Q1 · 2005-2021 · 2 marks
Which of the following statements is NOT correct for a catalyst?
- (a) It increases the rate of a reaction
- (b) It is not consumed in the course of a reaction
- (c) It provides an alternate pathway for the reaction
- (d) It increases the activation energy of the reaction
Show answer
Answer: (d)
Report an error in ABC26PH0338
Q2 · 2005-2021 · 2 marks
The value of the rate constant for the gas phase reaction \mathrm{2NO_2 + F_2 \rightarrow 2NO_2F} is 38\ \mathrm{dm^3\,mol^{-1}\,s^{-1}} at 300 K. The order of the reaction is
Show answer
Answer: (c)
Report an error in ABC26PH0339
Q3 · 2005-2021 · 2 marks
The rate constant of two reactions as temperature T are k_{1}(T) and k_{2}(T) and the corresponding activation energies are E_{1} and E_{2} with E_{2}>E_{1}. When temperature is raised from T_{1} and T_{2}, which one of the following relations is correct?
- (a) \frac{k_{1}(T_{2})}{k_{1}(T_{1})}=\frac{k_{2}(T_{2})}{k_{2}(T_{1})}
- (b) \frac{k_{1}(T_{2})}{k_{1}(T_{1})}>\frac{k_{2}(T_{2})}{k_{2}(T_{1})}
- (c) \frac{k_{1}(T_{2})}{k_{1}(T_{1})}\geq\frac{k_{2}(T_{2})}{k_{2}(T_{1})}
- (d) \frac{k_{1}(T_{2})}{k_{1}(T_{1})}<\frac{k_{2}(T_{2})}{k_{2}(T_{1})}
Show answer
Answer: (d)
Report an error in ABC26PH0343
Q4 · 2005-2021 · 2 marks
For the reaction \mathrm{2X_3 = 3X_2}, the rate of formation of \mathrm{X_2} is:
- (a) 3(-d[\mathrm{X_3}]/dt)
- (b) \frac{1}{2}(-d[\mathrm{X_3}]/dt)
- (c) \frac{1}{3}(-d[\mathrm{X_3}]/dt)
- (d) \frac{3}{2}(-d[\mathrm{X_3}]/dt)
Show answer
Answer: (d)
Report an error in ABC26PH0344
Q5 · 2005-2021 · 2 marks
In a homogeneous catalytic reaction, 1.0 M of a substrate and 1.0\,\mu\mathrm{M} of a catalyst yields 1.0 mM of a product in 10 seconds. The turnover frequency (TOF) of the reaction (\mathrm{s}^{-1}) is
- (a) 10^{-2}
- (b) 10^{2}
- (c) 10^{-3}
- (d) 10^{3}
Show answer
Answer: (b)
Report an error in ABC26PH0345
Q6 · 2005-2021 · 2 marks
For the reaction given below, the relaxation time is 10^{-6}\,\mathrm{s}. Given that 10% of A remains at equilibrium, the value of k_1\left(\mathrm{s}^{-1}\right) is A \underset{k_{-1}}{\stackrel{k_1}{\rightleftharpoons}} B
- (a) 9 \times 10^5
- (b) 10^{-5}
- (c) 10^5
- (d) 9 \times 10^{-5}
Show answer
Answer: (a)
Report an error in ABC26PH0346
Q7 · 2005-2021 · 2 marks
For the parallel first order reaction shown below 
the value of k_1 is 1 \times 10^{-4}\ \mathrm{s^{-1}}. If the reaction starts from X, the ratio of the concentrations of Y and Z at any given time during the course of the reaction is found to be \frac{[\mathrm{Y}]}{[\mathrm{Z}]} = \frac{1}{4}. The value of k_2 is: - (a) 1 \times 10^{-4}\ \mathrm{s^{-1}}
- (b) 2.5 \times 10^{-5}\ \mathrm{s^{-1}}
- (c) 4 \times 10^{-4}\ \mathrm{s^{-1}}
- (d) 4 \times 10^{4}\ \mathrm{s^{-1}}
Show answer
Answer: (c)
Report an error in ABC26PH0348
Q8 · 2005-2021 · 2 marks
The specific rate constant of decomposition of compound is represented by \text { Ink }=5.0-\frac{12000}{\mathrm{~T}}
The activation energy of decomposition for this compound at 300 K is - (a) 24 kcal/mole
- (b) 12 kcal/mole
- (c) 24 cal/mole
- (d) 12 cal/mole Statement for Linked Answer Q. 54 and Q. 55: In the m vs T diagram for different phases of the same substance at one atmospheric pressure, the lines \mathrm{A}, \mathrm{B} and C compound to
Show answer
Answer: (c)
Report an error in ABC26PH0353
Q9 · 2005-2021 · 2 marks
For a given first order reaction, the reactant reduces to 1/4^{\text{th}} its initial value in 10 minutes. The rate constant of the reaction is:
- (a) 0.1386\ \mathrm{min^{-1}}
- (b) 0.0693\ \mathrm{min^{-1}}
- (c) 0.1386\ \mathrm{mol\,L^{-1}\,min^{-1}}
- (d) 0.0693\ \mathrm{mol\,L^{-1}\,min^{-1}}
Show answer
Answer: (a)
Report an error in ABC26PH0356
Q10 · 2005-2021 · 2 marks
For a reaction involving two steps given below First step: \mathrm{G \rightleftharpoons 2H}
Second step: \mathrm{G + H \rightarrow P}
