Ionic Compound Naming Flashcards: Names, Formulas & Charge Balance
Practice ionic compound naming with 56 English flashcards on neutral formulas, Roman numerals, polyatomic-ion parentheses, and common errors.
About this deck
Practice ionic compound names and neutral formulas with 56 English flashcards. This focused deck is for high-school and introductory-college learners who know basic ions and want to apply charge balance consistently.
The cards practice names to formulas, selected formulas back to names, metal-charge inference, one polyatomic-group count, and short repairs of incorrect formulas or missing naming information. Ion charges and polyatomic-ion names are supplied where the target is applying a rule. This is compound-naming practice rather than a table of isolated ions; use the polyatomic ion flashcards for that prerequisite.
The sequence begins with neutrality, cation-first order, subscripts, and the smallest whole-number ratio of intact ions. Fixed-charge binary salts come next, followed by iron, copper, and tin Stock names. Polyatomic groups and ammonium then lead into mixed formula, naming, and error-repair prompts. Selected reverse directions and closely related variants are separated. Every card carries the ionic-naming tag; the review scheduler handles longer-term spacing.
Names follow the usual introductory convention: fixed-charge cations without Roman numerals, variable-charge monatomic metals with Stock Roman numerals, and familiar polyatomic-ion names. Aluminum and aluminium are accepted spelling variants; sodium hydrogen carbonate and sodium bicarbonate are both accepted. This convention does not exhaust all valid systematic names. Arbitrary name-to-example prompts and exhaustive reversals are omitted because they add ambiguity or repetition. Covalent naming, acids, hydrates, organic compounds, coordination complexes, peroxide and mercury(I) special cases, reactions, and solubility are outside this deck. No full-course or examination alignment is claimed.
The questions, explanations, order, and metadata were written independently with AI assistance. Naming and ion facts were checked against Purdue University’s ionic-naming rules and ion reference tables. No competitor cards, source exercise wording, examination questions, or source diagrams were copied. Reference works retain their own rights, and chemical facts are not claimed as proprietary. Original material, including the AI-generated decorative charge-symbol cover, is dedicated under CC0 1.0 to the extent applicable rights exist. This is independent study material without institutional endorsement.
Cards in this deck
Card 1
Question
In a neutral ionic formula unit, what must the total ionic charge be?
Answer
Zero. The positive and negative charges must cancel.
Card 2
Question
When naming a simple ionic compound, which ion is named first?
Answer
The cation, followed by the anion.
Card 3
Question
Write the formula for lithium fluoride using Li⁺ and F⁻.
Answer
LiF. One ion of each kind gives +1 − 1 = 0.
Card 4
Question
In CaCl₂, what does the subscript 2 count?
Answer
Two chloride ions for each calcium ion. It does not mean that each chloride ion has a charge of −2.
Card 5
Question
Name MgO using the usual fixed-charge ionic naming convention.
Answer
Magnesium oxide. The ions are Mg²⁺ and O²⁻.
Card 6
Question
What is the smallest neutral ratio of Al³⁺ ions to O²⁻ ions?
Answer
Two Al³⁺ ions to three O²⁻ ions: +6 and −6 cancel.
Card 7
Question
Write the formula for magnesium bromide using Mg²⁺ and Br⁻.
Answer
MgBr₂. Two bromide ions balance one magnesium ion.
Card 8
Question
Name Na₂S using the usual fixed-charge ionic naming convention.
Answer
Sodium sulfide. The sulfur anion is called sulfide.
Card 9
Question
Write the simplest formula for calcium oxide using Ca²⁺ and O²⁻.
Answer
CaO. Equal and opposite charges give a 1:1 ion ratio.
Card 10
Question
Write the formula for aluminum nitride using Al³⁺ and N³⁻.
Answer
AlN. One ion of each kind is neutral. Aluminium nitride is the same compound, with the British spelling.
Card 11
Question
Name Mg₃N₂ using the usual fixed-charge ionic naming convention.
Answer
Magnesium nitride. Three Mg²⁺ ions balance two N³⁻ ions.
Card 12
Question
Write the formula for lithium oxide using Li⁺ and O²⁻.
Answer
Li₂O. Two lithium ions balance one oxide ion.
Card 13
Question
Name CaF₂ using the usual fixed-charge ionic naming convention.
Answer
Calcium fluoride. This convention uses the ion names without a di- prefix for the two fluoride ions.
Card 14
Question
A student writes Mg₂O₂ for magnesium oxide, using Mg²⁺ and O²⁻. What is the simplest formula?
