Question

1. a chemical reaction produces 0.0125 mol of oxygen gas in 3 minutes and 30 seconds.

a) how many millimoles of oxygen is this?
/1
b) convert the reaction time to seconds.
/2
c) how many millimoles of oxygen are produced per second from the reaction?
/1

Explanation:

Step1: Convert moles to millimoles (part a)

Use conversion factor: $1\ \text{mol} = 1000\ \text{mmol}$
$\text{Millimoles of } \text{O}_2 = 0.0125\ \text{mol} \times 1000\ \frac{\text{mmol}}{\text{mol}}$

Step2: Convert time to seconds (part b)

Convert minutes to seconds: $1\ \text{min}=60\ \text{s}$
$\text{Total time} = (3\ \text{min} \times 60\ \frac{\text{s}}{\text{min}}) + 30\ \text{s}$

Step3: Calculate rate (part c)

Divide total millimoles by total time
$\text{Rate} = \frac{\text{Total millimoles of } \text{O}_2}{\text{Total time (s)}}$

Answer:

a) $12.5\ \text{millimoles}$
b) $210\ \text{seconds}$
c) $\frac{12.5}{210} \approx 0.0595\ \text{millimoles per second}$