Write the chemical formulas for these polyatomic ions: 1. sulfate 2. phosphate 3. carbonate 4. hydroxide 5. nitrate 6. ammonium 1of 51
Answers: 1. SO 4 2 2. PO 4 3 3. CO 3 2 4. OH 5. NO 3 6. NH 4 + 2of 51
Worksheet: Section 9.2, 1 6 Read 9.3 3of 51
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9.2 Naming and Writing Formulas for Ionic Compounds A recipe is a formula for the sauce a complete list of ingredients and their proportions. Chemistry also uses formulas. Once you know the rules, you can write the formula for any chemical compound. 5of 49
6. Apply the rules for naming and writing formulas for binary ionic compounds. 7. Apply the rules for naming and writing chemical formulas for compounds with polyatomic ions (tertiary ionic compounds) 6of 51
9.2 Naming and Writing Formulas for Ionic Compounds > Binary Ionic Compounds Binary Ionic Compounds How are the names of binary ionic compounds determined? How do you write the formulas for binary ionic compounds? 7 of 49
Memorize ALL the rules for each day s lesson as you go along or you will be in danger of getting lost by the end of the chapter! 8of 51
Naming and Writing Binary Ionic Compounds Composed of two elements: Ionic compounds and molecular compounds are named differently!!! Ionic compounds The charges MUST BALANCE Write metal ion first Roman Numerals = charge of ion Reduce to lowest whole number ratio Molecular compounds (preview of tomorrow) Charges do not balance (they do not form ions; they share electrons) Prefixes signify the number of each atom in the compound 9of 51
Steps: 1. Write the ions with their charges 2. Balance the charges by adjusting the subscripts (criss cross method) 3. DO NOT WRITE CHARGES IN YOUR FINAL ANSWER 10 of 51
How would you write the formula for Iron (III) oxide? Fe 2 O 3 11 of 51
Which of the following is a nonmetal? A. iron B. silver C. oxygen D. copper 12 of 51
What is the chemical formula for sodium chloride? A. NaCl B. Na 2 Cl 2 C. ClNa D. Cl 2 Na 2 13 of 51
What is the chemical formula for lithium oxide? A. LiO 2 B. Li 2 O C. OLi 2 D. O 2 Li 14 of 51
What is the chemical formula for cesium sulfide? A. CsS 2 B. Cs 2 S C. CsS D. S 2 Cs 15 of 51
What is the chemical formula for strontium oxide? A. SrO 2 B. SrO C. Sr 2 O D. OSr 16 of 51
Naming binary ionic compounds 1. Write the metal cation first 2. Add the ide suffix to the non metal anion 3. If there is a transition metal cation or Pb or Sn be sure to determine the charge on the ion and write the correct Roman numeral. Cadmium (Cd), Zinc (Zn), and Silver (Ag) do not need Roman numerals because they only form one ion. 17 of 51
What is the name of CuS? A. copper sulfur B. copper sulfide C. copper(ii) sulfide D. copper(i) sulfide 18 of 51
What is the name of Cu 2 O? A. copper oxygen B. copper oxide C. copper (II) oxide D. copper (I) oxide 19 of 51
What is the name of SnF 2 A. tin fluorine B. tin fluoride C. tin (II) fluoride D. tin (I) fluoride 20 of 51
9.2 Naming and Writing Formulas for Ionic Compounds > Binary Ionic Compounds Tin(II) sulfide, or SnF 2, is added to toothpastes to prevent cavities. 21 of 49
What is the name of SnS 2 A. tin sulfur B. tin sulfide C. tin (II) sulfide D. tin (IV) sulfide 22 of 51
9.2 Naming and Writing Formulas for Ionic Compounds > Binary Ionic Compounds Tin(IV) sulfide, or SnS 2, is used in glazes for porcelain fixtures and dishes. 23 of 49
Writing ionic compound formula units Non metal ions end in ide If there is a transition metal with more than one charge you MUST use a Roman numeral. Including Sn and Pb, excluding Ag, Cd, Zn Remember the Roman numeral determines the CHARGE of the ion, not the number of ions in the compound YOU MUST determine the charge of the cation BEFORE writing a Roman numeral Group 1A 3A cations (+ Ag, Cd, Zn)do NOT need a Roman numeral 24 of 51
