# for A+B GIVES RISE TO C+D WHEN[A] ALONE IS DOUBLED ,RATE GETS DOUBLED BUT WHEN ALONE IS INCREASED BY 9 TIMES RATE GETS TRIPLED THEN ORDER OF REACTION IS

__B' alone is increased by 9 times...__

If concentration of A is doubled and yet it still gives only double the reaction rate. This means stoichiometric co efficient of A should be 1 itself.

dR/dT = k[A]

^{x}[B]

^{y}...1

new eqn

2*dR/dT = k[2A]

^{x}[B]

^{y}....2

On solving 1 and 2, we get,

2 = 2

^{x}

x=1.

Now similarily for the second circumstance :

dR/dT = k[A]

^{x}[B]

^{y}...1

3*dR/dT = k[A]

^{x}[9B]

^{y}....2

On solving 1 and 2 we get,

3=9

^{y}

9

^{1/2}= 9

^{y}

y=1/2

So the order of the reaction would be 1 + 1/2 = 3/2 = 1.5

The order can be in fraction .

Hope this helped! :))