11/13/2010 Naming and Writing Formulas A Review Activity for Panther-Chemists

11/13/2010 What do you want to do? Determine whether a compound is ionic or covalent Determine whether a compound is ionic or covalent Write a chemical formula given a word name Write a word name given a chemical formula Translate a chemical reaction from symbols to words Translate a chemical reaction from symbols to words Translate a chemical reaction from words to symbols Translate a chemical reaction from words to symbols

11/13/2010 How to determine whether a compound is ionic or covalent First, grab your periodic table and ion sheet. When you are ready, you may continue…

11/13/2010 Find the zigzag line on your periodic table (it is in the “p-block”) How to determine whether a compound is ionic or covalent

11/13/2010 Recall that metals are located to the left of the zigzag line 11/13/2010 How to determine whether a compound is ionic or covalent

11/13/2010 …and nonmetals are located to the left of the zigzag 11/13/2010 How to determine whether a compound is ionic or covalent

11/13/2010 If a compound is made of a metal and nonmetal, it is ionic; the metal ion always appears first in a chemical name 11/13/2010 How to determine whether a compound is ionic or covalent

11/13/2010 If a compound is made of all nonmetals, it is covalent 11/13/2010 How to determine whether a compound is ionic or covalent

11/13/2010 How to determine whether a compound is ionic or covalent Practice Problems: Determine whether each formula is ionic or covalent Calcium chloride

11/13/2010 How to determine whether a compound is ionic or covalent Practice Problems: Determine whether each formula is ionic or covalent Calcium chloride Ionic Ca Cl

11/13/2010 How to determine whether a compound is ionic or covalent Practice Problems: Determine whether each formula is ionic or covalent Aluminum phosphate

11/13/2010 How to determine whether a compound is ionic or covalent Practice Problems: Determine whether each formula is ionic or covalent Aluminum phosphate Ionic Al

11/13/2010 How to determine whether a compound is ionic or covalent Practice Problems: Determine whether each formula is ionic or covalent Carbon tetrachloride

11/13/2010 How to determine whether a compound is ionic or covalent Practice Problems: Determine whether each formula is ionic or covalent Carbon tetrachloride Covalent C Cl

11/13/2010 How to determine whether a compound is ionic or covalent Practice Problems: Determine whether each formula is ionic or covalent Mercury (II) sulfate

11/13/2010 How to determine whether a compound is ionic or covalent Practice Problems: Determine whether each formula is ionic or covalent Mercury (II) sulfate Ionic Hg

11/13/2010 How to determine whether a compound is ionic or covalent Practice Problems: Determine whether each formula is ionic or covalent Ammonium chloride

11/13/2010 Practice Problems: Determine whether each formula is ionic or covalent Ammonium chloride Ionic; because ammonium is a positively charged ion (polyatomic cation found on ion sheet) 11/13/2010 How to determine whether a compound is ionic or covalent

11/13/2010 How to determine whether a compound is ionic or covalent Practice Problems: Determine whether each formula is ionic or covalent Disulfur pentoxide

11/13/2010 How to determine whether a compound is ionic or covalent Practice Problems: Determine whether each formula is ionic or covalent Disulfur pentoxide Covalent S O

11/13/2010 How to write a formula given a name First, grab your periodic table and ion sheet. When you are ready, you may continue…

11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent ; if covalent, use prefixes and stop here. If ionic, continue through step 5. [click here if you need a refresher on how to decide whether a compound is ionic or covalent]here

11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent; if covalent, use prefixes and stop here. If ionic, continue through step 5. Step 2: Split name into two pieces, usually after the first word

11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent; if covalent, use prefixes and stop here. If ionic, continue through step 5. Step 2: Split name into two pieces, usually after the first word Step 3: Write the ions for each piece

11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent; if covalent, use prefixes and stop here. If ionic, continue through step 5. Step 2: Split name into two pieces, usually after the first word Step 3: Write the ions for each piece Step 4: Drop + and – signs, then criss-cross

