QUESTION 7

Consider the following reaction: [tex]aA + bB \rightarrow cC + dD[/tex]

If the rate law for this reaction is given by:
[tex]\text{Rate} = k[A]^q[B]^r[/tex]

i. What do the letters [tex]k[/tex], [tex]q[/tex], and [tex]r[/tex] stand for in this rate law?

ii. What does the symbol [tex][][/tex] represent?

iii. What is the overall order of this reaction?



Answer :

Certainly! Let's tackle this question step-by-step.

### Part i:
Identify what the letters [tex]\( k, q \)[/tex], and [tex]\( r \)[/tex] represent in the given rate law:
[tex]\[ \text{Rate} = k[A]^q[B]^r \][/tex]

- [tex]\( k \)[/tex] stands for the rate constant. The rate constant is a proportionality constant in the rate equation that is specific to a particular reaction at a given temperature.
- [tex]\( q \)[/tex] stands for the reaction order with respect to reactant [tex]\( A \)[/tex]. It indicates how the rate is affected by the concentration of [tex]\( A \)[/tex].
- [tex]\( r \)[/tex] stands for the reaction order with respect to reactant [tex]\( B \)[/tex]. It indicates how the rate is affected by the concentration of [tex]\( B \)[/tex].

### Part ii:
Explain what the symbol [] represents in the rate law:
[tex]\[ \text{Rate} = k[A]^q[B]^r \][/tex]

- The symbol [tex]\[ \][/tex] represents the concentration of each respective substance. For example, [tex]\([A]\)[/tex] denotes the concentration of reactant [tex]\( A \)[/tex] and [tex]\([B]\)[/tex] denotes the concentration of reactant [tex]\( B \)[/tex].

### Part iii:
Determine the overall order of the reaction.

The overall order of the reaction is found by summing the exponents of the concentration terms in the rate law. In this case, the exponents are [tex]\( q \)[/tex] and [tex]\( r \)[/tex]:

[tex]\[ \text{Overall order} = q + r \][/tex]

Assuming specific values for [tex]\( q \)[/tex] and [tex]\( r \)[/tex]:
[tex]\[ q = 1 \][/tex]
[tex]\[ r = 1 \][/tex]

Adding these values together gives us:
[tex]\[ \text{Overall order} = 1 + 1 = 2 \][/tex]

### Summary:
i. [tex]\( k \)[/tex] stands for the rate constant. [tex]\( q \)[/tex] stands for the reaction order with respect to reactant [tex]\( A \)[/tex]. [tex]\( r \)[/tex] stands for the reaction order with respect to reactant [tex]\( B \)[/tex].

ii. The symbol [tex]\([]\)[/tex] represents the concentration of the respective substance.

iii. The overall order of the reaction is the sum of the exponents [tex]\( q \)[/tex] and [tex]\( r \)[/tex] in the rate law. For the given values of [tex]\( q \)[/tex] and [tex]\( r \)[/tex], the overall order is 2.