.` Rate will increases 27 times. |
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| 1320. |
A,B,C and D elements form compounds AC, `A_(2)D` and BD. If AC and `A_(2)D` are radioactive and BD is not radioactive compound, then which among the following pair of compounds may not be radioactive:A. `A_(2) and BD`B. `BD and B_(2)C`C. `AD and C_(2)D`D. `B_(@)C and AD` |
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Answer» Correct Answer - B |
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| 1321. |
For the given reaction, `A+B rarr` Products following data were obtained (i) Write the rate law expression. (ii) Find the rate constant. |
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Answer» Let order respect to A and B are `alpha and beta` respectively. Rate law expression may be given as. `"Rate "=k[A]^(alpha)[B]^(beta)` `0.05=k[0.1]^(alpha)[0.2]^(beta)" " ....(i)` `0.10=k[0.2]^(alpha)[0.2]^(beta)" " ....(ii)` `0.05=k[0.1]^(alpha)[0.1]^(beta)" " ....(iii)` Divding eq. (i) by eq. (ii), we get `(1)/(2)=[(1)/(2)],i.e., alpha=1` Dividing eq. (i), (iii), we get `1=[2]^(beta),i.e.,beta=0` Rate `k=[A]^(1)[B]^(0)` Substituting the value of `alpha and beta` in eq. (i), we get `0.05=k[0.1]^(1)]0.2]^(0)` `k=0.5sec^(-1)` |
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| 1322. |
Arsine decomposes on heating to give As and `H_(2)`. The decomposition studied at constant volume and temperature gives the following data. `{:("T in hr.",0,5.5,6.5,8),("P in atm.",0.9654,1.06,1.076,1.1):}` Calculate velocity constant, assuming first-order reaction. |
| Answer» Correct Answer - `4.01xx10^(-2) hr^(-1);` | |
| 1323. |
During a deacay of 952gm `._(92)U^(238) "to" ._(82)Pb^(206) `, total ``18xx10^(24) alpha-"particle"` are emitted , number of half lives completed in this decay are:A. 5B. 4C. 3D. 6 |
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Answer» Correct Answer - B |
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| 1324. |
Reaction `A` follows first order kinetics and reaction `B` follows second order kinetics. If their half lives are equal, compare their rates (i) at the start of the reaction and (ii) after lapse of one half life. |
| Answer» Correct Answer - (a) `0.693, (b) 1.386;` | |
| 1325. |
An elements A undergoes successive radioactive decay following sequences beta^(-),beta^(-),X,beta^(-),Y ` to form product B.A. If X and Y both are `alpha "particles"`, then A and B are isotopesB. If X and Y are positrons then A and B are isobarsC. If X and Y both are `beta-"particles"` then A and B are isobarsD. If X is `alpha-"particle"` and Y is `beta-"particle"` then A and B are isodiaphers |
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Answer» Correct Answer - D |
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| 1326. |
Rate law expression of a reaction is : Rate = `k[A]^(2//3)[B]` Which of the following are correct about the corresponding reaction ?A. Order of reaction `=(2)/(3)+1=(5)/(3)`B. Unit of rate constant = `L^(2//3) "mol"^(-2//3)"sec"^(-1)`C. Unit of rate constant = `"atm"^(-2//3)"sec"^(-1)`D. Unit of rate constant = mol `L^(-1)"sec"^(-1)` |
| Answer» Correct Answer - A::B::C | |
| 1327. |
Which of the following statement are correct about the reaction in presence of catalyst?A. Catalyst does not alter the heat of reactionB. Catalyst alters the equilibrium constant of the reactionC. Catalyst does not alter the `DeltaG^(@)` of the reactionD. Catalyst change the rate constant of forward and backward reaction to the extent |
| Answer» Correct Answer - A::C::D | |
| 1328. |
In the Arrhenius equation , `k=Ae^(-E_(a)//RT)` the Arrhenius constant A will be equal ot the rate constant when :A. `E_(a)=0`B. `T=oo`C. T=0D. `E_(a)=oo` |
| Answer» Correct Answer - A::B | |
| 1329. |
The half-life of iodine-131 is 8.02 days. How long will it take for 80% of the sample to decay?A. 2.6daysB. 12daysC. 19daysD. 32days |
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Answer» Correct Answer - C |
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| 1330. |
Which of the following arepseudo uimolecular reaction?A. `CH_(3)COOC_(2)H_(5)+HOHoverset(H^(+))rarrCH_(3)COOH+C_(2)H_(5)OH`B. `CH_(3)COOC_(2)H_(5)+HOHoverset(H^(-))rarrCH_(3)COOH+C_(2)H_(5)OH`C. `C_(12)H_(22)O_(11)+HOHoverset(H^(+))rarrC_(6)underset("glucose")(H_(12))O_(6)+C_(6)underset("fructose")(H_(12))O_(6)`D. `SO_(2)Cl_(2)(g)rarrSO_(2)(g)+Cl_(2)(g)` |
| Answer» Correct Answer - A::C | |
| 1331. |
The isotope `.^(14)C` undergoes radioactive decay slowly. Which mode of decay is most likey?A. Alpha emissionB. Beta emissionC. Positron emissionD. Electron capture |
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Answer» Correct Answer - B |
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| 1332. |