11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent; if covalent, use prefixes and stop here. If ionic, continue through step 5. Step 2: Split name into two pieces, usually after the first word Step 3: Write the ions for each piece Step 4: Drop + and – signs, then criss-cross Step 5: Add parenthesis if needed and see if the formula can be reduced

11/13/2010 How to write a formula given a name Ready for practice? Try to write the given formulas. When you have an answer, click through to check your work. Continue to the next page…

11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent ; if covalent, use prefixes and stop here. If ionic, continue through step 5. Step 2: Split name into two pieces, usually after the first word Step 3: Write the ions for each piece Step 4: Drop + and – signs, then criss-cross Step 5: Add parenthesis if needed and see if the formula can be reduced PRACTICE PROBLEMS: Write the formula for barium chloride.

11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent ; if covalent, use prefixes and stop here. If ionic, continue through step 5. Step 2: Split name into two pieces, usually after the first word Step 3: Write the ions for each piece Step 4: Drop + and – signs, then criss-cross Step 5: Add parenthesis if needed and see if the formula can be reduced PRACTICE PROBLEMS: Write the formula for barium chloride. Step 1: Ionic, because the first part of the name, barium, is a metal

11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent ; if covalent, use prefixes and stop here. If ionic, continue through step 5. Step 2: Split name into two pieces, usually after the first word Step 3: Write the ions for each piece Step 4: Drop + and – signs, then criss-cross Step 5: Add parenthesis if needed and see if the formula can be reduced PRACTICE PROBLEMS: Write the formula for barium chloride. Step 1: Ionic, because the first part of the name, barium, is a metal Step 2: barium / chloride

11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent ; if covalent, use prefixes and stop here. If ionic, continue through step 5. Step 2: Split name into two pieces, usually after the first word Step 3: Write the ions for each piece Step 4: Drop + and – signs, then criss-cross Step 5: Add parenthesis if needed and see if the formula can be reduced PRACTICE PROBLEMS: Write the formula for barium chloride. Step 1: Ionic, because the first part of the name, barium, is a metal Step 2: barium / chloride Step 3: Ba 2+ / Cl - (note: use your periodic table to determine charges of individual elements; use your ion sheet to write out polyatomic ions)

11/13/2010 PRACTICE PROBLEMS: Write the formula for barium chloride. Step 1: Ionic, because the first part of the name, barium, is a metal Step 2: barium / chloride Step 3: Ba 2+ / Cl - (note: use your periodic table to determine charges of individual elements; use your ion sheet to write out polyatomic ions) Step 4: Ba Cl 11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent ; if covalent, use prefixes and stop here. If ionic, continue through step 5. Step 2: Split name into two pieces, usually after the first word Step 3: Write the ions for each piece Step 4: Drop + and – signs, then criss-cross Step 5: Add parenthesis if needed and see if the formula can be reduced 2 + -

11/13/2010 PRACTICE PROBLEMS: Write the formula for barium chloride. Step 1: Ionic, because the first part of the name, barium, is a metal Step 2: barium / chloride Step 3: Ba 2+ / Cl - (note: use your periodic table to determine charges of individual elements; use your ion sheet to write out polyatomic ions) Step 4: Step 5: Parenthesis are only needed when a polyatomic ion has a subscript (number) greater than 1. The ion ratio 1Ba:2Cl can not be reduced. BaCl 11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent ; if covalent, use prefixes and stop here. If ionic, continue through step 5. Step 2: Split name into two pieces, usually after the first word Step 3: Write the ions for each piece Step 4: Drop + and – signs, then criss-cross Step 5: Add parenthesis if needed and see if the formula can be reduced 2

11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent ; if covalent, use prefixes and stop here. If ionic, continue through step 5. Step 2: Split name into two pieces, usually after the first word Step 3: Write the ions for each piece Step 4: Drop + and – signs, then criss-cross Step 5: Add parenthesis if needed and see if the formula can be reduced PRACTICE PROBLEMS: Write the formula for copper (II) sulfate.

