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.
2.B. Describe the difference between a reaction that occurs spontaneously and one that does not. Spontaneous chemical reactions release energy and use that energy to power itself; non-spontaneous chemical reactions need to absorb energy, which they can't absorb their own energy that they don't even have.
Answer:
See below
Explanation:
A chemist preforms the following: Neutralizing nitric acid (HNO3) with soda ash (Na2CO3). This reaction will then create sodium nitrate and carbonic acid, which will then decompose into water (H20)
The question is incomplete as it does not have the options which are:
A) anaphase
B) prophase
C) telophase
D) metaphase
E) interphase
Answer:
The correct answer will be option-D
Explanation:
Colchicine is a drug obtained from the <em>Colchicum autumnale</em> which is a poisonous European flowering plant. The drug is used to treat joint swelling and gout.
Colchicine shows its effect during the cell division cycle especially during the division of nuclear content. When the cell is in metaphase and is preparing for the anaphase, the colchicine inhibits the polymerisation of the microtubules. The inhibition of microtubules inhibits the assembly of the mitotic spindle as a result of this the DNA do not move into new daughter cells.
Thus, option-D is the correct answer.