Question

what polyatomic ions have a 3 - charge?
check all that apply.

□ acetate
□ sulfate
□ hydrogen phosphate
□ dichromate
□ phosphate
□ hydroxide

Explanation:

1. Recall the charges of each polyatomic ion:

• Acetate ($\ce{C2H3O2^-}$) has a 1 - charge.
• Sulfate ($\ce{SO4^{2-}}$) has a 2 - charge.
• Hydrogen phosphate ($\ce{HPO4^{2-}}$) has a 2 - charge.
• Dichromate ($\ce{Cr2O7^{2-}}$) has a 2 - charge.
• Phosphate ($\ce{PO4^{3-}}$) has a 3 - charge.
• Hydroxide ($\ce{OH^-}$) has a 1 - charge.

1. From the above, only phosphate has a 3 - charge. Wait, wait, let's re - check hydrogen phosphate. Wait, hydrogen phosphate is $\ce{HPO4^{2-}}$, charge is 2 -. Phosphate is $\ce{PO4^{3-}}$, charge 3 -. Wait, is there any other? Wait, maybe I made a mistake. Wait, let's list the charges again:

• Acetate: $\ce{CH3COO^-}$ (1 -)
• Sulfate: $\ce{SO4^{2-}}$ (2 -)
• Hydrogen phosphate: $\ce{HPO4^{2-}}$ (2 -)
• Dichromate: $\ce{Cr2O7^{2-}}$ (2 -)
• Phosphate: $\ce{PO4^{3-}}$ (3 -)
• Hydroxide: $\ce{OH^-}$ (1 -)

Wait, but maybe the question has a typo or maybe I missed. Wait, another ion with 3 - charge is phosphate ($\ce{PO4^{3-}}$). Also, maybe phosphate and is there any other? Wait, the options given: among the options, only phosphate has a 3 - charge. Wait, no, wait, maybe the user made a mistake in the options? Wait, no, the options are acetate, sulfate, hydrogen phosphate, dichromate, phosphate, hydroxide. So the correct one is phosphate.

Answer:

phosphate (the checkbox next to "phosphate" should be checked)