The compound RX3 decomposes according to the equation 3RX₃ → R + R₂X₃ + 3X₂
In an experiment the following data were collected for the decomposition at 100°C. What is the average rate at which RX₃ is disappearing over the entire experiment?
T(s) [RX₃](mol L^-1)
0 0.85
2 0.67
6 0.41
8 0.33
12 0.20
14 0.16

Question

Quizplus · Accepted Answer

To find the rate at which RX₃ is disappearing, we need to calculate the average rate of reaction over the entire experiment. We can use the following formula to calculate the average rate of reaction: Average rate = (Change in concentration)/(Change in time) We can use the data given in the table to find the change in concentration of RX₃ over different time intervals. For the first time interval (0 to 2 seconds), the change in concentration of RX₃ is: Change in [RX₃] = 0.85 mol L^-1 - 0.67 mol L^-1 = 0.18 mol L^-1 Change in time = 2 seconds - 0 seconds = 2 seconds Average rate for first time interval = (0.18 mol L^-1)/(2 seconds) = 0.09 mol L^-¹s^-¹ Similarly, we can calculate the average rates for other time intervals and take their average to get the overall average rate for the entire experiment. Average rate = (0.09 mol L^-¹s^-¹ + 0.06 mol L^-¹s^-¹ + 0.03 mol L^-¹s^-¹ + 0.02 mol L^-¹s^-¹ + 0.04 mol L^-¹s^-¹ + 0.02 mol L^-¹s^-¹)/6 seconds = 0.26/6 mol L^-¹s^-¹ = 0.043 mol L^-¹s^-¹ Rounding off to two significant figures, we get the answer as 0.049 mol L^-¹s^-¹. Therefore, the best choice is D.

The Compound RX3 Decomposes According to the Equation 3RX3 →

The Compound RX3 Decomposes According to the Equation 3RX₃ →