Question

1. basic ionic naming and formulas - in an ionic compound, the charges must sum to ______. (___/2 pts)

in an ionic compound, the (metal or nonmetal) must come first. the nonmetal ending must change to -_____.
name the following ionic compounds write the formulas for the following compounds (_____/6 pts)
srbr₂ sodium selenide
beo rubidium iodide
al₂s₃ calcium phosphide

1. transition metal naming and formula writing - think carefully about how these elements are different, when to use roman numerals, and what a roman numeral means.

which elements outside the transition metals get roman numerals?_______________________. (___/1 pts)
what elements are within the transition metals that do not get roman numerals?_________________________.
name the following ionic compounds write the formulas for the following compounds (_____8 pts)
cus zinc oxide
pbo₂ tin (iv) sulfide
agcl iron (ii) nitride
nii₂ cobalt (iii) selenide

1. polyatomic naming and formula writing

when do you need parentheses when writing polyatomic formulas? _______________________ (___/1 pt)
write the formulas for the following compounds name the following ionic compounds (_____8 pts)
potassium permanganate cr(no₃)₂
aluminum sulfite nahco₃
iron (iii) bisulfate mg₃(po₄)₂
calcium oxalate nh₄oh

Answer:

Question 4 (Basic Ionic Naming and Formulas)

Part 1: Fill in the Blanks

• In an ionic compound, the charges must sum to $\boldsymbol{0}$ (neutral).
• In an ionic compound, the $\boldsymbol{\text{metal}}$ must come first.
• The nonmetal ending must change to $\boldsymbol{-ide}$.

Part 2: Name the Ionic Compounds

• $\ce{SrBr_{2}}$: Strontium bromide (Sr is +2, Br is -1; name: metal + nonmetal -ide)
• $\ce{BeO}$: Beryllium oxide (Be is +2, O is -2; name: metal + nonmetal -ide)
• $\ce{Al_{2}S_{3}}$: Aluminum sulfide (Al is +3, S is -2; name: metal + nonmetal -ide)

Part 3: Write the Formulas

• Sodium selenide: $\ce{Na_{2}Se}$ (Na is +1, Se is -2; crisscross charges: $1\times2$ for Na, $2\times1$ for Se → $\ce{Na_{2}Se}$)
• Rubidium iodide: $\ce{RbI}$ (Rb is +1, I is -1; charges balance → $\ce{RbI}$)
• Calcium phosphide: $\ce{Ca_{3}P_{2}}$ (Ca is +2, P is -3; crisscross charges: $2\times3$ for Ca, $3\times2$ for P → $\ce{Ca_{3}P_{2}}$)

Question 5 (Transition Metal Naming and Formula Writing)

Part 1: Fill in the Blanks

• Elements outside transition metals (main group metals with fixed charges, e.g., Group 1, 2, Al, Zn, Ag) do not get roman numerals (except for variable charge main group metals, but most fixed).
• Transition metals that do not get roman numerals: $\boldsymbol{\text{Zn, Ag, Cd}}$ (fixed +2, +1, +2 charges, respectively).

Part 2: Name the Ionic Compounds

• $\ce{CuS}$: Copper(II) sulfide (Cu is +2, S is -2; roman numeral for Cu’s charge)
• $\ce{PbO_{2}}$: Lead(IV) oxide (Pb is +4, O is -2; roman numeral for Pb’s charge)
• $\ce{AgCl}$: Silver chloride (Ag is +1, fixed charge → no roman numeral)
• $\ce{NiI_{2}}$: Nickel(II) iodide (Ni is +2, I is -1; roman numeral for Ni’s charge)

Part 3: Write the Formulas

• Zinc oxide: $\ce{ZnO}$ (Zn is +2, O is -2; charges balance)
• Tin(IV) sulfide: $\ce{SnS_{2}}$ (Sn is +4, S is -2; crisscross: $4\times1$ for Sn, $2\times2$ for S → $\ce{SnS_{2}}$)
• Iron(II) nitride: $\ce{Fe_{3}N_{2}}$ (Fe is +2, N is -3; crisscross: $2\times3$ for Fe, $3\times2$ for N → $\ce{Fe_{3}N_{2}}$)
• Cobalt(III) selenide: $\ce{Co_{2}Se_{3}}$ (Co is +3, Se is -2; crisscross: $3\times2$ for Co, $2\times3$ for Se → $\ce{Co_{2}Se_{3}}$)

Question 6 (Polyatomic Naming and Formula Writing)

Part 1: Fill in the Blank

• Parentheses are needed when the polyatomic ion has a subscript greater than 1 (e.g., $\ce{Ca(OH)_{2}}$: 2 OH⁻ ions).

