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Right answer is (b) Series reaction

Explanation: Series REACTIONS are a FORM of multiple reactions. For example, OXIDATION of methanol gives methanal, which in TURN gives methanoic acid.

Right CHOICE is (d) Oxidation of Nitric oxide

To elaborate: REACTION for oxidation of Nitric oxide is:

2NO + O2 → 2NO2

Termolecular REACTIONS are the ONES that involve the collision of three reactant MOLECULES.

Correct option is (B) Same as that of rate constant

Best EXPLANATION: The unit of frequency factor in Arrhenius equation is same as that of rate constant.

Arrhenius equation is, k = A e^-Ea/RT,

k: Rate constant

A: Frequency factor

The exponent TERM in Arrhenius equation gives an integer. Hence, unit of A DEPENDS on that of k.

Right answer is (d) Temperature, Pressure and CONCENTRATION of reactants

For explanation I would say: The REACTION RATE of gaseous phase reaction is DEPENDENT on all of them.

Correct choice is (d) Sum of the powers of the concentrations of all the reactants

To elaborate: The order of a reaction with RESPECT to a given substance is the power to which its CONCENTRATION term is raised in the rate equation. If there is more than one reactant MOLECULES involved in the reaction, then the order of the reaction is the sum of the powers of concentrations of all reacting SPECIES in the rate expression.

Right answer is (c) mol/s. m^3

Explanation: The REACTION rate is defined in terms of reaction volume for HOMOGENEOUS REACTIONS.

Right answer is (C) Ammonia SYNTHESIS

Easy EXPLANATION: Ammonia synthesis is a heterogeneous reaction. IRON is used as a catalyst in the synthesis of ammonia by Haber’s PROCESS.

The CORRECT choice is (c) Order of elementary reaction is an integer

Explanation: The order of an elementary reaction can never take fractional values. Elementary REACTIONS OCCUR in a single step. First order reactions can be elementary or NON- elementary.

Right choice is (c) CSTR

Easiest EXPLANATION: CSTR is operated in such a way that the REACTION mixture is perfectly MIXED. Hence, there are no spatial variations.

Correct ANSWER is (b) mol/s. G CATALYST

Explanation: Rate of reaction for a fluid-solid catalytic reaction is defined as the number of moles of A reacted per unit time per unit mass of catalyst.

The correct option is (d) a+B

Easiest explanation: Sum of the powers of the CONCENTRATIONS of the reactants, A and B is the ORDER of reaction. For the reaction (-RA) = kCA^a.CB^b, order = (a+b).

The correct choice is (a) HYDROLYSIS of an ester to a carboxylic ACID using water

Explanation: Pseudo first order reactions are the ones in which the concentration of one of the reactants is used in excess to convert higher order reactions to 1ST order. As water is used as SOLVENT in esterification REACTION, its concentration is in huge excess compared to the ester. Thus, the reaction is pseudo first order for the ester.

Right choice is (a) A + B → R; (-rA) = k CACB

Explanation: ELEMENTARY reactions are the ones in which rate equation corresponds to stoichiometry. For the REACTION A + B → R, 1 MOLE of A and 1 mole of B TAKE part in the reaction. Hence, the rate equation has to be

(-rA) = k CA^1CB^1.

Correct OPTION is (a) True

Easy explanation: From design eqn \(\frac{dFi}{DV}\) = ri. The reaction rate doesn’t DEPEND on shape of the reactor.

The correct answer is (B) RATE of disappearance of A

The explanation: rA indicates the rate of FORMATION of A whereas –rA indicates the rate of disappearance of A.

Right OPTION is (a) (time)^-1

The explanation: Rate of 1st order reaction, (-rA) = kCA^n

Unit of rate = \(\FRAC{MOL}{m^3×s}\)

Concentration, CA is in \(\frac{mol}{m^3} \)

Hence, unit of K is \(\frac{\frac{mol}{m^3×s}}{\frac{mol}{m^3}}\) = (sec)-1.

Correct OPTION is (d) \(\frac{conc^{1-n}}{time^{-1}} \)

To explain I would SAY: For any ORDER n, (-RA) = kCA^n

\(\frac{mol}{m^3×s} = k.(\frac{mol}{m^3})^n \)

Hence the unit of k is \(\frac{conc^{1-n}}{time^{-1}}. \)

Correct option is (b) an intensive property

For EXPLANATION: Chemical reaction RATE DEPENDS on TEMPERATURE and concentration. Hence, it is an intensive property.