11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent ; if covalent, use prefixes and stop here. If ionic, continue through step 5. Step 2: Split name into two pieces, usually after the first word Step 3: Write the ions for each piece Step 4: Drop + and – signs, then criss-cross Step 5: Add parenthesis if needed and see if the formula can be reduced PRACTICE PROBLEMS: Write the formula for copper (II) sulfate. Step 1: Ionic, because the first part of the name, copper, is a metal

11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent ; if covalent, use prefixes and stop here. If ionic, continue through step 5. Step 2: Split name into two pieces, usually after the first word Step 3: Write the ions for each piece Step 4: Drop + and – signs, then criss-cross Step 5: Add parenthesis if needed and see if the formula can be reduced PRACTICE PROBLEMS: Write the formula for copper (II) sulfate. Step 1: Ionic, because the first part of the name, copper, is a metal Step 2: copper (II) / sulfate

11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent ; if covalent, use prefixes and stop here. If ionic, continue through step 5. Step 2: Split name into two pieces, usually after the first word Step 3: Write the ions for each piece Step 4: Drop + and – signs, then criss-cross Step 5: Add parenthesis if needed and see if the formula can be reduced PRACTICE PROBLEMS: Write the formula for copper (II) sulfate. Step 1: Ionic, because the first part of the name, copper, is a metal Step 2: copper (II) / sulfate Step 3: Cu 2+ / SO 4 2-

11/13/2010 PRACTICE PROBLEMS: Write the formula for copper (II) sulfate. Step 1: Ionic, because the first part of the name, copper (II), is a metal Step 2: copper (II) / sulfate Step 3: Cu 2+ / SO 4 2- (note: the Roman numeral (II) indicates the charge of the copper ion, 2+; the ‘sulfate’ ion is on your ion sheet) Step 4: Notice how nothing happened to the “4” on the sulfate ion. DO NOT modify numbers that are AREADY there as subscripts (numbers on the bottom) before the criss-cross (already there at Step 3 in ion form). Cu SO 4 11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent ; if covalent, use prefixes and stop here. If ionic, continue through step 5. Step 2: Split name into two pieces, usually after the first word Step 3: Write the ions for each piece Step 4: Drop + and – signs, then criss-cross Step 5: Add parenthesis if needed and see if the formula can be reduced

11/13/2010 Cu SO 4 PRACTICE PROBLEMS: Write the formula for copper (II) sulfate. Step 1: Ionic, because the first part of the name, copper (II), is a metal Step 2: copper (II) / sulfate Step 3: Cu 2+ / SO 4 2- (note: the Roman numeral (II) indicates the charge of the copper ion, 2+; the ‘sulfate’ ion is on your ion sheet) Step 4: Step 5: For now, you will need parenthesis around the sulfate ion because it is a polyatomic ion that received a subscript greater than 1. Also, the ion ratio is 2Cu: 2 SO 4 which can reduce to 1:1… now you can remove the parenthesis ( ) 11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent ; if covalent, use prefixes and stop here. If ionic, continue through step 5. Step 2: Split name into two pieces, usually after the first word Step 3: Write the ions for each piece Step 4: Drop + and – signs, then criss-cross Step 5: Add parenthesis if needed and see if the formula can be reduced 22

11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent ; if covalent, use prefixes and stop here. If ionic, continue through step 5. Step 2: Split name into two pieces, usually after the first word Step 3: Write the ions for each piece Step 4: Drop + and – signs, then criss-cross Step 5: Add parenthesis if needed and see if the formula can be reduced PRACTICE PROBLEMS: Write the formula for sulfur trioxide.

11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent ; if covalent, use prefixes and stop here. If ionic, continue through step 5. Step 2: Split name into two pieces, usually after the first word Step 3: Write the ions for each piece Step 4: Drop + and – signs, then criss-cross Step 5: Add parenthesis if needed and see if the formula can be reduced PRACTICE PROBLEMS: Write the formula for sulfur trioxide. Step 1: Covalent, because the formula contains all nonmetals… 1 sulfur and three oxygens = SO 3 … no criss-crossing for covalent compounds. 1 = mono 2 = di 3 = tri 4 = tetra 5 = penta 6 = hexa 7 = hepta 8 = octa 9 = nona 10 = deca

11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent ; if covalent, use prefixes and stop here. If ionic, continue through step 5. Step 2: Split name into two pieces, usually after the first word Step 3: Write the ions for each piece Step 4: Drop + and – signs, then criss-cross Step 5: Add parenthesis if needed and see if the formula can be reduced PRACTICE PROBLEMS: Write the formula for calcium phosphate.

