Explanation:
The given data is:
The half-life of gentamicin is 1.5 hrs.
The reaction follows first-order kinetics.
The initial concentration of the reactants is 8.4 x 10-5 M.
The concentration of reactant after 8 hrs can be calculated as shown below:
The formula of the half-life of the first-order reaction is:

Where k = rate constant
t1/2=half-life
So, the rate constant k value is:

The expression for the rate constant is :

Substitute the given values and the k value in this formula to get the concentration of the reactant after time 8 hrs is shown below:

Answer: The concentration of reactant remains after 8 hours is 2.09x10^-6M.
Answer:
[O2(g)][SO2(g)]^2/[SO3(g)]^2
A gas can move around freely while a solid is hard and can’t move around freely
I think the correct answer would be because copper has a lower activity than hydrogen and cannot replace the bonds in it. Substances that are not oxidizing do not react with copper since the redox potentials are very low. Hope this answers the question.
Answer:
NOCl structure has geometry of trigonal planar and N has sp2 hybridisation. N is the central atom because it is less electronegative than O atom and Cl cannot be the central atom because it only forms a single bond. So, the central atom of NOCl is N and its hybridisation