Im really confused....Im being asked to find the highest pH of HI, KOH and HNO3 all with a concentration of 0.10M. I understand HOW to find it: ph=-log[concentration of H]....but wouldn't that technically mean the pH of HI and HNO3 are the same?!
Absolutely yes. HI is a strong acid, ionizing 100%, the same for HNO3, and KOH is a strong base and it ionizes 100%. Furthermore, the pOH of KOH will be the same as the pH of HNO3/HI.
so then how do I know which one has the highest ph?
oh wait, duh, nevermind. XD i got it
I can understand why you might find this confusing. The pH scale is a measure of the concentration of hydrogen ions (H+) in a solution, and it ranges from 0 to 14. However, it's important to remember that the pH of a solution depends on the concentration of the hydronium ions (H3O+), which are formed when the acidic hydrogen atom (H+) in a compound dissociates in water.
To find the highest pH among HI, KOH, and HNO3, we need to compare the strength of these compounds as acids or bases. HI is a strong acid, KOH is a strong base, and HNO3 is also a strong acid. To determine the pH, we only need to consider the acidic hydrogen in each compound.
HI and HNO3 both have a concentration of 0.10M, but they differ in their acidic strengths. Since HI is a strong acid, it ionizes completely in water, releasing a high concentration of H+ ions. On the other hand, HNO3 is also a strong acid but ionizes slightly less completely than HI. Therefore, the concentration of H3O+ ions is lower in HNO3 compared to HI, resulting in a higher pH for HI.
KOH, on the other hand, is a strong base. When it dissolves in water, it releases OH- ions, and the pH scale measures the concentration of H3O+ ions, not OH- ions. Therefore, a strong base like KOH does not have a pH value. Instead, it has a pOH value, which is the negative logarithm of the concentration of OH- ions.
So, in summary, the pH of HI will be lower than that of HNO3 since HI is a stronger acid. KOH, being a strong base, does not have a pH value.