Question

A reaction generates hydrogen gas (H) as a product. The re-

actants are mixed and sealed in a 250.-mL vessel. After

20.0 minutes, 3.91 X 10-2 mol H, has been generated.

Calculate the average rate of the reaction.

Answer 1

Answer: The average rate of the reaction is
`7.82* 10^(-3)M/min`

Step-by-step explanation:

To calculate the molarity of hydrogen gas generated, we use the equation:

`\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}`

Moles of hydrogen gas =
`3.91* 10^(-2)mol`

Volume of solution = 250 mL = 0.250 L (Conversion factor: 1 L = 1000 mL)

Putting values in above equation, we get:

`\text{Molarity of }H_2=(3.91* 10^(-2)mol)/(0.250L)=0.1564M`

Average rate of the reaction is defined as the ratio of concentration of hydrogen generated to the time taken.

To calculate the average rate of the reaction, we use the equation:

`\text{Average rate of the reaction}=\frac{\text{Concentration of hydrogen generated}}{\text{Time taken}}`

We are given:

Concentration of hydrogen generated = 0.1564 M

Time taken = 20.0 minutes

Putting values in above equation, we get:

`\text{Average rate of the reaction}=(0.1564M)/(20.0min)\\\\\text{Average rate of the reaction}=7.82* 10^(-3)M/min`

Hence, the average rate of the reaction is
`7.82* 10^(-3)M/min`