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This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
For the reaction, `A+2B to 5C+3D` the rate of formation of C is 0.06 mole/L/sec and final concentration of B is 0.04 mole`//L^(-1)` at 2 sec. Find out the initial concentration of B and also the change in concentration of B. |
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Answer» Rate of disappearance of `B=(-1)/(2)([B])/(Delta t)` Rate of formation of `C=(1)/(5)([C])/(Delta t)` Rate disappearance of `B=(2)/(5)` rate of formation of C `=(2)/(5)xx0.06=0.024 " moles L"^(-1) s^(-1)` We know `r_(B)=(-Delta[B])/(Delta t)` Rate of disappearance of `B=("initial concentration - final concentration ")/(" change in time ")` `0.024=(x-0.04)/(2)` `0.024xx2=x-0.04` `0.048+0.04=x=0.088 " mole" //L` `therefore` Initial concentration of B is 0.088 mole/L `therefore` Change in concentration of B=0.088-0.04=0.048 mole/L |
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| 2. |
Which of the following statements regarding a catalyst is false ?A. It may increase or decrease rate of a reaction.B. It is highly specific in its action.C. It remains unchanged at the end of a chemical reaction.D. A catalyst changes that state of equilibrium in a chemical reaction. |
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Answer» Correct Answer - A A catalyst does not change the state of equilibrium in a chemical reaction. |
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| 3. |
Assertion (A) : In the preparation of oxygen from `KClO_(3),MnO_(2)` acts as a positive catalyst. Reasson (R ) : `MnO_(2)` decreases the activation energy of the reactionA. Both A and R are correct is the correct explanation of A.B. Both A and R are correct and R is not the correct explanation of A.C. A is correct and R is wrongD. A is wrong and R is correct. |
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Answer» Correct Answer - A Positive catalyst decreases the activation energy of the reaction. Hence, the rate of reaction increases. |
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| 4. |
If the activation energy of forward reaction is four times the amount of energy released `(DeltaH= -10` kcal), what could be the activation energy of the backward reaction ?A. 50 kcalB. 60 kcalC. 40 kcalD. 30 kcal |
| Answer» Correct Answer - A | |
| 5. |
`(a) 2A_((g)) hArr 2B_((g))+C(g)` `(b) X_((g)) hArr Y_((g)) + Z_((g))` `(c ) 2P_((g)) hArr Q_((g))+R_((g))` `(d) 2R_((g)) hArr 3S_((g))+2T_((g))` The above reactions are carried out in four separate closed vessels of same volume and same temperature is maintained throughout. If all the reactions are inititained throughout. If all the reactions are initiated with with equal number of moles of the reactants and their degrees of dissociation are same, arrange them in the increasing order of pressure after the reactions attain equilibrium.A. c a d bB. a c b dC. c a b dD. b a c d |
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Answer» Correct Answer - A `(i) 2P(g) hArr Q(g)+R(g)` `(ii) 2A(g) hArr 2B(g)+C(g)` `(iii) X(g) hArr Y(g)+Z(g)` (iv)` 2R(g) hArr 3S(g)+2T(g)` |
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| 6. |
For the reaction involving the formation of 1 mole fo water molecule from hydrogen and oxygen, the rate of rection with respect to reactants is given asA. `r=(1)/(2)(Delta [H_(2)])/(Delta t)`B. `r=-(1)/(2)(Delta [H_(2)])/(Delta t)`C. `r=-(1)/(2)(Delta[O_(2)])/(Delta t)`D. `r=-(Delta[H_(2)])/(Delta t)` |
| Answer» Correct Answer - D | |
| 7. |
In the formation of `NH_(3)` from nitrogen and hydrogen, rate with respect to `H_(2) " is" (2)/(3)` the rate of `NH_(3)`. |
