HELP concentrations of ions

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In summary: M[HPO4^2-] = 7.0M[PO4^3-] = 7.0MI hope this helps! Please let me know if you have any other questions.
  • #1
yuuri14
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HELP! concentrations of ions

Homework Statement


Determine the concentration for the following ions:
H2PO4-
HPO4^2-
PO4^3- in the dissociated of 7.0M H3PO4 solution


Homework Equations


I know that the number given is a phosphoric acid and is a triprotic acid.
Concentration of atoms example are Na2CO3 (s) → 2 Na+(aq)+ CO32-(aq)
[Na+] = 2 × [Na2CO3] = 2 × 0.20 M = 0.40 M
[CO32-] = 1 × [Na2CO3] = 1 × 0.20 M = 0.20 M


The Attempt at a Solution


so is it H2PO4-(aq) + H2O(l) = H30(aq) + H2PO4^2-(aq)
[H2PO4-]= 1 x [H2PO4-] = 1 x 7.0 = 7M then do the same thing for the two instead of 1 do 2 and 3 respectively next.
 
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  • #2


Hello! It looks like you are trying to determine the concentration of ions in a solution of H3PO4. This is a great question and I would be happy to help you with it. First, let's review some basic principles of dissociation and concentration.

When a compound, such as H3PO4, dissociates in water, it breaks apart into its constituent ions. In the case of H3PO4, it will dissociate into H+ and H2PO4-. This means that for every mole of H3PO4 that dissociates, you will get one mole of H+ ions and one mole of H2PO4- ions.

Now, let's apply this to your question. You are given a 7.0M solution of H3PO4. This means that for every liter of solution, there are 7 moles of H3PO4. Since H3PO4 is a triprotic acid, it will dissociate in three stages, each with its own equilibrium constant. The first dissociation will produce H+ and H2PO4-, the second will produce H+ and HPO4^2-, and the third will produce H+ and PO4^3-.

To determine the concentration of each ion, we must first determine the moles of each ion produced in each stage of dissociation. For the first dissociation, we will get 7 moles of H+ and 7 moles of H2PO4-. This means that the concentration of H+ ions will be 7.0M, and the concentration of H2PO4- ions will also be 7.0M.

For the second dissociation, we must consider that the H2PO4- ions from the first dissociation will also dissociate, producing more H+ and HPO4^2- ions. Since the concentration of H2PO4- ions is 7.0M, we will get 7.0M of H+ ions and 7.0M of HPO4^2- ions. Similarly, for the third dissociation, we will get 7.0M of H+ ions and 7.0M of PO4^3- ions.

In summary, the concentrations of each ion in a 7.0M solution of H3PO4 will be:
[H+] = 7.0M
[H2PO4-] = 7.
 

1. What is the significance of "HELP concentrations of ions" in scientific research?

In scientific research, "HELP concentrations of ions" refers to the measurement of the concentration of ions in a solution. This is important because the concentration of ions can have a significant impact on the chemical and physical properties of a solution, and can also affect the behavior of biological systems.

2. How are "HELP concentrations of ions" typically measured?

The concentration of ions in a solution can be measured using various techniques, such as titration, spectroscopy, or ion-selective electrodes. These methods involve the use of specific chemical or physical properties of the ions to determine their concentration in the solution.

3. What factors can influence the "HELP concentrations of ions" in a solution?

The concentration of ions in a solution can be influenced by several factors, including the type and amount of solute present, temperature, pH, and the presence of other substances that can interact with the ions. Changes in these factors can lead to changes in the concentration of ions in the solution.

4. Why is it important to maintain precise "HELP concentrations of ions" in certain experiments?

In certain experiments, maintaining precise concentrations of ions is crucial for obtaining accurate and reliable results. This is because even small changes in ion concentration can significantly affect the outcome of the experiment. Therefore, precise control of ion concentrations is necessary to ensure the validity of the results.

5. How do "HELP concentrations of ions" impact biological systems?

The concentration of ions in biological systems, such as cells and tissues, plays a crucial role in various physiological processes, including nerve impulses, muscle contractions, and enzyme activity. Imbalances in ion concentrations can disrupt these processes and lead to various health issues. Therefore, understanding and maintaining appropriate concentrations of ions is important for maintaining the health and functioning of biological systems.

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