Answer: D.
Explanation: A chemical reaction is said to be in a state of equilibrium when the rate of the forward reaction equals the rate of the backward reaction, thus, there is no net change in the concentration of reactants and products.
A bond between two atoms that SHARE electrons
The answer is A - cytosine and adenine
75mL=0.075L
Molarity=moles/Liters
Moles=0.075(3.50)
=0.2625
Since the number of moles never changes,
we know there are 0.2625moles (or 0.26) in the 12M HCl.
0.2625/12=0.021875L
(0.022L)