Compounds with polyatomic ions 1. Write ion & polyatomic ions with their charges 2. Balance the charges of the ions 3. Put parentheses around the polyatomic ion if you need more than one to balance the charge. Do not use parentheses if you need only one polyatomic ion. 25 of 51
Example magnesium hydroxide 26 of 51
Naming compounds with polyatomic ions You must recognize the polyatomic ion Determine charge of anion to figure out Roman numeral (charge) for transition metals Learn your flashcards Example: K 2 CO 3 potassium carbonate 27 of 51
What is the name of AlF3? A. aluminum fluoride B. aluminum fluorine C. aluminum(i) fluorine D. aluminum(ii) fluoride 28 of 51
What is the name of FeS? A. Iron sulfur B. Iron sulfide C. Iron(II) sulfide D. Iron(III) sulfide 29 of 51
What is the name of CaO? A. calcium oxide B. calcium(i) oxide C. calcium(ii) oxide D. calcium oxygenide 30 of 51
What is the name of Fe 2 O 3? A. iron oxide B. iron(i) oxide C. iron(ii) oxide D. iron(iii) oxide 31 of 51
9.2 Naming and Writing Formulas for Ionic Compounds > Binary Ionic Compounds Hematite, a common ore of iron, contains iron (III) oxide. The balanced formula is Fe 2 O 3. 32 of 49
What is the formula for sodium hydroxide? NaOH Magnesium Phosphate? Mg 3 (PO 4 ) 2 33 of 51
What is the correct formula for potassium sulfate? A. KSO 4 B. K 2 SO 4 C. K(SO 4 ) D. K(SO 4 ) 2 34 of 51
What is the correct formula for calcium carbonate? A. CaCO 3 B. Ca(CO 3 ) C. Ca 2 (CO 3 ) D. Ca(CO 3 ) 2 35 of 51
9.2 Naming and Writing Formulas for Ionic Compounds > Compounds With Polyatomic Ions Oysters produce calcium carbonate to form their shells and sometimes pearls. 36 of 49
Use table 9.3 on page 257: What is the correct formula for sodium hypochlorite A. NaClO B. Na 2 ClO C. Na(ClO) 1 D. Na(ClO) 2 37 of 51
9.2 Naming and Writing Formulas for Ionic Compounds > Compounds With Polyatomic Ions Sodium hypochlorite (NaClO) is used as a disinfectant for swimming pools. The metallic cation in this compound is sodium (Na + ) so the polyatomic ion must be ClO. 38 of 49
Use table 9.3 on page 257: What is the correct formula for tin (IV) dichromate? A. SnCr 2 O 7 B. Sn 2 Cr 2 O 7 C. Sn 2 (Cr 2 O 7 ) D. Sn(Cr 2 O 7 ) 2 39 of 51
Naming compounds with polyatomic ions You must recognize the polyatomic ion Determine charge of anion to figure out Roman numeral (charge) for transition metals Learn your flashcards Example: K 2 CO 3 potassium carbonate 40 of 51
What is the name of Li 2 CO 3? A. lithium carbon nitride B. lithium carbonate C. lithium cyanide 41 of 51
Name PbSO 4 A. lead sulfate B. lead(i) sufate C. lead(ii) sulfite D. lead(ii) sulfate 42 of 51
9.2 Naming and Writing Formulas for Ionic Compounds > Compounds With Polyatomic Ions Lead(II)sulfate is an important component of an automobile battery. 43 of 29
What is the name of Al(OH) 3? A. aluminum oxyhydride B. aluminum hydrogen oxide C. aluminum hydroxide 44 of 51
Name Sn 3 (PO 4 ) 2 A. selenium potassium oxide B. tin phosphate C. tin phosphide D. tin (II) phosphate 45 of 51
What is the name of Na 2 CO 3? A. sodium carbonate B. disodium carbonate C. sodium chromate D. sodium(ii) carbonate 46 of 51
What is the name of (NH 4 ) 2 CO 3? A. nitrogen hydrocarbonate B. nitrogen hydrogen carbonate C. ammonium carbonate 47 of 51
What is the charge of the ion of sulfur? A. 2+ B. 1 C. 2 D. 0 48 of 51
Which of the following is NOT a cation? A. iron(iii) ion B. calcium ion C. sulfate D. mercurous ion 49 of 51
An ate or ite at the end of a compound name usually indicates that the compound contains. A. fewer electrons than protons B. only two elements C. neutral molecules D. a polyatomic anion 50 of 51
Read 9.3 WS: Practice Problems 9.2, Qs 1 6 51 of 51