0.55g of hydrogen chloride (HCl) is dissolved in water to make 3.0L of solution. What is the pH of the resulting hydrochloric acid solution?
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First convert 0.55g of HCl into moles of HCl: 0.55/(1.01+35.4)=0.015mol.
Looking at the disassociation equation for HCl we can see that the ratio is 1:1:1
HCl -> H+ + Cl-
Therefore there is 0.015mol of H+ ions in the solution.
Next you need to find the concentration of the H+ ions or the molarity:
Molarity=moles/volume
=0.015/3
=0.005 M
The equation for pH is pH=-log[H+]
We know the concentration of H+ (0.005) so pH=-log(0.005)
=2.3
So the pH of the solution is 2.3
Looking at the disassociation equation for HCl we can see that the ratio is 1:1:1
HCl -> H+ + Cl-
Therefore there is 0.015mol of H+ ions in the solution.
Next you need to find the concentration of the H+ ions or the molarity:
Molarity=moles/volume
=0.015/3
=0.005 M
The equation for pH is pH=-log[H+]
We know the concentration of H+ (0.005) so pH=-log(0.005)
=2.3
So the pH of the solution is 2.3