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What polyatomic ions have a 3- charge?Check all that apply

What polyatomic ions have a 3- charge?Check all that apply-example-1
User Azad Salahli
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2 Answers

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- Phosphate (PO4^3-) has a charge of 3-.

- Hydrogen phosphate (HPO4^2-) has a charge of 2-.

- Acetate (C2H3O2^-) is typically considered to have a charge of 1-.

- Sulfate (SO4^2-) has a charge of 2-.

- Hydroxide (OH^-) has a charge of 1-.

- Dichromate (Cr2O7^2-) has a charge of 2-.

1. **Phosphate (PO4^3-):**

- Phosphate consists of one phosphorus atom (P) and four oxygen atoms (O).

- The charge of oxygen ions (O) is typically 2-.

- So, the total charge contributed by the four oxygen ions is 4 × (-2) = -8.

- To find the charge on the phosphorus ion (P), we use the fact that the overall ion has a 3- charge.

- Let "x" be the charge on the phosphorus ion (P).

- The sum of the charges must equal -3 because the ion is PO4^3-.

- Equation: x + (-8) = -3

- Add 8 to both sides: x - 8 + 8 = -3 + 8

- x = 5

- So, the charge on the phosphorus ion (P) in phosphate (PO4^3-) is 5+.

2. **Hydrogen phosphate (HPO4^2-):**

- Hydrogen phosphate is derived from phosphate by adding a hydrogen ion (H+).

- We already determined that phosphate (PO4^3-) has a charge of 3-.

- When you add one hydrogen ion (H+) to it, it will reduce the overall charge by 1.

- So, the charge on hydrogen phosphate (HPO4^2-) is 3 - 1 = 2-.

3. **Acetate (C2H3O2^-):**

- Acetate consists of two carbon atoms (C), three hydrogen atoms (H), and two oxygen atoms (O).

- Carbon typically forms a 4- bond, and hydrogen is 1+.

- The two oxygen atoms typically have a combined charge of 2 × (-2) = -4.

- Let "x" be the charge on the acetate ion.

- Equation: 2(4-) + 3(1+) + 2x = ?

- 8- + 3+ + 2x = ?

- Sum of the charges = 8- + 3+ = 5-

- Equation: 5- + 2x = ?

- Subtract 5- from both sides: 5- - 5- + 2x = ? - 5-

- 2x = ?

- Dividing by 2: 2x/2 = ?/2

- x = ?/2

- So, the charge on the acetate ion (C2H3O2^-) is ?/2. This ion is typically considered as having a 1- charge.

4. **Sulfate (SO4^2-):**

- Sulfate consists of one sulfur atom (S) and four oxygen atoms (O).

- The charge of oxygen ions (O) is typically 2-.

- So, the total charge contributed by the four oxygen ions is 4 × (-2) = -8.

- To find the charge on the sulfur ion (S), we use the fact that the overall ion has a 2- charge.

- Let "x" be the charge on the sulfur ion (S).

- The sum of the charges must equal -2 because the ion is SO4^2-.

- Equation: x + (-8) = -2

- Add 8 to both sides: x - 8 + 8 = -2 + 8

- x = 6

- So, the charge on the sulfur ion (S) in sulfate (SO4^2-) is 6+.

5. **Hydroxide (OH^-):**

- Hydroxide consists of one oxygen atom (O) and one hydrogen atom (H).

- Oxygen typically has a 2- charge, and hydrogen is 1+.

- So, the charge on the hydroxide ion (OH^-) is 2- + 1+ = 1-.

6. **Dichromate (Cr2O7^2-):**

- Dichromate consists of two chromium atoms (Cr) and seven oxygen atoms (O).

- The charge of oxygen ions (O) is typically 2-.

- So, the total charge contributed by the seven oxygen ions is 7 × (-2) = -14.

- To find the charge on the chromium ion (Cr), we use the fact that the overall ion has a 2- charge.

- Let "x" be the charge on the chromium ion (Cr).

- The sum of the charges must equal -2 because the ion is Cr2O7^2-.

- Equation: 2x + (-14) = -2

- Add 14 to both sides: 2x - 14 + 14 = -2 + 14

- 2x = 12

- Dividing by 2: 2x/2 = 12/2

- x = 6

- So, the charge on the chromium ion (Cr) in dichromate (Cr2O7^2-) is 6

User Alejnavab
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Answer:

Phosphate ion only

Step-by-step explanation:

Here, we want to get the polyatomic ions with a charge of -3

What we have to do here is to write the polyatomic ions and their formula

We have this as follows:


\begin{gathered} \text{Phosphate ion - PO}^(3-)_4 \\ \text{Acetate ion - }C_2H_3O^-_2 \\ Sulfate-SO^(2-)_{4^{}} \\ Hydro* ide-OH^- \\ \\ \text{Dichromate - Cr}_2O^(2-)_7 \\ \text{Hydrogen phosphate - HPO}^(2-)_4 \end{gathered}

From the above, the polyatomic ions with a charge of -3 is the Phosphate ion only

User Rohit Salecha
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