Consider the reaction of peroxydisulfate ion (S2O82-) with iodide ion (I -) in aqueous solution.
S2O82-(aq) + 3 I -(aq) �¨ 2 SO42-(aq) + I3-(aq)
At a particular temperature, the rate of disappearance of S2O82- varies with reactant concentrations in the following manner.
Experiment [S2O82- ] (M) [I - ] (M) (M/s)
1 0.018 0.036 2.6 10-6
2 0.027 0.036 3.9 10-6
3 0.036 0.054 7.8 10-6
4 0.050 0.072 1.4 10-5
I got the rate constant to be .004 by the rate = k[S2O82-] . [I-]
but i have no idea how to get What is the rate of disappearance of I - when [S2O82- ] = 0.022 M and [I - ] = 0.042 M?
please help me and explain if possible
The rate of disappearance of I- when [S2O82-] = 0.022 M and [I-] = 0.042 M can be calculated using the rate constant you found. The rate of disappearance of I- is equal to the rate constant multiplied by the concentrations of S2O82- and I-:
Rate = k[S2O82-] . [I-]
Rate = 0.004 (0.022 M)(0.042 M)
Rate = 3.168 x 10-5 M/s
To find the rate of disappearance of I- when [S2O82-] = 0.022 M and [I-] = 0.042 M, we can use the rate law equation and the rate constant you have already calculated.
The rate law for this reaction is given as:
rate = k[S2O82-][I-]
Since you have already determined the rate constant (k = 0.004), you can substitute the given concentrations into the rate law equation:
[S2O82-] = 0.022 M
[I-] = 0.042 M
k = 0.004
rate = k[S2O82-][I-]
rate = 0.004 * (0.022 M) * (0.042 M)
Now, use a calculator to evaluate the expression:
rate = 0.004 * 0.022 * 0.042
The calculation gives:
rate = 3.024 x 10^-6 M/s
Therefore, the rate of disappearance of I- when [S2O82-] = 0.022 M and [I-] = 0.042 M is approximately 3.024 x 10^-6 M/s.
To determine the rate of disappearance of I- when [S2O82-] = 0.022 M and [I-] = 0.042 M, we can use the rate constant and the rate equation you have already mentioned.
Given:
[S2O82-] = 0.022 M
[I-] = 0.042 M
Rate constant (k) = 0.004 M/s (derived from the given data)
The rate equation for the reaction is:
Rate = k[S2O82-][I-]
Substituting the given values, we have:
Rate = (0.004 M/s)(0.022 M)(0.042 M)
Calculating the rate:
Rate = 0.000036168 M/s
Therefore, the rate of disappearance of I- when [S2O82-] = 0.022 M and [I-] = 0.042 M is approximately 3.62 x 10^-5 M/s.