Question

In a first order reaction the concentration of the reactant is reduced from 0.6 mol/litre to 0.2 mol/litre in 5 minute. Calculate the rate constant of the reaction?

Answer 1

Given :

➛ Initial conc. = 0.6mol/L

➛ Final conc. = 0.2mol/L

➛ Time = 5min

➛ Order of reaction : one

To Find :

➳ Rate constant of the reaction.

Formula :

✭ Formula of rate constant for first order reaction is given by

$\dashrightarrow\:\underline{\boxed{\bf{\purple{k=\dfrac{2.303}{t}\times log\dfrac{a}{a'}}}}}$

where,

፨ k denotes rate constant

፨ t denotes time

፨ a denotes initial concentration

፨ a' denotes final concentration

Conversion :

⎆ 1min = 60s

⎆ 5min = 5×60 = 300s

Calculation :

⇒ $\sf{k=\dfrac{2.303}{300}\times log\dfrac{0.6}{0.2}}$

⇒ $\sf{k=0.007676\times log3}$

⇒ $\sf{k=0.007676\times 0.477}$

⇒ $\bf{k=3.66\times 10^{-3}\:s^{-1}}$

Answer 2

$\huge\sf\pink{Answer}$

☞ $\sf k = 3.66\times 10^{-3} s^{-1}$

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$\huge\sf\blue{Given}$

✭ Initial Concentration = 0.6 mol/l

✭ Final Concentration = 0.2 mol/l

✭ Time = 5 min = 5×60 = 300 seconds

✭ The order of the Reaction = first

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$\huge\sf\gray{To \:Find}$

◈ Rate constant of the Reaction?

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$\huge\sf\purple{Steps}$

We know that,

$\underline{\boxed{\sf K = \dfrac{2.303}{t} \times log \dfrac{a}{a'}}}$

Substituting the given values,

➳ $\sf k = \dfrac{2.303}{300} \times log\dfrac{0.6}{0.2}$

➳ $\sf k = 0.007676 \times log3$

➳ $\sf k = 0.007676 \times 0.477$

➳ $\sf\orange{k = 3.66\times 10^{-3} s^{-1}}$

$\rule{170}3$