The activation energy of a reaction is 9 kcal `"mole "^(-1) ` . The increase in the rate cnstant when its temperature is raised from 295 to 300 approximatelyA. `1.289` timesB. `12.89` timesC. `0.1289` timesD. 0.25 |
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Answer» Correct Answer - A `log ""(K_(2))/(K_(1)) =(E_(a). DT )/(2.303RT_(2)T_(1))` `=(9000xx5)/(2.303xx2xx300xx295)=0.1104` `log ""(k_(2))/(k_(1))=0.1104 therefore (K_(2))/(K_(1))=1.289` ` therefore K_(2)=K_(1)xx1.289` |
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| 1333. |
The rate constant is given by the equation `k = P.Ze^(-E_(a)//RT)`. Which factor should register a decrease for the reaction to proceed more rapidly?A. TB. ZC. AD. Ea |
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Answer» Correct Answer - D Lower is energy of activation , faster will be reaction . |
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| 1334. |
`ArarrB, DeltaH= -10 KJ mol^(-1), E_(a(f))=50 KJ mol^(-1)`, then `E_(a)` of `BrarrA` will beA. `40 KJ mol^(-1)`B. `50 KJ mol^(-1)`C. `-50 KJ mol^(-1)`D. `60 KJ mol^(-1)` |
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Answer» Correct Answer - D `A rarr B, DeltaH = -10 KJ mol^(-1)` It is an exothermic reaction. `E_(a(b))=E_(a(f))-(DeltaH)` `=50 -(-10)` `=60 KJ` |
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| 1335. |
Change in which factors affect both the rate and the rate constant of a first order reaction? (P) Temperature (Q) ConcentrationA. P onlyB. Q onlyC. Both P and QD. Neither P nor Q |
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Answer» Correct Answer - A |
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| 1336. |
Two reaction `A to ` products and `B to ` products have rate constant `k_(a)` and `k_(b)` at temperature T and activation energies `E_(a)` and `E_(b)` respectively. If `k_(a) gt k_(b)` and `E_(a) lt E_(b)` and assuming that a for both the reactions is same then :A. At higher temperature `k_(a)` will be greater than `k_(b)`B. at lower temperature `k_(a)` and `k_(b)` will differe more and `k_(a) gt k_(b)`C. as temperature rises `k_(a)` and `k_(b)` will be close to each other in magnitudeD. all of the above |
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Answer» Correct Answer - C |
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| 1337. |
The gaseous decomposition of ozome `2O_(3)rarr3O_(2)` obeys the rate law `r=-(d[O_(3)])/(dt)=(k[O_(3)]^(2))/([O_(2)])` Show that the following mechanims is consistent with the above rate law : `O_(3)overset(K_(eq))hArrO_(2)+O" " ("fast")` `O+O_(3)overset(k_(1))rarr2O_(2)" " ("slow")` |
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Answer» From the slow rate determining step `=-(d[O_(3)])/(dt)=k_(1)[O][O_(3)]` From the fast reaction., `K_(eq)=([O_(2)][O])/([O_(3)])` or `[O]=(K_(eq)[O_(3)])/([O_(2)])` Substituting the value of [O] in the above expression `r=-(d[O_(3)])/(dt)=(k_(1)K_(eq)[O_(3)]^(2))/([O_(2)])=(k[O_(3)]^(2))/([O_(2)])` |
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| 1338. |
For the formation of phosgene from CO(g) and chlorine. `CO(g)+Cl(g)rarr CoCl_(2)(g)` the exermientally detrmined rate equation is, `(d[COcl_(2)])/(dt)=k[CO][Cl_(2)]^(2//3)` Is the following mechanism consistent with the rate equation `{:((i),Cl_(2)hArr2Cl,("fast")),((ii),Cl+COhArrCOCl,("fast")),((iii),COCl+Cl_(2)hArrCOCl_(2)+Cl,("slow")):}` |
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Answer» Multiplying equation (ii) by and adding (i), we get : ltbr `Cl_(2)2COhArr2COCI `K=([COCI]^(2))/([C_(2)][CO]^(2))` `[COCI=(K)^(1//2)[CI_(2)]^(1//2)[CO]" ".....(i)` Slowest step is rate determine hence, Rate =`k[COCI][CI_(2)]" "....(ii)` From eqs(i). and (ii) we, get Rate `=kK^(1//2)[CI_(2)][CI_(2)]^(1//2)[CI_(2)][CO]` Rate `=k[CI_(2)]^(3//2)[CO]` Thus, rate law is in accordane with the mechanism. |
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| 1339. |
The increase in concentration of the reactants lead changes inA. `Delta H`B. collision frequencyC. activation energyD. equilibrium constant. |
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Answer» Correct Answer - B As the concentration of reactants increases the probability of collisions increases hence collision frequency increases. |
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| 1340. |
Rate of a general reaction A + B `to` products can be expressed as follows on the basis of collision theory. Rate `= Z_(AB) e^(-E_(a)//RT)` Which of the following statements is not correct for the above expression?A. Z is collision frequency andis equal to number of collisions per second per unit volume of the reaction mixtureB. `e^(E_(a)//RT)` is the fraction of molecules with kinetic energy equal to or greater than `E_(a)`C. `E_(a)` is activation energy of the reaction.D. All the molecules which collide with one other are effective collisions. |