Answer
MgO. The 2:2 ion ratio is neutral but reduces to 1:1.
Card 15
Question
Name Al₂S₃ using the usual fixed-charge ionic naming convention.
Answer
Aluminum sulfide (also spelled aluminium sulfide). Two Al³⁺ ions balance three S²⁻ ions.
Card 16
Question
Write the formula for sodium phosphide using Na⁺ and P³⁻.
Answer
Na₃P. Three sodium ions balance one phosphide ion.
Card 17
Question
Name LiF using the usual fixed-charge ionic naming convention.
Answer
Lithium fluoride. Name the lithium cation first and the fluoride anion second.
Card 18
Question
Write the formula for magnesium oxide using Mg²⁺ and O²⁻.
Answer
MgO. The smallest neutral ratio is one magnesium ion to one oxide ion.
Card 19
Question
In the Stock name iron(III) chloride, what does III specify?
Answer
A +3 charge on each iron ion. For this monatomic ion, its charge equals its oxidation state; III is not an atom count.
Card 20
Question
Name FeCl₂ using Stock nomenclature. Chloride is Cl⁻.
Answer
Iron(II) chloride. Two chloride ions total −2, so the iron ion is Fe²⁺.
Card 21
Question
What is the charge on each copper ion in Cu₂O, taking oxide as O²⁻?
Answer
+1. The two copper ions together must supply +2, so each is Cu⁺.
Card 22
Question
Write the formula for tin(IV) oxide, using oxide O²⁻.
Answer
SnO₂. One Sn⁴⁺ ion balances two oxide ions; reduce a crossed 2:4 ratio to 1:2.
Card 23
Question
Name Fe₂O₃ using Stock nomenclature. Oxide is O²⁻.
Answer
Iron(III) oxide. Three oxide ions total −6; divided between two iron ions, that requires Fe³⁺.
Card 24
Question
Write the formula for copper(II) bromide, using bromide Br⁻.
Answer
CuBr₂. One Cu²⁺ ion needs two bromide ions.
Card 25
Question
Name SnCl₂ using Stock nomenclature. Chloride is Cl⁻.
Answer
Tin(II) chloride. Two Cl⁻ ions require one Sn²⁺ ion.
Card 26
Question
Write the formula for iron(II) chloride, using chloride Cl⁻.
Answer
FeCl₂. One Fe²⁺ ion balances two chloride ions.
Card 27
Question
Name CuO using Stock nomenclature. Oxide is O²⁻.
Answer
Copper(II) oxide. The 1:1 ratio requires Cu²⁺ to balance O²⁻.
Card 28
Question
Write the formula for iron(III) sulfide, using sulfide S²⁻.
Answer
Fe₂S₃. Two Fe³⁺ ions supply +6 and three sulfide ions supply −6.
Card 29
Question
Why is the name copper chloride insufficient to choose a single formula in introductory Stock nomenclature?
Answer
It omits the copper oxidation state. Copper(I) chloride is CuCl; copper(II) chloride is CuCl₂.
Card 30
Question
Name SnO₂ using Stock nomenclature. Oxide is O²⁻.
Answer
Tin(IV) oxide. Two oxide ions total −4, so the tin ion is Sn⁴⁺.
Card 31
Question
A student labels Fe₂O₃ as iron(II) oxide. Keeping the name iron(II) oxide, what formula should replace it?
Answer
FeO. Fe²⁺ and O²⁻ balance in a 1:1 ratio; Fe₂O₃ instead corresponds to iron(III) oxide.
Card 32
Question
Name CaCl₂ using the usual introductory fixed-charge convention.
Answer
Calcium chloride. Calcium is treated as Ca²⁺, so this convention omits the Roman numeral. An explicit oxidation-state name is not a different compound.
Card 33
Question
Write the formula for sodium nitrate using Na⁺ and NO₃⁻.
Answer
NaNO₃. One nitrate ion balances one sodium ion; keep the nitrate formula intact.
Card 34
Question
Name K₂CO₃. The polyatomic ion CO₃²⁻ is carbonate.
Answer
Potassium carbonate. Two K⁺ ions balance one carbonate ion.
Card 35
Question
When writing a conventional ionic formula, when do you put a polyatomic ion in parentheses?
Answer
When more than one of that whole ion is needed. Put the count outside the parentheses and leave the ion’s internal subscripts unchanged.
Card 36
Question
Write the formula for calcium hydroxide using Ca²⁺ and OH⁻.
Answer
Ca(OH)₂. Two whole hydroxide ions balance one calcium ion.
Card 37
Question
Name NH₄Cl. NH₄⁺ is ammonium.
