`A_(2)B` is an ideal gas , which decompase according f to the equation : `A_(2) B to A_(2) + (1)/(2)B_(2)` . At start , the initial pressure is 100 mm Hg and after 5 minutes , the pressure is 120 mm Hg. What is the average rate of decomposition of `A_(2)B` ? Assume T and V are constant .

Explanation

The decomposition reaction of gaseous `A_(2)B` is given as
`A_(2)B to A_(2) +(1)/(2)B_(2)`
`100" 0" "0` at start of the reaction .
100 - 2x + 2x + x = 100 + x = 120 mm.
x = 20 mm or 2x = 40 mm
The decrease in pressure of reactant substant `A_(2)B` in 5 mint is 40 mm.
The rate decomposition of `A_(2)B = (40)/(5) = 8 mm min^(-1)`
` =0.133 mm s^(-1)`