General Chemistry Online: Companion Notes: Compounds: Polyatomic ions: Quiz

3. Sodium acetate is used in chemical handwarmers and heating pads because it gives up a large amount of heat when it changes from a liquid to a solid. The formula for this compound is:

Na₂C₂O₄

NaAc₂

NaC₂H₃O₂

NaC₂H₄O

Na₂C₂H₃O₂

4. Dichromate ions are used in the tanning of leather. Dichromate ion is:

CrO₄^2-

HCrO₄^-

Cr₂O₃^2-

HCrO₃^-

Cr₂O₇^2-

5. The SCN^- ion forms a bright red complex with iron(II) ions. The SCN^- ion is called the:

sulfurocyanide ion

thiocyanide ion

cyanate ion

thiocyanate ion

cyanide ion

thiocyanite ion

6. Phosphate ion is a basic building block of minerals, bones, teeth, and DNA. The formula of the phosphate ion is:

PO₄^3-

HPO₄^-2

PhO₂^-2

PO₄^2-

PO₃^-

7. Sodium sulfate occurs in nature as the minerals mirabilite and thenardite. The formula of the sulfate ion is:

HSO₄^-

S₂O₃^-2

SO₄^-

SO₃^2-

SO₄^2-

8. Hard water contains high concentrations of calcium ions. The water is "softened" by treatment with carbonate ions, which precipitates the calcium as insoluble calcium carbonate. The formula of carbonate ion is:

CO₃^2-

HCO₃^-

CO₃^-

CO₂^-

CO₂^2-

9. Sodium peroxide can be used for oxygen generation in diving bells and submarines, since it reacts with carbon dioxide and produces oxygen gas. The peroxide ion has the formula:

O₂⁺

O₂^2-

O₂^-

O^2-

O₃^-

10. NaClO₃ has been used in herbicides and in explosives. The name of this compound is:

sodium chloride

sodium perchlorate

sodium chlorite

sodium chloride trioxide

sodium chlorate

General Chemistry Online! Quiz