Answer
The concentration of that $HCl$ solution is equal to $1.00 \space M$.
Work Step by Step
1. Determine the molar mass of this compound ($HCl$), and setup the conversion factors:
Molar mass :
$H: 1.008g $
$Cl: 35.45g$
1.008g + 35.45g = 36.46g
$ \frac{1 \space mole \space (HCl)}{ 36.46 \space g \space (HCl)}$ and $ \frac{ 36.46 \space g \space (HCl)}{1 \space mole \space (HCl)}$
2. Calculate the number of moles $(HCl)$
$ 73.0 \space g \times \frac{1 \space mole}{ 36.46 \space g} = 2.00 \space moles$
3. Find the concentration in mol/L (Molarity) $(HCl)$:
$C(M) = \frac{n(moles)}{volume(L)}$
$ C(M) = \frac{ 2.00 \space moles}{ 2.00 \space L} $
$C(M) = 1.00 \space M$
