Question 1
The reaction that occurs in a Breathalyzer, a device used to determine the alcohol level in a person's bloodstream, is given below. If the rate of appearance of Cr
2(SO
4)
3 is 1.64 mol min
-1 at a particular moment, what is the rate of disappearance of C
2H
6O at that moment?
2K
2Cr
2O
7 + 8H
2SO
4 + 3C
2H
6O → 2Cr
2(SO
4)
3 + 2K
2SO
4 + 11H
2O
◦ 1.09 mol min
-1◦ 4.92 mol min
-1◦ 2.46 mol min
-1◦ 0.547 mol min
-1Question 2
For a particular first-order reaction, it takes 24 minutes for the concentration of the reactant to decrease to 25% of its initial value. What is the value for rate constant (in s
-1) for the reaction?
◦ 2.0 × 10
-4 s
-1◦ 5.8 × 10
-2 s
-1◦ 9.6 × 10
-4 s
-1◦ 1.2 × 10
-2 s
-1