Question

The following data are obtained at 0°C in a constant-volume batch reactor using pure gaseous

Time, min	0	2	4	6	8	10	12	14	∞
Partial pressure of A, mm Hg	760	600	475	390	320	275	240	215	150

The stoichiometry of the decomposition is A → 2.5 R. Find a rate equation which satisfactorily represents this decomposition.

Answer 1

The reaction is given as,

The rate of a reaction can be written as,

Where is the rate constant.

In terms of partial pressure of we can write,

So ,

Taking ln on both sides we can see,

This means that if we draw a graph of vs we will get a graph of slope and a y axis intercept of

So for finding , first we have to draw the graph of vs from the data given above,

We will do it in excel,

So adding the trendline we got the equation as for   vs as,

So, we can find as,

Now we will draw the graph of   vs ,

Now the equation can be written as,

Comparing both the equations we get,

and,

So the rate equation can be written as,

The temperature is given as,

So the rate equation can be written as,

Here is in mmHg and is in