di-tert-butyl peroxide, (CH3)3COOC(CH3)3 decomposes into 2(CH3)2CO and C2H6

The reaction takes place in a reactor of 400mL volume at 150 C. All species are in the gaseous state. The gas phase consists initially of nitrogen with a partial pressure of 5 mmHg and di-tert -butyl peroxide with a partial pressure of 170 mmHg. The following table gives the total pressure measured at consecutive times.

Calculate the extent of reaction and the extent of reaction density.

Time Total pressure min mmHg 0 173.5 2 187.3 3 193.4 5 205.3 6 211.3