Question

here is a graph of the pressure of boron trifluoride (bf₃) in a reaction vessel during a certain chemical reaction. use this graph to answer the questions in the table below.
is bf₃ being created or destroyed by the chemical reaction? created destroyed neither created nor destroyed
if bf₃ is being created or destroyed, what is the rate at which it is being created or destroyed 1000 seconds after the reaction starts? round your answer to 2 significant digits. also be sure your answer has the correct unit symbol.
if bf₃ is being created or destroyed, what is the average rate at which it is being created or destroyed during the first 1000 seconds of the reaction? round your answer to 2 significant digits. also be sure your answer has the correct unit symbol.

Explanation:

Step1: Determine creation or destruction

As the pressure of $BF_3$ is decreasing over time, it is being destroyed.

Step2: Find the instantaneous rate at 1000 s

To find the instantaneous rate at 1000 s, we need to find the slope of the tangent line to the curve at $t = 1000$ s. This requires drawing a tangent line at that point on the graph and estimating the change in pressure ($\Delta P$) over a small change in time ($\Delta t$). Let's assume we estimate the slope by taking a small interval around $t = 1000$ s. If we estimate the pressure at $t=900$ s as approximately $8$ atm and at $t = 1100$ s as approximately $6$ atm. Then $\Delta P=6 - 8=- 2$ atm and $\Delta t=1100 - 900 = 200$ s. The instantaneous rate $r=\frac{\Delta P}{\Delta t}=\frac{-2\text{ atm}}{200\text{ s}}=-0.010\text{ atm/s}$ (rounded to 2 significant - digits).

Step3: Find the average rate in the first 1000 s

The initial pressure at $t = 0$ s is $P_0=25.986$ atm and the pressure at $t = 1000$ s is estimated as approximately $8$ atm. The average rate $r_{avg}=\frac{\Delta P}{\Delta t}=\frac{8 - 25.986}{1000}\text{ atm/s}\approx - 0.018\text{ atm/s}$ (rounded to 2 significant - digits).

Answer:

Is $BF_3$ being created or destroyed by the chemical reaction? Destroyed
If $BF_3$ is being created or destroyed, what is the rate at which it is being created or destroyed 1000 seconds after the reaction starts? $-0.010\text{ atm/s}$
If $BF_3$ is being created or destroyed, what is the average rate at which it is being created or destroyed during the first 1000 seconds of the reaction? $-0.018\text{ atm/s}$