5. Which of the following solutions has the highest pH? *
1.0 M Li2SO4
1.0 M CuF2
1.0 M NH4Br
1.0 M K2CO3
Thank you!
Well, if you're looking for the solution with the highest pH, I must say we're venturing into high pH territory! But fear not, my friend, because the answer to this question is quite simple. The solution with the highest pH is none other than 1.0 M K2CO3! Why? Well, let's just say that potassium carbonate (K2CO3) is quite the alkaline character. It loves to release hydroxide ions (OH-) into solution, which makes it quite basic and, consequently, gives it a high pH. So if you're in need of a high pH solution, K2CO3 is your go-to buddy! Keep that alkalinity flowing, my friend!
To determine which solution has the highest pH, we need to compare the values of their pH. The pH scale ranges from 0 to 14, with lower values indicating acidic solutions and higher values indicating basic solutions.
Let's examine the cations and anions of each solution:
1.0 M Li2SO4:
- The cation is Li+, which is not typically considered as affecting pH.
- The anion is SO4^2-, which is derived from a strong acid (H2SO4). It does not significantly hydrolyze and does not affect the pH significantly.
1.0 M CuF2:
- The cation is Cu2+, which is not typically considered as affecting pH.
- The anion is F-, which is derived from a weak acid (usually HF). It partially hydrolyzes in water, making the solution slightly acidic.
1.0 M NH4Br:
- The cation is NH4+, which is derived from a weak base (NH3). It partially hydrolyzes in water, making the solution slightly acidic.
- The anion is Br-, which is not typically considered as affecting pH.
1.0 M K2CO3:
- The cation is K+, which is not typically considered as affecting pH.
- The anion is CO3^2-, which is derived from a weak base (usually H2CO3). It significantly hydrolyzes in water, making the solution basic.
Therefore, out of the given solutions, the 1.0 M K2CO3 solution has the highest pH because it is basic.
To determine which of the given solutions has the highest pH, we need to look at the properties of each compound.
The pH scale measures the acidity or basicity of a solution. A solution with a pH value less than 7 is considered acidic, while a solution with a pH greater than 7 is considered basic.
Now, let's analyze each compound:
1. Li2SO4: This compound is a salt and does not undergo hydrolysis, which means it does not produce any acidic or basic ions when dissolved in water. Therefore, it does not affect the pH of the solution significantly.
2. CuF2: Copper(II) fluoride is also a salt. However, when it dissolves in water, it undergoes hydrolysis to a small extent, releasing some fluoride ions (F^-). Fluoride ions are weak bases and can slightly increase the pH of the solution.
3. NH4Br: Ammonium bromide is an example of a salt containing a weak acid (NH4^+) and a strong base (Br^-). When dissolved in water, the ammonium ion (NH4^+) can undergo hydrolysis to a small extent, releasing hydrogen ions (H+). Hydrogen ions make the solution acidic and decrease the pH.
4. K2CO3: Potassium carbonate is a salt containing a strong base (KOH) and a weak acid (CO3^2-). When dissolved in water, the carbonate ion (CO3^2-) can undergo hydrolysis and release hydroxide ions (OH-), which makes the solution basic and increases the pH.
Based on the above analysis, the solution with the highest pH is 1.0 M K2CO3 because it contains a strong base that produces hydroxide ions, increasing the pH of the solution.
I'll show a couple of these and you do the others.
Li2SO4:
SO4^2- + HOH ==> HSO4^- + OH^-
1.0...............................0................0
-x.................................x.................x
1-x.................................x..................x
Kb for SO4^2- = Kw/K2 for H2SO4 = (x)(x)/(1-x)
Solve for x = (OH^-) and convert to pH.
NH4Br:
NH4^+ + H2O ==> NH3 + H3O^+
1.0.............................0...........0
-x................................x...........x
1-x.................................x...........x
Ka for NH4^+ = (Kw/Kb for NH3) = (x)(x)/(1-x)
Solve for x = (H3O^+) and convert to pH.
Do the others the same way and compare pH within the set.