C = n/X = (X.XXXXX XXXX)/(20.50 XX) = 0.0765 mol/L
XXX molarity XX XXX HCl XXXXXXXX is X.077 M.
X. The addition of XXX XXXXX XXXX XXX interfere XXXXX XXX XXXXXX XX XXXXX that XXX added XX XXXXX. XXX concentration of the XXXXXXXX sample "XX" can be calculated as XXXXX, XXX then XXX XXXXXXXX XXXXXXXX can be applied to find the original molarity "XX" XX the HCl XXXXXX:
XX = XXXX/XX = C2(40.XXXX/XX.XX XX)