I really don't understand rate law. Could you explain that and help with this problem please?
Determine the average rate of change of B from t=0 s to t=202 s.
A-->2B
Time (s) Concentration of A (M)
0 0.74
101 0.45
202 0.16
The tabular data is for A. The question asks for B.
From 0 sec to 202 sec the change in A was 0.74 to 0.16 or -0.58.
Therefore, rate of change for A is -0.58 M/202 sec or 0.00287 M/s.
The problem asks for B. Therefore, rate of change for B is twice that.
-.00574
Sure! The rate law is an equation that relates the rate of a chemical reaction to the concentration of reactants. It helps us understand how the reaction proceeds over time.
In this case, the reaction is A --> 2B. The rate law for this reaction is typically determined experimentally. However, based on the stoichiometry of the reaction, we can see that the rate of disappearance of A is twice the rate of appearance of B.
To determine the average rate of change of B from t=0 s to t=202 s, we need to find the change in concentration of B and divide it by the change in time.
Initially, at t=0 s, the concentration of B is 0 M because no reaction has occurred yet. At t=202 s, we cannot directly determine the concentration of B because we only have information about the concentration of A at those times.
However, we can use the stoichiometry of the reaction to find the concentration of B at t=202 s indirectly. Since the reaction is 1 mole of A forming 2 moles of B, we can calculate the moles of A reacted using the concentration change of A from t=0 s to t=202 s.
Concentration change of A = Initial concentration of A - Final concentration of A
= 0.74 M - 0.16 M
= 0.58 M
The number of moles of A reacted can be found by multiplying the concentration change of A by the volume of the reaction (which is usually given in liters). However, since the volume is not provided, we cannot directly calculate the moles of A reacted.
Therefore, we cannot directly determine the concentration of B at t=202 s using the given information. Without this information, we cannot accurately calculate the average rate of change of B from t=0 s to t=202 s.