Correct CHOICE is (a) Non chain reaction

Best explanation: In non chain reactions, REACTANTS form intermediate in the first STEP. The intermediates in turn form the products.

The correct answer is (b) Free radical, chain reaction MECHANISM

To elaborate: FORMATION of HBR occurs via free radical mechanism. The Br. radical is first FORMED. It then COMBINES with H2 to form HBr and another Br. radical.

Right choice is (c) Chemical KINETICS

For EXPLANATION: Chemical Kinetics is the study of rate of chemical reaction and the effect of parameters like temperature, PRESSURE, CONCENTRATION, etc. on reaction RATES. Kinetic studies help in obtaining information about reaction mechanism and transition states.

Right answer is (b) \(\frac{dNi}{dt}\) = ri V

Best EXPLANATION: GENERAL mole balance for batch reactor is \(\frac{dNi}{dt} = \int_0^V\)ri dV. For perfectly mixed batch REACTORS there are no spatial variations and above equation can be modified as

ri = \(\frac{1}{V} \frac{dNi}{dt}. \)

Correct option is (d) Rate of moles of ‘i’ in – Rate of moles of ‘i’ CONSUMED by REACTION – Rate of moles of ‘i’ out = Rate of moles of ‘i’ accumulated

To elaborate: Governed by PRINCIPLES of CONSERVATION of mass and ENERGY the following equation is the basic equation in Chemical engineering for design of all process units.

IN – OUT + Generation – Consumption = Accumulation.

The CORRECT option is (d) Zero order REACTION

To elaborate: Zero order reaction is the one in which RATE does not DEPEND on concentration.

(-r) = k

k → Rate constant

The CORRECT answer is (c) REACTIONS in rocket engines

Easy explanation: The rate of REACTION in rocket engines is in the range 10^5-10^8. The ORDER of decrease in rates is, Reactions in rocket engines > Reactions in coal furnaces > Gas reactions in porous CATALYSTS > Cellular reactions.

Correct answer is (c) AMOUNT of product

Easy EXPLANATION: The rate of the REACTION can be expressed in terms of UNIT VOLUME of reacting fluid, based on unit interfacial area and unit volume of solid. The amount of product formed has no influence on the reaction rate.

The correct CHOICE is (C) an algebraic eqn

Explanation: RATE LAW is experimentally determined. It is a product of rate CONSTANT and algebra function of concentration.

Right answer is (C) A CONCENTRATION dependent term and a TEMPERATURE dependent term

Easy explanation: (-rA) = kC^n,

Where,

k: Rate constant

C: Concentration

Rate constant, k is a FUNCTION of temperature.

Correct choice is (a) \(\frac{MOLES \, of \, product \, formed}{Volume \, of \, fluid×Time} \)

Explanation: RATE of the reaction is the number of moles of the REACTANT component disappearing PER UNIT volume per unit time. The moles of the product formed are the number of moles of the reactant species disappearing during the course of reaction.

Correct answer is (c) \(\frac{-r_A}{a}\)=\(\frac{-r_B}{B}\) ≤ \(\frac{r_R}{r} \)

The EXPLANATION is: The rates of degradation of reactants and formation of product are RELATED to each other as \(\frac{-r_A}{a} = \frac{-r_B}{b} = \frac{r_R}{r} \), where a, b and c DENOTE the stoichiometry. The rate of disappearance of any reactant in TURN is the rate of formation of products.

Right choice is (a) A catalyst remains unchanged in mass at the END of the REACTION

The BEST I can explain: A catalyst remains unchanged in mass and chemical composition at the end of the reaction. Catalyst cannot initiate the reaction. Catalyst cannot CHANGE the position of EQUILIBRIUM.

Correct option is (a) 10^-3-10^-4

To elaborate: The cellular reactions in LIVING ORGANISMS occur very SLOWLY. Hence, the rate is of the order 10^-3-10^-4 MOLES DISAPPEARING/(m^3.s).

Right choice is (a) MOLECULARITY

To explain: Molecularity of an elementary REACTION is the number of molecules of the reactant taking part in the reaction. Order of a reaction is the sum of the powers of the CONCENTRATIONS of all the reactants. Unimolecular reactions involve only one reactant. Rate of a reaction is the number of moles of the reactant component disappearing per unit VOLUME per unit time.