| Answer» Correct Answer - False | |
| 8. |
The activation energy for the forward reaction of `A+B hArr C+D` is 50 kJ/mole. If the energy of the products is 10 kJ mole more than that of reactants, the activation energy for the formation of reactants from the products isA. 60 kJ/moleB. 30 kJ/moleC. 40 kJ/moleD. 50 kJ/mole |
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Answer» Correct Answer - A Activation energy for forward reaction is 50 kJ/mole. If the energy of the products is 10 kJ/mole is more than that of reactants, the activation energy for the formation of reactants from the products is 40 kJ/mole. |
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| 9. |
Write the equilibrium expressions `(K_(C ))` for the decomposition of 2 moles of sulphur trioxide and relate it to `K_(C )` of the reaction carried out with 1 mole and 4 moles of `SO_(3)`, respectively. |
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Answer» `K_(c )` value for the equilibrium reaction `2SO_(3) implies 2SO_(2)+O_(2)` is `K_(c_(1))`=([SO_(2)]^(2)[O_(2)])/(SO_(3)]^(2))` `K_(c )` value for the equilibrium reaction `SO_(3) implies SO_(2)+(1)/(2)O_(2)` is `K_(c_(2))=([SO_(2)][O_(2)]^(1/2))/([SO_(3)])` `therefore_(c_(2))=K_(c_(1))^(2)` `K_(c )` value for the equilibrium reaction `4SO_(3) implies 4SO_(2)+2O_(2)` is `K_(c_(3))=([SO_(2)]^(4)[O_(2)]^(2))/([SO_(3)]^(4)` `therefore K_(c_(3))=sqrt(K_(c_(1)))` |
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| 10. |
`2A + 4B to 3C + 5D` In the given reaction, the rates of reaction with respect to A, B, C and D are `(a) r_(A) " " (b) r_(B)` `(c ) r_(C ) " " (d) r_(D)` Arrange them in the ascending order of their magnitude.A. a c b dB. a d b cC. a b c dD. d b c a |
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Answer» Correct Answer - A `r=(-1)/(2)(Delta [A])/(Delta t)=(-1 Delta[C])/(4 Delta t)=(1)/(3)(Delta[C])/(Delta t)=(1)/(5)(Delta [D])/(Delta t)` `(i) r_(A) " " (ii) r_(C )` (iii) ` r_(B) " " (iv) r_(D)` |
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| 11. |
For the equilibrium, `N_(2)+3H_(2) hArr 2NH_(3)`, if deuterium is introduced into the reaction mixture after equilibrium, the final composition of equilibrium mixture isA. `NH_(3), ND_(3)`B. `NH_(3), ND_(3),H_(2),D_(2),N_(2)`C. `NH_(3),D_(2),N_(2)`D. `ND_(3),H_(2),N_(2)` |
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Answer» Correct Answer - A `2N_(2)+3H_(2)+3D_(2)2NH_(3)+2ND_(3)` |
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| 12. |
For the equilibrium reaction, dissociation of calcium carbonate `K_(c )` is equal to _____. |
| Answer» Correct Answer - concentration of carbon dioxide | |
| 13. |
For the reaction `PCl_(5) hArr PCl_(5)+Cl_(2)`, there is no effect of pressure. |
| Answer» Correct Answer - False | |
| 14. |
Consider the reaction `NO+(1)/(2)O_(2) hArr NO_(2)`. Which of the following gives the value of `K_(c )` for this equilibrium ?A. `K_(c )=([NO][O_(2)]^(1//2))/([NO][O_(2)])`B. `K_(c )=([NO_(2)])/([NO][O_(2)])`C. `K_(c )=([NO_(2)])/([NO][O_(2)]^(1//2))`D. `K_(c )=([NO_(2)])/([NO]^(2)[O_(2)])` |
| Answer» Correct Answer - C | |
| 15. |
`CaCO_(3(g)) hArr CaO_((s))+CO_(2(g))`. This reaction becomes irreversible because ____. |
| Answer» Correct Answer - `CO_(2)` gaseous product | |
| 16. |
Which of the following equilibrium shifts in the backward direction by applying high pressure ?A. `N_(2)O_(4)(g)_(to)^(larr)2NO_(2)(g)`B. `H_(2(g))+Cl_(2(g)_(to)^(larr))2HCl(g)`C. `N_(2(g))+3H_(2(g)_(to)^(larr))2NH_(3(g))`D. `PCl_(2(g))+Cl_(2(g)_(to)^(larr))PCl_(5(g))` |
| Answer» Correct Answer - A | |