Answer : The concentration of SO₂Cl₂ after 720 min will be, [tex]3.81\times 10^{-4}M[/tex]
Explanation :
Expression for rate law for first order kinetics is given by:
[tex]t=\frac{2.303}{k}\log\frac{a}{a-x}[/tex]
where,
k = rate constant = [tex]2.80\times 10^{-3}\text{ min}^{-1}[/tex]
t = time passed by the sample = 720 min
a = initial amount of the reactant = [tex]2.86\times 10^{-3}M[/tex]
a - x = amount left after decay process = ?
Now put all the given values in above equation, we get
[tex]720=\frac{2.303}{2.80\times 10^{-3}}\log\frac{2.86\times 10^{-3}}{a-x}[/tex]
[tex]a-x=3.81\times 10^{-4}M[/tex]
Therefore, the concentration of SO₂Cl₂ after 720 min will be, [tex]3.81\times 10^{-4}M[/tex]