11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent ; if covalent, use prefixes and stop here. If ionic, continue through step 5. Step 2: Split name into two pieces, usually after the first word Step 3: Write the ions for each piece Step 4: Drop + and – signs, then criss-cross Step 5: Add parenthesis if needed and see if the formula can be reduced PRACTICE PROBLEMS: Write the formula for calcium phosphate. Step 1: Ionic, because the first part of the name, calcium, is a metal

11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent ; if covalent, use prefixes and stop here. If ionic, continue through step 5. Step 2: Split name into two pieces, usually after the first word Step 3: Write the ions for each piece Step 4: Drop + and – signs, then criss-cross Step 5: Add parenthesis if needed and see if the formula can be reduced PRACTICE PROBLEMS: Write the formula for calcium phosphate. Step 1: Ionic, because the first part of the name, calcium, is a metal Step 2: calcium / phosphate

11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent ; if covalent, use prefixes and stop here. If ionic, continue through step 5. Step 2: Split name into two pieces, usually after the first word Step 3: Write the ions for each piece Step 4: Drop + and – signs, then criss-cross Step 5: Add parenthesis if needed and see if the formula can be reduced PRACTICE PROBLEMS: Write the formula for calcium phosphate. Step 1: Ionic, because the first part of the name, calcium, is a metal Step 2: calcium / phosphate Step 3: Ca 2+ / PO 4 3-

11/13/2010 PRACTICE PROBLEMS: Write the formula for calcium phosphate. Step 1: Ionic, because the first part of the name, calcium, is a metal Step 2: calcium / phosphate Step 3: Ca 2+ / PO 4 3- Step 4: Ca PO 4 11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent ; if covalent, use prefixes and stop here. If ionic, continue through step 5. Step 2: Split name into two pieces, usually after the first word Step 3: Write the ions for each piece Step 4: Drop + and – signs, then criss-cross Step 5: Add parenthesis if needed and see if the formula can be reduced

11/13/2010 PRACTICE PROBLEMS: Write the formula for calcium phosphate. Step 1: Ionic, because the first part of the name, calcium, is a metal Step 2: calcium / phosphate Step 3: Ca 2+ / PO 4 3- Step 4: Step 5: Because phosphate is a polyatomic ion that received a subscript greater than 1, use parenthesis. The ion ratio is 3Ca: 2PO 4 ; you can not reduce this ratio. Ca (PO 4 ) 11/13/2010 How to write a formula given a name Step 1: Determine whether the compound is ionic or covalent ; if covalent, use prefixes and stop here. If ionic, continue through step 5. Step 2: Split name into two pieces, usually after the first word Step 3: Write the ions for each piece Step 4: Drop + and – signs, then criss-cross Step 5: Add parenthesis if needed and see if the formula can be reduced 23

11/13/2010 How to write a name from a formula First, grab your periodic table and ion sheet. When you are ready, you may continue…

11/13/2010 How to write a name from a formula Step 1: Determine whether the formula is ionic or covalent [if you need help with this step, click here]click here Step 2: Apply appropriate naming rules… -If covalent, use prefixes except for ‘mono’ on first element -If ionic, split formula into 2 pieces (usually split after first ion). First ion gets its ‘regular’ name… 2 nd ion changes ending to – ide if monatomic, or is found on anion side of ion sheet if polyatomic. Check cations on ion sheet for Roman numerals.

