Test Index

NCERT Class XII Chemistry
Chapter - Chemical Kinetics
Questions with Solutions

© examsnet.com
Question : 4 of 39
Marks: +1, -0
The decomposition of dimethyl ether leads to the formation of CH4,H2\mathrm{CH}_4, \mathrm{H}_2 and CO and the reaction rate is given by
          \; \; \; \; \;Rate =k[CH3 OCH3]32=k [ \mathrm{CH}_3 \ \mathrm{OCH}_3 ]^{\frac{3}{2}}
The rate of reaction is followed by increase in pressure in closed vessel, sothe rate can also be expressed in terms of the partial pressure of dimethylether, i.e.,
          \; \; \; \; \;Rate =k[pCH3 OCH3]32=k [ p_{\mathrm{CH}_3} \ \mathrm{OCH}_3 ]^{\frac{3}{2}}
If the pressure is measured in bar and time in minutes, then what are theunits of rate and rate constants ?
Solution:  
In terms of pressure,
Units of rate = bar min−1^{-1}
Units of k=Rate(pCH3 OCH3)32k= \frac{ \text{Rate} }{ \left( p_{\mathrm{CH}_3 \ \mathrm{OCH}_3} \right)^{\frac{3}{2}} }
=bar min−1bar32=\frac{ \mathrm{bar} \ \mathrm{min}^{-1} }{ \mathrm{bar}^{\frac{3}{2}} }
=bar−12 min−1=\mathrm{bar}^{-\frac{1}{2}} \ \mathrm{min}^{-1}
© examsnet.com
Go to Question:
Prev Question
Next Question