1. All the following are reaction rate units except
a. ∆M s-1
b. -∆M s-1
c. ∆V M-1 ***
d. ∆M min-1
2. Determine the overall reaction order for the reaction whose rate law is as follows: rate=k[O3][ClO]:
a. 0
b. 1 ***
c. 2
d. 3
3. 0.03 moles are produced in a 1.5-L vessel in 3 seconds. The initial reaction rate is
a. 0.007 M/s
b. 0.014 M/s ***
c. 0.14 M/s
d. 200 M/s
I need help. I don't understand reaction orders.
2. The order of a reaction is the sum of the exponents for each reactant in the rate equation. I see a 1 for each so it is 1st order with respect to ClO^- and 1st order with respect to O3 and 2nd order overall.
3. Note that the units for each answer is the same; i.e., M/s which is mols/L*s.
You have 0.03 mols and 1.5 L so that is 0.03 mols/1.5L = 0.02 mol/L and that is for 3 sec so 0.02 mol/L*s = 0.02/3 = 0.00667 which rounds to 0.007 M/s to one significant figure.
1. To determine the correct answer for this question, we need to understand the units of reaction rates. The general formula for the rate of a reaction is:
Rate = ∆[R] / ∆t,
where ∆[R] represents the change in concentration (or pressure for gases) of the reactant or product, and ∆t represents the change in time.
Now, let's analyze each answer choice:
a. ∆M s-1: This is a valid unit for reaction rate, representing the change in concentration (M) per unit time (s).
b. -∆M s-1: This is also a valid unit for reaction rate, representing the negative change in concentration (M) per unit time (s).
c. ∆V M-1: This is an incorrect unit for reaction rate. It represents the change in volume (V) per unit concentration (M).
d. ∆M min-1: This is a valid unit for reaction rate, representing the change in concentration (M) per unit time (min).
Therefore, the correct answer is c. ∆V M-1, since it does not represent a valid unit for reaction rates.
2. To determine the overall reaction order for the given rate law: rate = k[O3][ClO], we need to sum the powers of the reactant concentrations appearing in the rate law.
In this case, we have one reactant, O3, with a power of 1, and another reactant, ClO, also with a power of 1. Adding these powers together, we get an overall reaction order of 1 + 1 = 2.
Therefore, the correct answer is c. 2.
3. The initial reaction rate can be calculated by dividing the change in moles (∆n) by the change in time (∆t):
Rate = ∆n / ∆t.
Given that 0.03 moles are produced in a 1.5-L vessel in 3 seconds, we have ∆n = 0.03 moles and ∆t = 3 seconds.
Plugging these values into the formula, we get:
Rate = 0.03 moles / 3 seconds = 0.01 moles per second.
To convert moles per second to molarity per second (M/s), we need to divide the rate by the volume of the vessel (in liters). In this case, the volume is 1.5 L.
Rate = 0.01 moles / 1.5 liters = 0.0067 M/s.
Rounded to two decimal places, the initial reaction rate is approximately 0.01 M/s.
Therefore, the correct answer is a. 0.007 M/s.