Answer
Ammonium chloride. The cation is the whole NH₄⁺ ion, even though it contains no metal.
Card 38
Question
Write the formula for aluminum sulfate using Al³⁺ and SO₄²⁻.
Answer
Al₂(SO₄)₃. Two aluminum ions supply +6 and three intact sulfate ions supply −6.
Card 39
Question
Name Mg(NO₃)₂. NO₃⁻ is nitrate.
Answer
Magnesium nitrate. One Mg²⁺ ion is balanced by two nitrate ions.
Card 40
Question
Write the formula for ammonium phosphate using NH₄⁺ and PO₄³⁻.
Answer
(NH₄)₃PO₄. Three ammonium ions balance one phosphate ion; only ammonium needs parentheses.
Card 41
Question
How many whole hydroxide ions are represented in one formula unit of Ba(OH)₂?
Answer
Two hydroxide ions. The outer subscript multiplies the entire OH group, giving two O atoms and two H atoms.
Card 42
Question
Name Fe₂(SO₄)₃ using Stock nomenclature. SO₄²⁻ is sulfate.
Answer
Iron(III) sulfate. Three sulfate ions total −6, so each of the two iron ions has charge +3.
Card 43
Question
Write the formula for calcium nitrate using Ca²⁺ and NO₃⁻.
Answer
Ca(NO₃)₂. Two intact nitrate ions supply −2 to balance calcium’s +2.
Card 44
Question
Name (NH₄)₂SO₄. NH₄⁺ is ammonium and SO₄²⁻ is sulfate.
Answer
Ammonium sulfate. Two ammonium ions balance one sulfate ion.
Card 45
Question
Write the formula for magnesium phosphate using Mg²⁺ and PO₄³⁻.
Answer
Mg₃(PO₄)₂. Three magnesium ions and two phosphate ions give +6 and −6.
Card 46
Question
Name NaHCO₃. HCO₃⁻ is hydrogen carbonate, also called bicarbonate.
Answer
Sodium hydrogen carbonate, also called sodium bicarbonate. HCO₃⁻ is one intact anion.
Card 47
Question
Repair AlOH₃ as the formula for aluminum hydroxide, using Al³⁺ and OH⁻.
Answer
Al(OH)₃. Three whole hydroxide ions are needed. AlOH₃ fails to multiply the oxygen count along with the hydrogen count.
Card 48
Question
Write the formula for ammonium sulfite using NH₄⁺ and SO₃²⁻.
Answer
(NH₄)₂SO₃. Two ammonium ions balance one sulfite ion; sulfite retains its three oxygen atoms.
Card 49
Question
Name Cu(NO₃)₂ using Stock nomenclature. NO₃⁻ is nitrate.
Answer
Copper(II) nitrate. Two nitrate ions total −2, requiring Cu²⁺.
Card 50
Question
Write the formula for iron(III) sulfate, using sulfate SO₄²⁻.
Answer
Fe₂(SO₄)₃. Two Fe³⁺ ions balance three sulfate ions.
Card 51
Question
Repair K(CO₃)₂ as the formula for potassium carbonate, using K⁺ and CO₃²⁻.
Answer
K₂CO₃. Two potassium ions balance one carbonate ion. A single carbonate group needs no parentheses.
Card 52
Question
Can Mg(NO₃)₂ be simplified to MgNO₃ by removing the outer subscript? Use Mg²⁺ and NO₃⁻.
Answer
No. The ion ratio is already 1:2. Removing the outer 2 would leave total charge +1 instead of zero.
Card 53
Question
Name Ca(OH)₂. OH⁻ is hydroxide.
Answer
Calcium hydroxide. The two hydroxide ions balance one Ca²⁺ ion; the ion name stays hydroxide.
Card 54
Question
What is the charge on each copper ion in Cu₃(PO₄)₂, taking phosphate as PO₄³⁻?
Answer
+2. Two phosphate ions total −6, shared equally among three copper ions as +2 each.
Card 55
Question
Write the formula for sodium nitrite using Na⁺ and NO₂⁻.
Answer
NaNO₂. One nitrite ion balances one sodium ion. Keep NO₂⁻ intact; NO₃⁻ would be nitrate.
Card 56
Question
Repair NH₄SO₄ as the formula for ammonium sulfate, using NH₄⁺ and SO₄²⁻.
Answer
(NH₄)₂SO₄. Two whole ammonium ions are required to balance one sulfate ion; the 2 goes outside the ammonium parentheses.
56 cards
Ionic Compound Naming Flashcards: Names, Formulas & Charge Balance
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