assume that the first step attains equilibrium rapidly. The rate of formation of P is proportional to - (a) [\mathrm{G}]^{1/2}
- (b) [\mathrm{G}]
- (c) [\mathrm{G}]^{2}
- (d) [\mathrm{G}]^{3/2}
Show answer
Answer: (d)
Report an error in ABC26PH0360
Q11 · 2005-2021 · 2 marks
Consider the reaction, 2\mathrm{C}(\mathrm{s})+\mathrm{O}_{2}(\mathrm{g})\rightleftharpoons 2\mathrm{CO}(\mathrm{g}) at equilibrium, The equilibrium can be shifted towards the forward direction by
- (a) Increasing the amount of carbon in the system
- (b) Decreasing the volume of the system
- (c) Decreasing the pressure of the system
- (d) Increasing the temperature of the system
Show answer
Answer: (c)
Report an error in ABC26PH0362
Q12 · 2005-2021 · 2 marks
The rate constant of a reaction is 1.25 \times 10^{-4}\ \mathrm{mol\,L^{-1}\,s^{-1}}. If the initial concentration of the reactant is 0.250 \mathrm{mol\,L^{-1}}, the total time (in second) required for complete conversion is ____
Show answer
Answer: 2000
Report an error in ABC26PH0370
Q13 · 2005-2021 · 2 marks
The dependence of rate constant k on a temperature T (in K) of a reaction is given by the expression \ln k = [(-5000\ \mathrm{K})/T] + 10
The activation energy of the reaction (in \mathrm{kJ\ mol^{-1}}) is ____ (up to two decimal places) Show answer
Answer: 41.57
Report an error in ABC26PH0371
Q14 · 2005-2021 · 2 marks
Under physiological conditions, the conversion of \mathrm{CO_2} to bicarbonate ion by carbonic anhydrase enzyme (MW = 30,000 \mathrm{g\,mol^{-1}}) has a turnover number of 4.00 \times 10^{5}\ \mathrm{s^{-1}}. The minimum amount of enzyme (in \mug) required to convert 0.44 g of \mathrm{CO_2} to bicarbonate ions in 100 seconds is ________ (up to two decimal places)
Show answer
Answer: 7.5
Report an error in ABC26PH0373
Q15 · 2005-2021 · 2 marks
According to Eyring state theory for a bimolecular reaction, the activated complex has
- (a) no vibrational degrees of freedom
- (b) vibrational degrees of freedom but they never participate in product formation
- (c) one high frequency vibration that leads to product formation
- (d) one low frequency vibration that leads to prodcut formation
Show answer
Answer: (c)
Report an error in ABC26PH0374
Q16 · 2005-2021 · 2 marks
Consider the following two parallel irreversible first order reactions at temperature T, 
where k_1 and k_2 are the rate constants and their values are 5 \times 10^{-2} and 15 \times 10^{-2}\ \mathrm{min^{-1}} respectively, at temperature T. If the initial concentration of the reactant 'P' is 4\ \mathrm{mol\,L^{-1}}, then the concentration of product 'R' after 10 min of reaction is ____ \mathrm{mol\,L^{-1}}. (Round off to two decimal places) (Assume only P is present at the beginning of the reaction) Show answer
Answer: 2.59
Report an error in ABC26PH0378
Q17 · 2005-2021 · 2 marks
In Freundlich isotherm, a linear relationship is obtained in the plot of (\theta = surface coverage and p = partial pressure of the gas)
- (a) \theta vs p
- (b) \ln(\theta) vs \ln(p)
- (c) \ln(\theta) vs p
- (d) \theta vs \ln(p)
Show answer
Answer: (b)
Report an error in ABC26PH0484
ABC Chemistry
CSIR NETChemical Science Coaching
GATEChemical Science Preparation
IIT JAMM.Sc Entrance Coaching
CUET PGPost Graduate Entrance
Class 11 ChemistryLive online
Class 12 ChemistryLive onlineStudy LibraryPrevious year papers171 official papers · JAM, NET, GATE, CUETTopic-wise decks32 PDF + PPTX decks, freeBuild your own PDFChoose exam → topic → downloadStudy materialUnit-wise notes for the batchesTest papers 8–12School practice papersDreamer's QuizWeekly chemistry quizQuestions by topicRead online with verified answersSearchTopics, courses and articlesExam guidesSyllabus, pattern, eligibilityBlogChapter notes and PYQ analysisBooks by ABPeriodic table and data bookGreat Home TutorPh.DAboutContactBlogsQ&A▶️ YouTubeEnquiryBook a free demoCall +91 92121 42427