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.
Given :
A 3.82L balloon filled with gas is warmed from 204.9K to 304.8 K.
To Find :
The volume of the gas after it is heated.
Solution :
Since, their is no information about pressure in the question statement let us assume that pressure is constant.
Now, we know by ideal gas equation at constant pressure :

Hence, this is the required solution.
The answer would be A) sand, it is not soluble in water
Answer: The blood circulatory system (cardiovascular system) delivers nutrients and oxygen to all cells in the body.
Explanation: