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:
B
Explanation:
the gravitational force is a big play.
If one starts with 0.020 g of Mg, 0.0008 moles of H2 would be made if the reaction is complete.
Going by the balanced equation of reaction in the image, 1 mole of Mg will produce 1 mole of H2 in a complete reaction.
If 0.020 g of Mg is started with:
mole of Mg = mass/molar mass
= 0.020/24.3
= 0.0008 moles
Since the mole of Mg to H2 is 1:1, thus, 0.0008 moles of H2 will also be made from the reaction.
More on stoichiometry can be found here: brainly.com/question/9743981
Answer:
It's true.
Explanation:
In sub-energy level : number of orbitals

In my opinion, the best answer among the choices listed above is the first option. The major reason for chemical bonding is <span>for atoms to gain the stability of the octet. In general, chemical reactions happen in order for substances achieve stability or appropriately achieve equilibrium.</span>