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Right answer is (b) CO + H2O → CO2 + H2

Explanation: Gas phase reactions in which the number of moles of the product is equal to the number of moles of REACTANT is a constant volume SYSTEM. In CO + H2O → CO2 + H2, 2 moles of reactants form 2 moles of product.

The correct choice is (a) Rate LAW is preferably written in TERMS of partial PRESSURES

The explanation: In most cases, for gas-solid catalyzed reactions we write the rate law in terms of partial pressures as it makes the analysis simpler. Also, it is PREFERABLE because measuring pressure is EASIER than measuring concentration. Partial pressure and concentration are directly related and the rate law can very easily be represented in either form.

Correct choice is (a) an integer, a fractional

Best explanation: Order is empirical, hence can be a fractional value but MOLECULARITY REFERS to the MECHANISM and is applicable only for ELEMENTARY reactions.

The correct choice is (a) True

Easiest EXPLANATION: k = \(koe^{\frac{-E}{RT}}\)

This is known as ARRHENIUS equation and it GIVES the relation between temperature and rate CONSTANT.

Right choice is (c) k=koT\(e^{-\frac{E}{RT}} \)

Easiest EXPLANATION: According to TRANSITION STATE THEORY the relationship between temperature and rate constant is GIVEN by = koT\(e^{-\frac{E}{RT}}. \)

Right choice is (C) Cis-trans ISOMERIZATION

The explanation: Cis-trans isomerization follows elementary RATE laws. Hydrogen bromide formation reaction as well as the reversible catalytic decomposition of isopropylbenzene are non-elementary in NATURE. Rate of vapor phase decomposition of ethanal is proportional to Cethanal^3/2.

Correct choice is (b) Kinetic THEORY of GASES

Best EXPLANATION: ARRHENIUS equation is based on Kinetic theory of gases.

The CORRECT answer is (a) -2

Best explanation: ∆n = 0.5

pA= pA0 – \(\frac{a}{∆n}\) (P – P0)

(PA = PA0) = \(\frac{-1}{0.5}\)(3-2)

(PA = PA0) = -2.

The correct choice is (C) PA = PA0 – (P – P0)

To elaborate: ∆n = 2-1 =1. pA= pA0 – \(\FRAC{a}{∆n}\) (P – P0), a is the stoichiometry of the REACTANT. HENCE,PA = PA0 – (P – P0).

Correct answer is (d) pR = pR0 + \(\FRAC{r}{∆n}\) (P – P0)

The best explanation: For the reaction, AA + BB → RR + sS, pR = CRRT. CR is the product concentration. CRRT = pR0 + \(\frac{r}{∆n}\) (P – P0).

Correct CHOICE is (d) reaction is elementary and MOLECULARITY is two

The EXPLANATION is: ORDER is EQUAL to molecularity when reaction is elementary.

The correct answer is (B) The bulk DENSITY is a function of the flow rate through the bed

To explain: Fluidized catalytic BEDS are mostly used for multi-phase REACTIONS, for example, CUMENE decomposition. They come under flow reactors. The inclusion of fluidized bed offers more resistance to flow and hence results in a pressure drop.

The CORRECT answer is (a) 4928 J/mol

Easy explanation: T1 = 150K, T2 = 300K and k2 = 10k1

When we have two values of K and T

k1=ko\(\sqrt{T1}E^{-\frac{E}{RT1}}\) andk2=ko\(\sqrt{T2}e^{-\frac{E}{RT2}}\)

Modifying it gives

ln⁡(k1)=ln⁡(ko)+0.5ln⁡(T1) – \((\frac{E}{R})\frac{1}{T1}\) and ln⁡(k2)=ln⁡(ko) – \((\frac{E}{R})\frac{1}{T2} \)

On further simplification we getln⁡⁡\((\frac{k1}{k2}) = 0.5ln⁡(\frac{T1}{T2}) \frac{E}{R} (\frac{1}{T1}-\frac{1}{T2}) \)

ln⁡\((\frac{k1}{10k1})\)=0.5ln⁡\((\frac{150}{300}) – \frac{E}{8.314}(\frac{1}{300} – \frac{1}{150}) \)

E = 4928 J/mol.

Right option is (b) Heterogeneous

The best EXPLANATION: The reactants are of DIFFERENT phases i.e. Hydrogen (Gas PHASE) and oil (Liquid phase). Ni catalyst (Solid) is also USED.

Right option is (C) time^-1 concentration^(1-n)

To explain I WOULD say: General expression for the RATE CONSTANT is time^-1 concentration^(1-n).

Right choice is (a) A variable volume reactor is the one in which the REACTION PROCEEDS by a CHANGE in number of MOLES at a given pressure and temperature.

