Calculate the volume of a 30 % ($\rho_S=$ 1.1492 $\frac{g}{mL}$) solution $S$ of chlorhydric acid
that must be diluted in a volumetric flask $j$ of 1000 $mL$ in order to obtain a solution with $pH$ = 0.27
$HCl$: strong acid
Final solution:
$c$ $=$ $10^{-pH}$ =
$10^{-0.27}$ =
0.13 $\frac{mol}{L}$
$n_{HCl}$ =
$c_{HCl}\cdot V_{j}$ =
0.13$\cdot$1 =
0.13$\;mol$
The initial concentrated solution had the same number of moles:
Initial solution $S$:
$m_{HCl}$ =
$n_{HCl}\cdot M_{HCl}$ =
0.13$\cdot$36.47 =
4.741$\;g$
$m_S$ =
$\frac{m_{HCl}\cdot 100}{\%_S}$ =
$\frac{4.741\cdot 100}{30}$ =
15.803$\;g$
$V_S$ =
$\frac{m_S}{\rho_S}$ =
$\frac{4.741}{1.1492}$ =
4.125$\;mL$