11/13/2010 How to write a name from a formula Step 1: Determine whether the formula is ionic or covalent Step 2: Apply appropriate naming rules… -If covalent, use prefixes except for ‘mono’ on first element -If ionic, split formula into 2 pieces (usually split after first ion). First ion gets its ‘regular’ name… 2 nd ion changes ending to –ide if monatomic, or is found on anion side of ion sheet if polyatomic. Check cations on ion sheet for Roman numerals. Practice problem: Name Cu(OH) 2

11/13/2010 How to write a name from a formula Step 1: Determine whether the formula is ionic or covalent Step 2: Apply appropriate naming rules… -If covalent, use prefixes except for ‘mono’ on first element -If ionic, split formula into 2 pieces (usually split after first ion). First ion gets its ‘regular’ name… 2 nd ion changes ending to –ide if monatomic, or is found on anion side of ion sheet if polyatomic. Check cations on ion sheet for Roman numerals. Practice problem: Name Cu(OH) 2 Step 1: Ionic

11/13/2010 How to write a name from a formula Step 1: Determine whether the formula is ionic or covalent Step 2: Apply appropriate naming rules… -If covalent, use prefixes except for ‘mono’ on first element -If ionic, split formula into 2 pieces (usually split after first ion). First ion gets its ‘regular’ name… 2 nd ion changes ending to –ide if monatomic, or is found on anion side of ion sheet if polyatomic. Check cations on ion sheet for Roman numerals. Practice problem: Name Cu(OH) 2 Step 1: Ionic Step 2: Cu / (OH) 2 First part is named ‘COPPER’ Second part is found on anion side of ion sheet, called ‘HYDROXIDE’ According to cations on ion sheet, copper needs a Roman numeral (can be I or II) Backwards criss-cross to determine original ion charges in order to identify correct Roman numeral Check anion on ion sheet to verify ions are correct Copper used to have 2+ charge, therefore, this is copper (II) hydroxide Cu OH( ) 2 + -

11/13/2010 How to write a name from a formula Step 1: Determine whether the formula is ionic or covalent Step 2: Apply appropriate naming rules… -If covalent, use prefixes except for ‘mono’ on first element -If ionic, split formula into 2 pieces (usually split after first ion). First ion gets its ‘regular’ name… 2 nd ion changes ending to –ide if monatomic, or is found on anion side of ion sheet if polyatomic. Check cations on ion sheet for Roman numerals. Practice problem: Name NO 2

11/13/2010 How to write a name from a formula Step 1: Determine whether the formula is ionic or covalent Step 2: Apply appropriate naming rules… -If covalent, use prefixes except for ‘mono’ on first element -If ionic, split formula into 2 pieces (usually split after first ion). First ion gets its ‘regular’ name… 2 nd ion changes ending to –ide if monatomic, or is found on anion side of ion sheet if polyatomic. Check cations on ion sheet for Roman numerals. Practice problem: Name NO 2 Step 1: Covalent Step 2: Do not use the prefix ‘mono’ for first element… 1N = nitrogen; 2O = dioxide… therefore, this is nitrogen dioxide

11/13/2010 How to write a name from a formula Step 1: Determine whether the formula is ionic or covalent Step 2: Apply appropriate naming rules… -If covalent, use prefixes except for ‘mono’ on first element -If ionic, split formula into 2 pieces (usually split after first ion). First ion gets its ‘regular’ name… 2 nd ion changes ending to –ide if monatomic, or is found on anion side of ion sheet if polyatomic. Check cations on ion sheet for Roman numerals. Practice problem: Name N 2 O 5

11/13/2010 How to write a name from a formula Step 1: Determine whether the formula is ionic or covalent Step 2: Apply appropriate naming rules… -If covalent, use prefixes except for ‘mono’ on first element -If ionic, split formula into 2 pieces (usually split after first ion). First ion gets its ‘regular’ name… 2 nd ion changes ending to –ide if monatomic, or is found on anion side of ion sheet if polyatomic. Check cations on ion sheet for Roman numerals. Practice problem: Name N 2 O 5 Step 1: Covalent Step 2: Do not use the prefix ‘mono’ for first element… 1N = nitrogen; 2O = dioxide… therefore, this is nitrogen dioxide