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Answer» Correct Answer - D Only those collisions in which molecules collide with sufficient energy, called threshold energy and proper orientation are effective collisions. Rest of the molecules collide and bounce back. |
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| 1341. |
Consider the reaction, `2NO(g) + Cl_(2) rarr 2NOCl.` Which of the following is/are required for a successful reaction between NO and `Cl_(2)` molecules? (P) Proper orientation (Q) `"NO"//Cl_(2)` Ratio of 2 to 1 (R) Sufficient collision energyA. Q onlyB. P and R onlyC. Q and R onlyD. P, Q and R |
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Answer» Correct Answer - B |
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| 1342. |
`2NO(g) +Cl_(2)(g) rarr 2NOCl, DeltaH=-38 KJ` If the activation energy for the forward reaction is 62 KJ , what is the activation energy for the reverse reaction?A. 24 KJB. 38 KJC. 62 KJD. 100 KJ |
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Answer» Correct Answer - D |
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| 1343. |
Which of the following is a first order reaction ?A. `NH_(4) NO_(2) to N_(2) + 2H_(2)O`B. `2HI to H_(2) + I_(2)`C. `2NO_(2) to 2NO + O_(2)`D. `2 NO + O_(2) to 2 NO_(2)` |
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Answer» Correct Answer - a It is a standard example of first order because in that reaction rate of reaction affected by only one concentration term. |
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| 1344. |
Rate of which reactions increases with temperature:A. of any reactionB. of exotherminc reactionC. of endothermic reactionD. none |
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Answer» Correct Answer - a Rate=`K["reactant"]` and `K=Ae^(-E_(a)//RT)`. Thus K always increases with temperature because energy of activation is always +ve. Thus rate always increases K and rate do not depend on heta of reaction, i.e., axotherimic or endothermic. |
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| 1345. |
For a first order reaction `A rarr` Products, the half life is 100 seconds. The rate constant of the reaction isA. `6.9 xx 10^(-2) s^(-1)`B. `6.93 xx 10^(-4) s^(-1)`C. `6.93 xx 10^(-3) s^(-1)`D. `6.93 xx 10^(-1) s^(-1)` |
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Answer» Correct Answer - c `t_(1//2) = (0.693)/(k)` `k = 6.93 xx 10^(-3) s^(-1)`. |
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| 1346. |
The rate of the elementary reaction, `2NO+O_(2)rarr 2NO_(2)`, when the volume of the reaction vessel is doubled:A. Will grow eight times of its initial rateB. Reduce to one-eight of its initial rateC. Will grow four times of its initial rateD. Reduce to one-fourth of its initial rate |
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Answer» Correct Answer - b Rate=`K[NO]^(2)[O_(2)]^(1)`, Concentration of each specise are reduced by `1//2` on increasing volume to two times and thus rate becomes `1//8` times of initial rate. |
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| 1347. |
The rate constant `K_(1)` of a reaction is found to be double that of rate constant `K_(2)` of another reaction. The relationship between corresponding activation energies of the two reaction at same temperature `(E_(1) "and" E_(2))` can be represented as:A. `E_(1) gt E_(2)`B. `E_(1) lt E_(2)`C. `E_(1)=E_(2)`D. None of these |
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Answer» Correct Answer - d `K_(1)=A_(1)e^(-E_(1)//RT)` and `K_(2)=A_(2)e^(-E_(2)//RT)` `K_(1)/K_(2)=A_(1)/A_(2)xxe^((E_(2)-E_(1))RT), A_(1)` and `A_(2)` are not given. |
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| 1348. |
For a reaction `2NO(g)+Cl_(2)(g) hArr 2NOCl(g)`.When concentration of `Cl_(2)` is doubled, the rate of reaction becomes two times of the original. When the concentration of `NO` is doubled the rate becomes four times. What is the order of the reactionA. `1`B. `2`C. `3`D. `4` |
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Answer» Correct Answer - C `2NO(g) + Cl_(2(g)) rarr 2NOCl_((g))` Rate `= K[NO]^(2)[Cl_(2)]^(1), :. O.R. = 2 + 1 = 3` |
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| 1349. |
For a reaction `2NO(g)+Cl_(2)(g) hArr 2NOCl(g)`.When concentration of `Cl_(2)` is doubled, the rate of reaction becomes two times of the original. When the concentration of `NO` is doubled the rate becomes four times. What is the order of the reactionA. 1B. 2C. 3D. 4 |
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Answer» Correct Answer - c `2NO_((g)) + Cl_(2(g)) to 2 NOCl_((g))` Rate = `k[NO]^(2) [Cl_(2)]^(1) , therefore O.R. = 2 + 1 = 3`. |
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| 1350. |
Which of the following is note for zero order reaction ?A. B. C. D. |
| Answer» Correct Answer - C | |