Part 2: Write the Formulas

• Potassium permanganate: $\ce{KMnO_{4}}$ (K⁺ + $\ce{MnO_{4}^{-}}$)
• Aluminum sulfite: $\ce{Al_{2}(SO_{3})_{3}}$ (Al³⁺ + $\ce{SO_{3}^{2-}}$; crisscross: $3\times2$ for Al, $2\times3$ for $\ce{SO_{3}^{2-}}$ → $\ce{Al_{2}(SO_{3})_{3}}$)
• Iron(III) bisulfate: $\ce{Fe(HSO_{4})_{3}}$ (Fe³⁺ + $\ce{HSO_{4}^{-}}$; 3 $\ce{HSO_{4}^{-}}$ to balance +3)
• Calcium oxalate: $\ce{CaC_{2}O_{4}}$ (Ca²⁺ + $\ce{C_{2}O_{4}^{2-}}$; charges balance)

Part 3: Name the Ionic Compounds

• $\ce{Cr(NO_{3})_{2}}$: Chromium(II) nitrate (Cr is +2, $\ce{NO_{3}^{-}}$ is -1; name: metal (roman numeral) + polyatomic ion)
• $\ce{NaHCO_{3}}$: Sodium bicarbonate (or sodium hydrogen carbonate) (Na⁺ + $\ce{HCO_{3}^{-}}$)
• $\ce{Mg_{3}(PO_{4})_{2}}$: Magnesium phosphate (Mg is +2, $\ce{PO_{4}^{3-}}$ is -3; name: metal + polyatomic ion)
• $\ce{NH_{4}OH}$: Ammonium hydroxide ( $\ce{NH_{4}^{+}}$ + $\ce{OH^{-}}$)

Final Answers (Key Parts)

Question 4 Blanks:

• Charges sum to: $\boldsymbol{0}$
• First element: $\boldsymbol{\text{metal}}$
• Nonmetal ending: $\boldsymbol{-ide}$

Question 4 Names:

• $\ce{SrBr_{2}}$: Strontium bromide
• $\ce{BeO}$: Beryllium oxide
• $\ce{Al_{2}S_{3}}$: Aluminum sulfide

Question 4 Formulas:

• Sodium selenide: $\boldsymbol{\ce{Na_{2}Se}}$
• Rubidium iodide: $\boldsymbol{\ce{RbI}}$
• Calcium phosphide: $\boldsymbol{\ce{Ca_{3}P_{2}}}$

Question 5 Blanks:

• Elements outside transition metals with fixed charges (e.g., Group 1, 2, Al, Zn, Ag) do not get roman numerals.
• Transition metals without roman numerals: $\boldsymbol{\text{Zn, Ag, Cd}}$

Question 5 Names:

• $\ce{CuS}$: Copper(II) sulfide
• $\ce{PbO_{2}}$: Lead(IV) oxide
• $\ce{AgCl}$: Silver chloride
• $\ce{NiI_{2}}$: Nickel(II) iodide

Question 5 Formulas:

• Zinc oxide: $\boldsymbol{\ce{ZnO}}$
• Tin(IV) sulfide: $\boldsymbol{\ce{SnS_{2}}}$
• Iron(II) nitride: $\boldsymbol{\ce{Fe_{3}N_{2}}}$
• Cobalt(III) selenide: $\boldsymbol{\ce{Co_{2}Se_{3}}}$

Question 6 Parentheses:

• Parentheses when polyatomic ion subscript > 1.

Question 6 Formulas:

• Potassium permanganate: $\boldsymbol{\ce{KMnO_{4}}}$
• Aluminum sulfite: $\boldsymbol{\ce{Al_{2}(SO_{3})_{3}}}$
• Iron(III) bisulfate: $\boldsymbol{\ce{Fe(HSO_{4})_{3}}}$
• Calcium oxalate: $\boldsymbol{\ce{CaC_{2}O_{4}}}$

Question 6 Names:

• $\ce{Cr(NO_{3})_{2}}$: Chromium(II) nitrate
• $\ce{NaHCO_{3}}$: Sodium bicarbonate
• $\ce{Mg_{3}(PO_{4})_{2}}$: Magnesium phosphate
• $\ce{NH_{4}OH}$: Ammonium hydroxide