11/13/2010 When a polyatomic ion DOES NOT have parenthesis, you MAY NOT move its subscript for a backwards criss-cross! Practice problem: Name FePO 4 Step 1: Ionic Step 2: Fe / PO 4 First part is named ‘IRON’ Second part is found on anion side of ion sheet, called ‘PHOSPHATE’ According to cations on ion sheet, iron needs a Roman numeral (can be II or III) Backwards criss-cross to determine original ion charges … note there are no parenthesis around phosphate so the 4 stays in place: Fe / PO 4 Check anion on ion sheet to verify ions are correct… phosphate’s charge of 3- must have cancelled out… the original formula must have looked like this: Fe 3 (PO 4 ) 3 Iron used to have 3+ charge, therefore, this is iron (III) phosphate 11/13/2010 How to write a name from a formula Step 1: Determine whether the formula is ionic or covalent Step 2: Apply appropriate naming rules… -If covalent, use prefixes except for ‘mono’ on first element -If ionic, split formula into 2 pieces (usually split after first ion). First ion gets its ‘regular’ name… 2 nd ion changes ending to –ide if monatomic, or is found on anion side of ion sheet if polyatomic. Check cations on ion sheet for Roman numerals.

11/13/2010 How to write a name from a formula Step 1: Determine whether the formula is ionic or covalent Step 2: Apply appropriate naming rules… -If covalent, use prefixes except for ‘mono’ on first element -If ionic, split formula into 2 pieces (usually split after first ion). First ion gets its ‘regular’ name… 2 nd ion changes ending to –ide if monatomic, or is found on anion side of ion sheet if polyatomic. Check cations on ion sheet for Roman numerals. Practice problem: Name Al 2 O 3

11/13/2010 How to write a name from a formula Step 1: Determine whether the formula is ionic or covalent Step 2: Apply appropriate naming rules… -If covalent, use prefixes except for ‘mono’ on first element -If ionic, split formula into 2 pieces (usually split after first ion). First ion gets its ‘regular’ name… 2 nd ion changes ending to –ide if monatomic, or is found on anion side of ion sheet if polyatomic. Check cations on ion sheet for Roman numerals. Practice problem: Name Al 2 O 3 Step 1: Ionic Step 2: Al 2 / O 3 First ion is called ‘Aluminum’ Second ion is monatomic so it changes its ending to –ide… ‘oxide’ Aluminum does not need a Roman numeral according to the cations on the ion sheet Therefore, this is called aluminum oxide

11/13/2010 How to translate a chemical reaction from symbols to words First, grab your periodic table and ion sheet. When you are ready, you may continue…

11/13/2010 How to translate a chemical reaction from symbols to words Step 1: Make sure the reaction is balanced. If it is not balanced, take a minute to balance it. Step 2: Recall that coefficients in a reaction indicate the number of moles. When there are ‘invisible 1’ coefficients, translate them as “one mole of…” Step 3: States of matter generally sound best written before a compound; except for ‘gas’, which sounds best after a compound Step 4: Review naming rules if you need a refreshernaming rules Common symbols: (s) = solid → = produces; yields; reacts to form; etc. (l) = liquid → = when heated, produces… (g) or (↑) = gas(aq) = aqueous (dissolved in water; solution) (ppt) or (↓) = precipitate ∆

11/13/2010 How to translate a chemical reaction from symbols to words Step 1: Make sure the reaction is balanced. If it is not balanced, take a minute to balance it. Step 2: Recall that coefficients in a reaction indicate the number of moles. When there are ‘invisible 1’ coefficients, translate them as “one mole of…” Step 3: States of matter generally sound best written before a compound; except for ‘gas’, which sounds best after a compound Step 4: Review naming rules if you need a refreshernaming rules Common symbols: (s) = solid → = produces; yields; reacts to form; etc. (l) = liquid → = when heated, produces… (g) or (↑) = gas(aq) = aqueous (dissolved in water; solution) (ppt) or (↓) = precipitate ∆ Practice Problem: Translate 4Fe(s) + 3O 2 (g) → 2Fe 2 O 3 (s)

