Answer:
8.9 mg/l
Explanation: Temp doesnt matter so throw that out automatically then your equation is;
S1/P1=S2/P2
We are looking for S2 and that equation is;
S2=S1*P2/P1 and that is S2=22.25*1/2.5
A little bit of simple math and you get your answer: 8.9 mg/l
This is an incomplete question, here is a complete question.
The conversion of cyclopropane to propene occurs with a first-order rate constant of 2.42 × 10⁻² hr⁻¹. How long will it take for the concentration of cyclopropane to decrease from an initial concentration 0.080 mol/L to 0.053 mol/L?
Answer : The time taken will be, 17.0 hr
Explanation :
Expression for rate law for first order kinetics is given by:

where,
k = rate constant = 
t = time passed by the sample = ?
a = initial concentration of the reactant = 0.080 M
a - x = concentration left = 0.053 M
Now put all the given values in above equation, we get


Therefore, the time taken will be, 17.0 hr