A theory is a proposed explanation for an observation
Try googleing it that is how i got some of mine
The concentration of the HCl solution is 0.047 M.
Explanation:
Data given about acid and base:
volume of acid Vacid = 46.9 ml
molarity of acid =?
volume of the base (NaOH) = 16.4 ml
molarity of the base = 0.135 M
To know the concentration of the acid in this reaction, the formula used in titration is used. It is
Macid X Vacid = Mbase X Vbase
the formula is rewritten as:
Macid = 
putting the values in the equation:
Macid = 
= 0.047 M
the concentration of the acid i.e HCl in the solution is of 0.047 M.
Equilibrium occurs when the rate of the forward reaction is the same as the rate of the reverse reaction. This doesn't necessarily mean the concentrations or pressure are the same on both sides of the equation, only the rates are the same