Question

Determine the rate law for the reaction 2A + 3B >> C

[A] (M) = 0.15, 0.30, 0.30

[B] (M)= 0.30, 0.30, 0.90

Rate (mol/Ls)= 0.1259, 0.0159, 0.0476

Please show steps and work for study purposes! Thanks in advance!

Answer 1

The data given is,

Rate ... [A] (M) ..   [B] (M)

0.1259 .. 0.15 ..... 0.30 -------------------- (1)

0.0159....0.30 ..... 0.30 --------------------- (2)

0.0476 ... 0.30......0.90 -------------------- (3)

Let the rate expression be given as follows,

Rate = K [A]^x [B]^y

From (1), (2) and (3)

0.1259 = K (0.15)^x * (0.30)^y -------------------- (1)

0.0159 = K (0.30)^x * (0.30)^y ------------------ (2)

0.0476 = K (0.30)^x * (0.90)^y ------------------ (3)

Dividing (2) by (1),

0.1263 = 2^x

=> x = - 3

'x' cannot be negative, Therefore, there is some error with the data.

Dividing (3) by (2),

3 = 3^y

=> y = 1

Rate = K [A]^-3 [B]