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NCERT Class XII Chemistry
NCERT Class XII Chemistry
Chapter - Chemical Kinetics
Questions with Solutions
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Question : 22 of 39
Marks:
+1,
-0
The rate constant for the decomposition of at various temperatures is given below:
Draw a graph between ln k and 1/T and calculate the value of A and EPredict the rate constant at 30°C and 50°C.
| T/°C | 0 | 20 | 40 | 60 | 80 |
| 0.0787 | 1.70 | 25.7 | 178 | 2140 |
Solution:
The values of rate constants for the decomposition of N2O5 at varioustemperatures are given below :
Slope of the line = tan θ slope or, or, antilog or,Value of rate constant k at 303 K and 323 K can be obtained from graph.First of all ln k is obtained corresponding toand and thenk is calculated.
| T(°C) | T (K) | 1/T | k (s) | ln k (= 2.303 log k) |
| 0 | 273 | 3.6 ×10 | 7.87 ×10 | -14.06 |
| 20 | 293 | 3.4 ×10 | 1.70×10 | -10.98 |
| 40 | 313 | 3.19 ×10 | 25.7 ×10 | -8.266 |
| 60 | 333 | 3.00 ×10 | 178×10 | - 6.332 |
| 80 | 353 | 2.8 ×10 | 2140 ×10 | -3.844 |

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