Best explanation: The pressure is held constant as the volume VARIES. The variable volume systems are also termed as constant pressure systems.

The correct OPTION is (a) kmol/ML and 1/hr

The explanation: To GET the final units

-rA = \(\frac{1670[\frac{kmol}{ml}][\frac{kmol}{ml}]}{6+\frac{kmol}{ml}} \)

The units of CONSTANTS have to be 1/hr for 1670 and kmol/ml for 6.

Right CHOICE is (d) Reversible catalytic DECOMPOSITION of isopropylbenzene

To ELABORATE: C6H5CH(CH3)2 ←→ C6H6 + C3H6

Let’s represent this reaction SYMBOLICALLY asC ←→ B + P

the reaction follows the rate law-r’C = [k(PC – PBPP/KP)] / [1 + KCPC + KBPB] which is the LANGMUIR Hinshelwood model.

Right option is (d) 0.5

The EXPLANATION: The GENERAL equation for temperature dependency is k=koT^m \(e^{-\FRAC{E}{RT}} \)

If m = 0 → Arrhenius equation

m = 1 → transition state theory

m = 0.5 → COLLISION theory.

Correct OPTION is (a) ln⁡\((\frac{K1}{k2}) = \frac{E}{R} (\frac{1}{T2}-\frac{1}{T1}) \)

To elaborate: When we have two values of k and T

k1 = KO\(e^{-\frac{E}{RT1}}\) and k2 = ko\(e^{-\frac{E}{RT2}} \)

Modifying it gives

ln⁡(k1) = ln⁡(ko) – \((\frac{E}{R})\frac{1}{T1}\) and ln⁡(k2) = ln⁡(ko) – \((\frac{E}{R})\frac{1}{T2} \)

On further simplification we get ln⁡\((\frac{k1}{k2}) = \frac{E}{R} (\frac{1}{T2}-\frac{1}{T1}). \)

Correct choice is (d) –rA = K[CA^3 – CBCC^2/KC]

EASIEST explanation: Let’s say the rate constant for the forward reaction is k1 and for the backward reaction it is k2.

Rate of disappearance of A = k1CA^3

Rate of formation of A = k2CBCC^2

-rA = k1CA^3 – k2CBCC^2. We KNOW that KC = k1/k2. So, -rA = k[CA^3 – CBCC^2/KC].

Correct answer is (c) 82.31 KJ/mol

The explanation is: When we have TWO values of K and T

k1=koT1\(e^{-\FRAC{E}{RT1}} \) andk2=koT2\(e^{-\frac{E}{RT2}} \)

Modifying it gives

ln⁡(k1)=ln⁡(ko)+ln⁡(T1) – \((\frac{E}{R})\frac{1}{T1}\) and ln⁡(k2)=ln⁡(ko)+ln⁡(T2) – \((\frac{E}{R})\frac{1}{T2} \)

On further simplification we getln⁡\((\frac{k1}{k2})\)=ln⁡\((\frac{T1}{T2}) – \frac{E}{R}(\frac{1}{T1}-\frac{1}{T2}) \)

ln⁡\((\frac{0.002}{0.08})\)=ln⁡⁡\((\frac{273}{353})-\frac{E}{8.314}(\frac{1}{273} – \frac{1}{353}) \)

E = 34.377 KJ/mol.

Correct option is (d) Decay constant

To elaborate: Decay constant is actually a TYPE of rate constant, for a given decay REACTION. Solubility, association and DISSOCIATION constants are equilibrium constants. These are reaction quotients calculated at the stag of IONIC equilibrium w.r.t various ionic and non-ionic species present in a system.

Right option is (a) It reduces to irreversible form when PRODUCT CONCENTRATION is zero

Easy EXPLANATION: Rate LAW can be written in terms of both concentrations or partial pressures. The thermodynamic relationships are satisfied only at equilibrium. If the product concentration is zero, the rate of the backward reaction becomes zero and the rate law reduces to irreversible form.

The CORRECT ANSWER is (C) 2

Explanation: Order w.r.t A is 0.7 and B is 1.3.Hence, Overall order is 2.

Correct option is (a) True

The BEST I can EXPLAIN: ELEMENTARY reaction occurs in single reaction step with no intermediates and molecularity is the number of particles involved in the reaction.

Right option is (d) Temperature decreases in exothermic reactions

To EXPLAIN: EQUILIBRIUM constant is INDEPENDENT of the initial reactant concentration. It only depends on temperature. As temperature rises, equilibrium constant increases for an endothermic REACTION and decreases for an exothermic reaction. In both these CASES the reverse happens when the temperature falls.