11/13/2010 How to translate a chemical reaction from symbols to words Step 1: Make sure the reaction is balanced. If it is not balanced, take a minute to balance it. Step 2: Recall that coefficients in a reaction indicate the number of moles. When there are ‘invisible 1’ coefficients, translate them as “one mole of…” Step 3: States of matter generally sound best written before a compound; except for ‘gas’, which sounds best after a compound Step 4: Review naming rules if you need a refreshernaming rules Common symbols: (s) = solid → = produces; yields; reacts to form; etc. (l) = liquid → = when heated, produces… (g) or (↑) = gas(aq) = aqueous (dissolved in water; solution) (ppt) or (↓) = precipitate ∆ Practice Problem: Translate 4Fe(s) + 3O 2 (g) → 2Fe 2 O 3 (s) Step 1: balanced Step 2, 3, 4: Four moles solid iron plus three moles oxygen gas produce two moles solid iron (III) oxide.

11/13/2010 How to translate a chemical reaction from symbols to words Step 1: Make sure the reaction is balanced. If it is not balanced, take a minute to balance it. Step 2: Recall that coefficients in a reaction indicate the number of moles. When there are ‘invisible 1’ coefficients, translate them as “one mole of…” Step 3: States of matter generally sound best written before a compound; except for ‘gas’, which sounds best after a compound Step 4: Review naming rules if you need a refreshernaming rules Common symbols: (s) = solid → = produces; yields; reacts to form; etc. (l) = liquid → = when heated, produces… (g) or (↑) = gas(aq) = aqueous (dissolved in water; solution) (ppt) or (↓) = precipitate ∆ Practice Problem: Translate C 6 H 12 O 6 (s) + 9O 2 (g) → 6 CO 2 (g) + 6H 2 O(g)

11/13/2010 How to translate a chemical reaction from symbols to words Step 1: Make sure the reaction is balanced. If it is not balanced, take a minute to balance it. Step 2: Recall that coefficients in a reaction indicate the number of moles. When there are ‘invisible 1’ coefficients, translate them as “one mole of…” Step 3: States of matter generally sound best written before a compound; except for ‘gas’, which sounds best after a compound Step 4: Review naming rules if you need a refreshernaming rules Common symbols: (s) = solid → = produces; yields; reacts to form; etc. (l) = liquid → = when heated, produces… (g) or (↑) = gas(aq) = aqueous (dissolved in water; solution) (ppt) or (↓) = precipitate ∆ Practice Problem: Translate C 6 H 12 O 6 (s) + 9O 2 (g) → 6 CO 2 (g) + 6H 2 O(g) Step 1: balanced Step 2, 3, 4: One mole solid sugar plus nine moles oxygen gas react to form six moles carbon dioxide gas and six moles water vapor. It is OK to use the common name of familiar chemicals like sugar, water, ammonia (NH 3 ), etc.

11/13/2010 How to translate a chemical reaction from words to symbols First, grab your periodic table and ion sheet. When you are ready, you may continue…

11/13/2010 How to translate a chemical reaction from words to symbols Step 1: It is helpful to circle or underline chemical formulas first Step 2: Translate chemical names to formulas; review naming rules if you need a refresher; remember that HONFIBrCl make diatomic molecules when they are not in a compoundnaming rules Step 3: States of matter are always written after the chemical formula Step 4: Balance the reaction

11/13/2010 How to translate a chemical reaction from words to symbols Step 1: It is helpful to circle or underline chemical formulas first Step 2: Translate chemical names to formulas; review naming rules if you need a refresher; remember that HONFIBrCl make diatomic molecules when they are not in a compoundnaming rules Step 3: States of matter are always written after the chemical formula Step 4: Balance the reaction Practice problem: Solid potassium chlorate, when heated, decomposes to produce liquid potassium chloride and oxygen gas. Step 1: Circle chemical formulas Step 2: Translate names to formulas Step 3: KClO 3 (s) → KCl(l) + O 2 (g) Step 4: 2KClO 3 (s) → 2KCl(l) + 3O 2 (g) KClO 3 KCl O 2 ∆ ∆