Polyatomic Ions Quiz
Questions: 16 · 10 minutes
1. A sample of ammonium chloride contains NH4Cl. Which part of the compound is the polyatomic ion?
Cl−, the monatomic chloride ion
NH4+, the ammonium ion
NH3, a neutral ammonia molecule
H+, the hydrogen ion
2. A formula unit contains two phosphate ions. If each phosphate ion is PO4³−, what combined charge do the two ions contribute?
2−, because there are two phosphate ions
3−, because the charge is counted only once
6+, because two ions reverse the sign
6−, because two 3− charges add together
3. Copper(II) is Cu2+ and acetate is C2H3O2−. Which formula represents neutral copper(II) acetate?
Cu(C2H3O2)2 — one copper ion with two acetate ions
Cu2(C2H3O2) — two copper ions with one acetate ion
CuC2H3O2 — a one-to-one ion ratio
Cu2(C2H3O2)3 — two copper ions with three acetate ions
4. In Fe2(SO4)3, each sulfate ion has a 2− charge. What charge must each iron ion have for the compound to be neutral?
A 2+ charge, producing four positive charges in total
A 3+ charge, producing six positive charges in total
A 1+ charge, producing two positive charges in total
A 6+ charge, producing twelve positive charges in total
5. What is the charge of the sulfate ion, SO4?
A positive charge of two
A positive charge of one
A negative charge of one
A negative charge of two
6. A student is given the formula NH4Cl. Which name correctly identifies the compound?
Nitrogen chloride
Ammonium chlorate
Ammonium chloride
Ammonium hypochlorite
7. The chlorine oxyanion with three oxygen atoms and a 1− charge is called chlorate. Which formula matches that description?
ClO−, containing one oxygen atom
ClO2−, containing two oxygen atoms
ClO3−, containing three oxygen atoms
ClO4−, containing four oxygen atoms
8. Calcium forms Ca2+ ions, while nitrate is NO3−. What is the neutral formula for calcium nitrate?
Ca2(NO3)3 — two calcium ions for three nitrates
Ca2NO3 — two calcium ions for one nitrate
CaNO3 — one calcium ion for one nitrate
Ca(NO3)2 — one calcium ion for two nitrates
9. Sodium is Na+ and phosphate is PO4³−. Which formula correctly balances their charges?
Na3PO4 — three sodium ions for one phosphate
Na2PO4 — two sodium ions for one phosphate
NaPO4 — one sodium ion for one phosphate
Na3(PO4)2 — three sodium ions for two phosphates
10. An antacid label lists an ion as CO3²−. Which identification is accurate?
Carbonate, an ion with a 2− charge
Hydrogen carbonate, an ion with a 1− charge
Sulfite, an ion containing sulfur
Phosphate, an ion with a 3− charge
11. Nitrate and nitrite have the same charge, but nitrite has one fewer oxygen atom. Which option identifies nitrite?
NO3−, with three oxygen atoms
NO2−, with two oxygen atoms
N2O3²−, with two nitrogen atoms
NO2²−, with a 2− charge
12. A magnesium ion is Mg2+ and a hydroxide ion is OH−. What is the formula for neutral magnesium hydroxide?
MgOH — one magnesium ion and one hydroxide
Mg2OH — two magnesium ions and one hydroxide
Mg(OH)2 — one magnesium ion and two hydroxides
Mg2(OH)2 — two magnesium ions and two hydroxides
13. Potassium permanganate has the neutral formula KMnO4. Because potassium is K+, how should the polyatomic part be identified?
MnO4−, the permanganate ion
MnO4²−, the manganate ion
CrO4²−, the chromate ion
Cr2O7²−, the dichromate ion
14. Which option correctly identifies hydrogen carbonate, also called bicarbonate?
CO3²−, the carbonate ion
H2CO3, neutral carbonic acid
HSO4−, the hydrogen sulfate ion
HCO3−, the hydrogen carbonate ion
15. Aluminum is Al3+ and sulfate is SO4²−. Which formula has an overall charge of zero?
AlSO4 — a one-to-one ion ratio
Al3(SO4)2 — three aluminum ions and two sulfates
Al2(SO4)3 — two aluminum ions and three sulfates
Al(SO4)3 — one aluminum ion and three sulfates
16. Which option correctly identifies the formula and charge of the nitrate ion?
NO2−, the nitrite ion
NO3−, the nitrate ion
CO3²−, the carbonate ion
SO3²−, the sulfite ion