Half life of first order reaction is 3 hrs. what percentage reaction is completed in 9hrs ?​

92.6%

Explanation:

Hello there!

In this case, according to the first-order kinetics, we can write:

Whereas we need to know the rate constant in order to compute the percentages, given the half-life:

In such a way, we can now compute the fraction in which the reaction has been completed after 3 hrs:

And the percent would be 92.6% after multiplying the fraction by 100 %.

Best regards!

oxygen, selenium, tellurium, and polonium.

they're all from the same group as sulfur (group 16).