Join WhatsApp Icon JEE WhatsApp Group
Question 75

If the half life of a first order reaction is 6.93 minutes then the time required for completion of 99% of the reaction will be _______ minutes. (Given: log 2 = 0.3010)


Correct Answer: 46.06

Step 1: Calculate the rate constant $$(k)$$.

For, first order reaction the rate constant $$(k)$$ is related to $$t_{1/2}$$ by this formula:

$$t_{1/2}=\frac{0.693}{k}$$

since, 

$$t_{1/2}=6.93$$

$$k=\frac{0.693}{6.93}=0.1\ \min^{-1}$$

Step 2: Calculate time for 99% Completion

The integrated rate law for a first-order reaction give us to solve for time $$(t)$$:

$$t=\frac{2.303}{k\ }\log\left(\frac{\left[A_o\right]}{\left[A_t\right]}\right)$$

For 99% completion, 1% of the reactant remains.

Let's assume the initial concentration $$[A]_0 = 100$$, then the final concentration $$[A]_t = 1$$:

$$t=\frac{2.303}{0.1}\log\left(\frac{100}{1}\right)$$

$$t=\frac{2.303}{0.1}\times\ 2$$

$$t=23.03\times\ 2$$

$$t=46.06$$ minutes

Therefore, the time required for completion of 99% of the reaction will be 46.06 minutes.

Get AI Help

Video Solution

video

Create a FREE account and get:

  • Free JEE Mains Previous Papers PDF
  • Take JEE Mains paper tests

JEE Quant Questions | JEE Quantitative Ability

JEE DILR Questions | LRDI Questions For JEE

JEE Verbal Ability Questions | VARC Questions For JEE

Free JEE Topicwise Questions

JEE Rotational MotionJEE Units & MeasurementsJEE Atomic StructureJEE GravitationJEE Periodic Table & PeriodicityJEE StatisticsJEE Inverse Trigonometric FunctionsJEE Magnetism & Magnetic MaterialsJEE Sequences & SeriesJEE MatricesJEE Alternating CurrentsJEE Carboxylic AcidsJEE Permutations & CombinationsJEE Work, Energy & PowerJEE Electromagnetic InductionJEE Electronic DevicesJEE d and f-Block ElementsJEE Chemical KineticsJEE Heat TransferJEE Three Dimensional GeometryJEE Magnetic Effects of CurrentJEE Hydrocarbons - AromaticJEE Electromagnetic WavesJEE Aldehydes & KetonesJEE Hydrocarbons - AlkanesJEE Applications of DerivativesJEE EquilibriumJEE Indefinite IntegrationJEE Chemical ThermodynamicsJEE ElectrochemistryJEE ProbabilityJEE BiomoleculesJEE Continuity & DifferentiabilityJEE Kinetic Theory of GasesJEE Vector AlgebraJEE Hydrocarbons - AlkynesJEE Differential EquationsJEE Current & ResistanceJEE Straight LinesJEE WavesJEE Redox ReactionsJEE Hydrocarbons - AlkenesJEE DeterminantsJEE SolutionsJEE Ray OpticsJEE Dual Nature of Matter & RadiationJEE Chemical Bonding & Molecular StructureJEE Complex NumbersJEE Sets, Relations & FunctionsJEE Electric Charges & FieldsJEE Laws of MotionJEE Fluid MechanicsJEE Basic Concepts in ChemistryJEE Trigonometric FunctionsJEE LimitsJEE Laws of ThermodynamicsJEE Kinematics - 2D MotionJEE p-Block Elements (Groups 13-18)JEE Simple Harmonic MotionJEE Electric Potential & CapacitanceJEE Coordination CompoundsJEE JEE 2D GeometryJEE CirclesJEE Definite IntegrationJEE EMF & Circuit AnalysisJEE Surface TensionJEE Atoms & NucleiJEE Laboratory Experiments - XIJEE Number SystemJEE Basic Principles of Organic ChemistryJEE Wave OpticsJEE Quadratic EquationsJEE Alcohols, Phenols & EthersJEE Organic Compounds with HalogensJEE DifferentiationJEE Conic SectionsJEE Nitrogen-Containing CompoundsJEE ElasticityJEE Practical Organic ChemistryJEE Kinematics - 1D MotionJEE Purification & CharacterisationJEE Binomial Theorem
Ask AI