an unknown salt is either NaCN,NaC2H3O2, NaF, NaCl, or NaOCl. when 0.100 molar of the salt is dissolved in 1.00 L of solution, the ph of the solution is 8.07. what is the identity of the salt?
where do I start? How do I solve it, cuz im not gettign right answer.
All of these hydrolyze (actually NaCl does not) like this.
..........A^- + HOH ==> HA + OH^-
I.......0.1..............0....0
C........-x..............x....x
E......0.1-x.............x....x
Kb for base = (Kw/Ka for HA) = (HA)(OH^-)/(A^-)
Substitute Kw, you have pH, I would convert that to pOH then to OH, substitute for OH and HA (they are the same), and solve for Ka. Then compare the Ka for HCN, HC2H3O2, HF, etc etc until you find the one with the right Ka value. That will tell you the salt you have. As you already know, it isn't NaCl because NaCl is pH = 7 in water solution.
poopoo
Well, chemistry can be a bit salty sometimes, but let's see if we can figure this out together! To determine the identity of the salt, we'll have to look at the pH of the solution and the anion of the salt.
The pH of 8.07 suggests that the solution is slightly basic. This means that the anion of the salt must be the source of hydroxide ions (OH-) in the solution.
Let's go through the options one by one and see which one fits the bill!
- NaCN: When NaCN dissolves in water, it forms Na+ and CN-. CN- does not react with water to produce OH-, so it can't be the salt we're looking for.
- NaC2H3O2: When NaC2H3O2 dissolves in water, it forms Na+ and C2H3O2-. C2H3O2- can react with water to produce OH-, so it's a possibility!
- NaF: When NaF dissolves in water, it forms Na+ and F-. F- does not react with water to produce OH-, so it's not the right salt.
- NaCl: When NaCl dissolves in water, it forms Na+ and Cl-. Cl- does not react with water to produce OH-, so it's not the salt we're looking for.
- NaOCl: When NaOCl dissolves in water, it forms Na+ and OCl-. OCl- can react with water to produce OH-, so it's another possibility!
Now, we have two potential options: NaC2H3O2 and NaOCl. To determine the final answer, we need to consider which one is a stronger base and would produce more OH- ions. NaOCl is a stronger base than NaC2H3O2, so it's the most likely salt that would result in a pH of 8.07.
Therefore, the identity of the salt is NaOCl. Hopefully, we've "solved" the puzzle together!
To determine the identity of the unknown salt, we can analyze the pH of the solution. The pH can help us identify the anion in the salt and narrow down our options.
Let's break down the process step by step:
Step 1: Identify the anions:
The possible anions in the salt are CN-, C2H3O2-, F-, Cl-, and OCl-.
Step 2: Determine the pH range for each anion:
- CN-: The cyanide ion is a weak base, and its presence in solution would result in a basic pH.
- C2H3O2-: The acetate ion is a weak base, and its presence in solution would result in a basic pH.
- F-: The fluoride ion is the conjugate base of a weak acid, and its presence in solution could result in a slightly acidic or neutral pH.
- Cl-: The chloride ion is the conjugate base of a strong acid, and its presence in solution would result in a neutral pH.
- OCl-: The hypochlorite ion is the conjugate base of a weak acid, and its presence in solution could result in a slightly basic or neutral pH.
Step 3: Compare the pH range to the observed pH:
The observed pH of the solution is 8.07. This falls within the pH range of a slightly basic solution but would also be within the range for a neutral solution.
Based on this information, we can eliminate CN-, C2H3O2-, and OCl- as potential anions because they would result in a pH that is either more basic or more neutral than the observed pH.
This leaves us with F- and Cl- as possible anions. Both F- and Cl- could potentially result in a pH around 8, so we need more information to determine the exact identity of the salt.
It is important to note that the analysis can be further refined by considering the cation in the salt (sodium, Na+), but based on the given information, we cannot directly deduce the cation's identity.
To identify the unknown salt, we can look at the pH of the solution when it is dissolved in water. Based on the given information, we know that 0.100 molar of the salt is dissolved in 1.00 L of solution, and the resulting pH is 8.07.
To solve this problem, we need to understand the concept of acid-base reactions and the properties of salts in water. Salts can be classified as neutral, acidic, or basic, depending on how they interact with water.
First, let's look at each salt option and determine their potential effects on the pH of the solution:
1. NaCN (sodium cyanide): This salt is derived from a strong base (NaOH) and a weak acid (HCN). It is considered a basic salt that can hydrolyze in water, producing hydroxide ions (OH-) and increasing the pH of the solution.
2. NaC2H3O2 (sodium acetate): This salt is derived from a strong base (NaOH) and a weak acid (CH3COOH). Like NaCN, it is considered a basic salt that can hydrolyze and increase the pH of the solution.
3. NaF (sodium fluoride): This salt is derived from a strong base (NaOH) and a weak acid (HF). Unlike NaCN and NaC2H3O2, NaF is considered a neutral salt because it does not significantly hydrolyze in water.
4. NaCl (sodium chloride): This salt is derived from a strong acid (HCl) and a strong base (NaOH). It is considered a neutral salt because it does not significantly affect the pH of the solution.
5. NaOCl (sodium hypochlorite): This salt is derived from a strong base (NaOH) and a weak acid (HClO). It is considered a basic salt that can hydrolyze, producing hydroxide ions (OH-) and increasing the pH of the solution.
Now, let's analyze the given pH of 8.07. An 8.07 pH indicates a slightly basic solution since it is above the neutral pH of 7. So, the solution's pH is likely affected by either NaCN, NaC2H3O2, or NaOCl.
To determine the identity of the salt, we need to compare the acid-base strength of the salts. NaCN and NaOCl are both basic salts, but NaCN comes from a weak acid, while NaOCl comes from a strong acid. Therefore, NaCN is more likely to increase the pH to a greater extent than NaOCl. However, we can also consider the concentration of the salt to make a final determination.
If the concentration of NaCN or NaOCl is significantly higher than NaC2H3O2, it could be responsible for the pH of 8.07. However, if the concentration of NaC2H3O2 is higher, it could also contribute to the pH of the solution. So, you should check the concentrations of the salts to make a more accurate determination.
In summary, based on the given pH of 8.07, the unknown salt is likely either NaCN, NaC2H3O2, or NaOCl. To determine the exact identity, you need to compare the concentrations of the salts in the solution.