Question

t(s) The decomposition of N2O5 can be described by the equation [N2O3] (M) 1.798 0 225 1.561 2N203 (soln) 4NO2 (soln) + O2(g) 526 1.292 Consider the data in the table for the reaction at 45 °C in carbon tetrachloride solution. 755 1.118 Given the data, calculate the average rate of reaction for each successive time interval. What is the average rate of reaction for the time interval from 0 s to 225 s? average rate of reaction: M/s What is the average rate of reaction for the time interval from 225 s to 526 s? average rate of reaction: M/s What is the average rate of reaction for the time interval from 526 s to 755 s? average rate of reaction: M/s

Answer 1

Answer:-

As we know that average rate of reaction is the change of concentration of reactants or products with respect to change of time.

A   $\rightarrow$ P

reactant product

then

average rate of reaction = - [A2 - A1] / [t2 - t1] = - $\Delta$ [A] / $\Delta$ [t] ------------------------(1)

where

- = minus sign indicates that concentration of reactant decrease with time (t)

A1 = concentration of reactant at time (t1)

A2 = concentration of reactant at time (t2)

t1 = initial time

t2 = final time

similarly

average rate of reaction = [P2 - P1] / [t2 - t1] =   $\Delta$[P] / $\Delta$ [t] ------------------------(2)

where

P1 = concentration of product at time (t1)

P2 = concentration of product at time (t2)

t1 = initial time

t2 = final time

From equation no. 1 and 2 we get

average rate of reaction =    - $\Delta$ [A] / $\Delta$ [t] =   $\Delta$[P] / $\Delta$ [t]

So

(I) -

Given:-

2N2O5(aq)   $\rightarrow$    4NO2(aq)    + O2(g)

reactant products

concentration of N2O5 at time (0 s) i.e ( A1 ) = 1.798 M

concentration of N2O5 at time (225 s ) i.e ( A2 ) = 1.561 M

initial time (t1) =  0 s

final time (t2) = 225 s

therefore according to formula

average rate of reaction = - [A2 - A1] / [t2 - t1]

average rate of reaction = - ( 1.561 M -  1.798 M ) / ( 225 s - 0 s)

average rate of reaction = - ( - 0.237 M / 225 s )

average rate of reaction = - ( - 0.00105 M /s )

average rate of reaction = 0.00105 M /s  (i.e the answer)

or

average rate of reaction = 1.05 $\times$ 10-3 M /s (i.e the answer)

similarly

(II)-

Given:-

2N2O5(aq)   $\rightarrow$    4NO2(aq)    + O2(g)

reactant products

concentration of N2O5 at time (225 s) i.e ( A1 ) = 1.561 M

concentration of N2O5 at time (526 s ) i.e ( A2 ) = 1.292 M

initial time (t1) =  225 s

final time (t2) = 526 s

according to formula

average rate of reaction = - [A2 - A1] / [t2 - t1]

average rate of reaction = - ( 1.292 M -  1.561 M ) / ( 526 s - 225 s)

average rate of reaction = - ( - 0.269‬ M / 301‬ s )

average rate of reaction = - ( - 0.0008936877‬ M /s )

average rate of reaction = 0.000894‬ M /s  (i.e the answer)

or

average rate of reaction = 8.94 $\times$ 10-4 M /s (i.e the answer)

similarly

(III) -

Given:-

2N2O5(aq)   $\rightarrow$    4NO2(aq)    + O2(g)

reactant products

concentration of N2O5 at time (526 s) i.e ( A1 ) = 1.292 M

concentration of N2O5 at time (755 s ) i.e ( A2 ) = 1.118 M

initial time (t1) =  526 s

final time (t2) = 755 s

according to formula

average rate of reaction = - [A2 - A1] / [t2 - t1]

average rate of reaction = - ( 1.118 M -  1.292 M ) / ( 755 s - 526 s)

average rate of reaction = - ( - 0.174‬‬ M / 229‬‬ s )

average rate of reaction = - ( - 0.00075982533‬‬ M /s )

average rate of reaction = 0.0007598 M /s  (i.e the answer)

or

average rate of reaction = 7.60 $\times$ 10-4 M /s (i.e the answer)