Nitrogen dioxide, NO2, decomposes upon heating to form nitric oxide and oxygen according to the following equation: 2NO2(g)---->2NO(g) + O2(g)
At the beginning of an experiment, the concentration of nitrogen dioxide in a reaction vessel was 0.1103 mol/L. After 60.0 sec, the concentration decrease to 0.1076 mol/L. What is the average rate of decomposition of NO2 during this time interval, in mol/(L sec)?
To calculate the average rate of decomposition of NO2 during the given time interval, you need to use the formula:
Average Rate = (Change in concentration of NO2) / (Change in time)
First, calculate the change in concentration of NO2 by subtracting the initial concentration from the final concentration:
Change in concentration of NO2 = Final concentration - Initial concentration
= 0.1076 mol/L - 0.1103 mol/L
Next, calculate the change in time by subtracting the initial time from the final time:
Change in time = Final time - Initial time
= 60.0 sec - 0 sec
Now, substitute the values into the formula to find the average rate:
Average Rate = (Change in concentration of NO2) / (Change in time)
= (0.1076 mol/L - 0.1103 mol/L) / (60.0 sec - 0 sec)
Calculate the numerator first:
0.1076 mol/L - 0.1103 mol/L = -0.0027 mol/L
Then, calculate the denominator:
60.0 sec - 0 sec = 60.0 sec
Finally, substitute the values into the formula again to get the average rate:
Average Rate = (Change in concentration of NO2) / (Change in time)
= (-0.0027 mol/L) / (60.0 sec)
≈ -4.5 x 10^(-5) mol/(L sec)
Therefore, the average rate of decomposition of NO2 during the given time interval is approximately -4.5 x 10^(-5) mol/(L sec). Note that the negative sign indicates that the concentration of NO2 is decreasing with time.