The question is incomplete, here is the complete question:
At a certain temperature this reaction follows second-order kinetics with a rate constant of 14.1 M⁻¹s⁻¹

Suppose a vessel contains SO₃ at a concentration of 1.44 M. Calculate the concentration of SO₃ in the vessel 0.240 seconds later. You may assume no other reaction is important. Round your answer to 2 significant digits.
Answer: The concentration of
in the vessel after 0.240 seconds is 0.24 M
Step-by-step explanation:
For the given chemical equation:

The integrated rate law equation for second order reaction follows:
![k=(1)/(t)\left ((1)/([A])-(1)/([A]_o)\right)](https://img.qammunity.org/2021/formulas/chemistry/college/a2lj3jeijlgwg6ljnsxcls8m69g41v1xla.png)
where,
k = rate constant =

t = time taken= 0.240 second
[A] = concentration of substance after time 't' = ?
= Initial concentration = 1.44 M
Putting values in above equation, we get:
![14.1=(1)/(0.240)\left ((1)/([A])-(1)/(1.44)\right)](https://img.qammunity.org/2021/formulas/chemistry/college/vmg4f7wu1ne3zeuhhgw6osj1cfctkcw3ax.png)
![[A]=0.245M](https://img.qammunity.org/2021/formulas/chemistry/college/kxebyj8ts5qet10tc6ktyuhpwxc5dd4f9g.png)
Hence, the concentration of
in the vessel after 0.240 seconds is 0.24 M