125 mL of a stock HCl solution was diluted to make 300 mL of a 0.750 mol/L HCl solution. What was the concentration of the original stock solution?

c= 1.8 mol/l

Explanation: amount of substance remains same.

Amount of substance n = c1·V1 = c2·V2 and c1= c2·V2/ V1

Original concentration c1= 300 ml·0.750 mol/l / 125 ml

if the concentration of products is decreased, the equilibrium will shift toward the products). add an inert gas (one that is not involved in the reaction) to the constant-volume reaction mixture: this will increase the total pressure of the system, but will have no effect on the equilibrium condition.

explanation:

i belive it is water