Question

Calculate the initial rate for the formation of c at 25 ∘c, if [a]=0.50m and [b]=0.075m

Answer 1

The initial rate for the formation of C at 25°C, if [A]=0.50M and [B]=0.075M is 0.022 M/s

Further explanation

Calculate the initial rate for the formation of C at 25°C, if [A]=0.50M and [B]=0.075M. Express your answer to two significant figures and include the appropriate units. Consider the reaction

A+2B → C

whose rate at 25°C was measured using three different sets of initial concentrations as listed in the following table:

Trial                    [A]                    [B]                    Rate

                         (M)                   (M)                    (M/s)

1                       0.20                 0.030                1.4 x 10 - 3  

2                       0.20                 0.060                2.9 x 10      - 3

3                       0.40                 0.030                5.8 x 10       - 3

$rate = k[A]^x[B]^y$

We will take a look on 1st and 3rd data.

$[A]^x \\ \frac{5.8*10^-3 }{1.4*10^-3} = \frac{ 0.40}{0.20^x} \\4.14 = 2^x\\log (4.14) = x log 2\\x = 2$

$[B]^y\\ \frac{2.9*10^-3}{1.4*10^-3} = \frac{0.060}{0.030^y} \\2.07 = 2^y\\y = 1$

because

$log (2.07) = y log (2)\\y= 1$

$1.4*10^-3 = k[0.20]^2[0.030]^1\\1.4*10^-3 = k[0.0012]\\k = 1.7$

$k$ have units of $M^{-n+1}* s^{-1}$

so

$k = 1.7 M^{-3+1}* s^{-1}\\k = 1.7 M^{-2}* s^{-1}\\Rate = k[A]^2[B]\\Rate = 1.7 M^{-2}* s^{-1}[0.50]^2[0.075]\\Rate = 0.022 M* s^{-1}$(2 significant values)

Learn more

1. Learn more about units brainly.com/question/1205588
2. Learn more about the initial rate brainly.com/question/1503519
3. Learn more about two significant figures brainly.com/question/12445529

Answer details

Grade:  9

Subject:  chemistry

Chapter:  chemical kinetics

Keywords: the initial rate, formation, c, time, M

Answer 2

Rate = k * [A]^2 * [B]^1 

Use the data from any trial to calculate k. 

k = (rate)/([A]^2 * [B]^1) 

E.g., for Trial 1, we have 

rate = 3.0×10−3 M/s 
[A] = 0.50 M 
[B] = 0.010 M 

Plug those numbers in and crank out the answer. 

Now with the calculated value of k, calculate the initial rate for [A] = 0.50 M and [B] = 0.075 M 

rate = k * [A]^2 * [B]^1 

k = calculated value 
[A] = 0.50 M 
[B] = 0.075 M