Answer:
[tex]molarity =6.9\times 10^{-3}\ M\\[/tex]
Explanation:
We know that , the reaction of HCl and NaOH is given as follows
[tex]NaOH+HCl=NaCl +H_2O[/tex]
Given that
Pressure = 111 mm Hg
[tex]P=111\times 13.6\times 10^{-3}\times 9.81\times 1000=14.809\ kPa[/tex]
Temperature = 20°C
T=20+273=293 K
Volume= 221 m L
V=0.221 L
Number of moles of HCl is given as follows
[tex]n=\dfrac{P\times V}{R\times T}\\n=\dfrac{0.148\times 0.221}{0.821\times 293}=1.3\times 10^{-4}\ moles[/tex]
From the above reaction we can say that
Number of moles of HCl=Number of moles of NaOH
Volume of NaoH is given as follows
V=18.7 = 0.0187 L
Therefore molarity
[tex]molarity =\dfrac{n}{V_{NaOH}}\\molarity =\dfrac{1.3\times 10^{-4}}{0.0187}=6.9\times 10^{-3}\ M\\molarity =6.9\times 10^{-3}\ M\\[/tex]