For my homework I got this problem that my professor never went over in class how to do it and I don't know how to interpret it.
A chemist runs a second order reaction of A->B starting at 10mili moles/L concentration of A (and no B). After one hour the concentration of the product has reached 6mili moles/L. Plot the concentration of B over the time until it reaches 9mili moles.
Do I start with this formula:
1/[A7]=kt+(1/A0)
How would I solve this problem and how would I put it in excel?
If you could help me out, I would really appreciate it. My assignment is due tomorrow,and I really need help.
To solve this problem, you're on the right track with the formula you mentioned. The formula you provided is one way to express the second-order reaction kinetics, which can be written as:
1/[A] = kt + 1/[A0]
Where [A] represents the concentration of A at a given time, k is the rate constant, t is the time, and [A0] is the initial concentration of A.
To solve for the rate constant (k) in your specific scenario, we can rearrange the equation:
1/[A] - 1/[A0] = kt
Since the problem states that after one hour, the concentration of B has reached 6 millimoles/L, we can substitute the respective values into the equation. Using [A] = 6 millimoles/L, and [A0] = 10 millimoles/L, we get:
1/6 - 1/10 = k * 1
Simplifying the equation gives:
5/30 - 3/30 = k
2/30 = k
k = 1/15
Now that we know the rate constant (k), we can plot the concentration of B as a function of time until it reaches 9 millimoles/L.
To plot this in Excel, follow these steps:
1. Create two columns, one for time and another for the concentration of B.
2. In the time column, enter the desired time intervals at which you want to plot the concentration of B. For example, you can start with 0, 1, 2, 3, ..., until the concentration reaches 9 millimoles/L.
3. In the first cell of the concentration of B column (corresponding to t = 0), enter the initial concentration of B: 0 millimoles/L.
4. In the second cell of the concentration of B column (corresponding to t = 1), enter the formula: =1/(1/15 * A2 + 1/10).
Explanation: A2 represents the cell containing the time value, and the formula represents the rearranged formula we derived earlier.
5. Copy the formula in step 4 and paste it for the remaining cells in the concentration of B column.
6. Excel will automatically calculate the values of B based on the formula, giving you the concentration of B at different time intervals until it reaches 9 millimoles/L.
7. Plot a graph with time on the x-axis and the concentration of B on the y-axis using the data you obtained in step 6.
Remember to adjust the time intervals and the range of the graph to adequately represent the behavior of the reaction until the desired concentration of B is reached.
I hope this explanation helps you solve the problem and plot the graph in Excel. If you have any further questions, feel free to ask!