U7D3 Polyatomic Ions and GFM

U7D3: Polyatomic Ions and GFM HW: HW #3 Do Now: 1.HW out for check; LAB DUE 2. What is the charge on Pb in Pb 3 N 2 ? How do you know? Name it. What noble gas does the Nitrogen ion match? Today: Review/Quiz Forming and Naming Ionic Compounds w/Polyatomic ions GFM TTL

IX. POLYATOMIC IONS (PAI) A. Reference Table E Groups of atoms bond together by sharing electrons to form ions. one of the atoms in the group brings along a charge and group of atoms is not neutral “many atom” ion.

Complete this chart using reference table E. carbonate acetate sulfate chlorate hydroxide NO 3 - ClO 2 - CrO 4 -2 SO 3 -2 PO 4 -3

What type of charge do most of the PAI have? __________________ Most of these PAI end in _________ or __________ Two important exceptions are the positive ion _________ (ammonium) and the negative ion _________ (hydroxide). negative -ate -ite NH 4 + OH -

B. Writing and Naming Compounds with Polyatomic Ions Rules: The formula must be in lowest terms the charges must add up to zero. Parenthesis are used around the polyatomic ion when more than one of these ions is necessary in a formula: (NH 4 ) 2 O. To name compounds with polyatomic ions, use the name of the polyatomic ion listed on the reference table. Ex: (NH 4 ) 2 O is ammonium oxide; K 2 CO 3 is potassium carbonate. ternary ionic compounds: K 2 CO 3 and NaClO 4 binary ionic compounds: K 2 O and NaCl

Try your hand at these! KNO 3 Al(ClO 3 ) 3 SrSO 4 KNO 2 Mg 3 (PO 4 ) 2 Potassium nitrate Aluminum chlorate Strontium sulfate Potassium nitrite Magnesium phosphate

Going Backwards! ternary compounds Na +1 Ca +1 K +1 Au +3 NH 3 + OH - SO CrO CO ClO 4 - NaOH CaSO 4 K 2 CrO 4 Au 2 (CO 3 ) 3 NH 3 ClO 4

Ok…so how’re we doing so far? So.. Fist to Five Fist (not understanding need help) Five (feel I can teach it) Show me where you stand

Stoichiometry of Formulas Stoichiometry means math relationship, in this case chemical formulas.

A. The Smartie Molecule a)The smartie candy roll represents a molecule. The different colors represent different elements contained in the smartie molecule. List the colors contained in your molecule: _____________________________________ (This is Qualitative data-> type of elements)

Smartie Data b) Color and number present in your “molecule” in “ROYGBIVW” order. __________________________________________________ (This is Quantitative data-> type and number) c) Identify the following statements as examples of quantitative or qualitative data. ____The compound contains hydrogen and carbon atoms. ____The compound contains 8 hydrogen and 4 carbon atoms.

B. The MOLE a) Write the formula of your smartie molecule “ROYGBIV” (ex. R 3 O 4....) _______________ b) How many total “atoms” are present in ONE smartie molecule? _____________ c) Molecules are too small a unit to count => new unit mole = 6.02 x items one mole of molecules = 6.02 x molecules, etc. 1 mole of smartie molecules =____________ smartie molecules. 1 mole of atoms =6.02 x atoms1 mole of protons =6.02 x protons1 mole of Na +1 =6.02 x Na x

But… what of you have more than one mole????? Molteply!!!! 2 moles of smartie molecules = 2 x (6.02 x ) = 1.20 x molecules. Counting moles (1,2,3 etc) is so much easier than counting molecules (multiples of 6.02 x ) Since one smartie molecule contains ____“atoms”, We say that one mole of smartie molecules contain ______ moles of atoms. 15 Yuck!

d) Counting moles of atoms in a formula Determine the number of moles of each element and the total number of moles of atoms present in one mole of the compound ex.: KBr: 1 mole K & 1 mole Br ; total moles of atoms = 2 moles Li 2 O: 2 moles Li & 1 mole O ; total moles of atoms = 3 moles

What about parentheses? Multiply the number of each element inside the parenthesis by number on the outside the parenthesis: Sr(NO 3 ) 2 Sr:1 mole; N: 2x1= 2 moles; O: 3x2=6 moles total moles of atoms = 1 mole + 2 moles + 6 moles total moles of atoms = 9 moles

Complete the table 1 mole Na 1 mole Cl 1 mole Ca 2 moles Cl 2 moles K 1 mole S 4 moles O 1 mole Al 3 mole N 9 moles O 3 mole Mg 2 mole P 8 moles O 2 moles 3 moles 7 moles 13 moles

C. How do you measure moles? with a BALANCE!!!!! a. One mole of an element is equal to the atomic mass of that element in grams. gram formula mass (GFM).

GFM: Gram Formula Mass Look up the atomic mass of the element, round to the tenths place. unit: grams per mole (g/mole) Example: chlorine: Cl 35.5 g/mole. Remember: The unit for atomic mass on the PT for atoms is amu. For a mole…the unit is gram. Ex. The atomic mass of C is 12.0 amu so 1 mole of C will have a mass of 12.0 g. In other words 12.0 g/mole

Determine the gram formula mass of the elements given (Don’t forget the units): 1.0 g/ mole 63.5 g/ mole 79.9 g/ mole 14.0 g/ mole 40.1 g/ mole 55.8 g/ mole 24.3 g/ mole 32.1 g/ mole 16.0 g/ mole 27.0 g/ mole

b. Gram Formula Mass of Compounds GFM of a compound is the sum of the GFM of the elements of the atoms in the compound. KBr K = 39.1 g/mole; Br =79.9 g/mole GFM= ( )g/mole GFM =119.0 g/mole Li 2 O Li = 6.9 g/mole; O = 16.0 g/mole Since there are 2 Li, you must multiply the GFM of Li by 2: GFM = [2(6.9) ] GFM = 29.8 g/mole

Sr(NO 3 ) 2 Sr = 87.6 g/mole; N = 14.0 g/mole; O = 16.0 g/mole Again, you must multiply individual GFM by the number of each element present. GFM = [ (14.0) + 6(16.0)] g/mole GFM = g/mole.

Remember to show units & work! Units are g/ mole. NO Work NO CREDIT!!!! Na + Cl GFM= [ ] g/mol GFM = 58.5 g/mol Na + O +H GFM =[ ] g/mol GFM = 40.0 g/mol Al + 3 F GFM= [ (19.0)] g/mol GFM = 84.0 g/mol Zn + S + O GFM =[ ] g/mol GFM = g/mol

C. Special Formulas: Hydrates Hydrates are ionic compounds that have certain number of moles of water trapped in the crystal structure of 1 mole of the hydrate. Gypsum drywall used in the construction of homes is a hydrate of calcium sulfate. The trapped water in the drywall adds to the fire protection provided by walls constructed of drywall.

The formula of gypsum drywall is CaSO 4  2H 2 O. The ”  ” means it’s a hydrate; NOT multiply ! Two moles of water are trapped for every one mole of CaSO 4. So.. GFM of CaSO 4  2H 2 O GFM of CaSO x GFM of H 2 O GFM CaSO 4  2H 2 O = [ (16.0)]g/mole + 2 [2(1.0)+16.0] g/mole GFM = g/mole

What is the GFM of CoCl 2  6H 2 O ? GFM of CoCl 2  6H 2 O = GFM CoCl x GFM H 2 O Since the GFM of H 2 O is 18.0 g/mole, you can substitute that value in rather than calculate it each time. GFM = [ (35.5)] g/mole + 6 (18.0g/mole) GFM = g/mole Remember: Since there are 6 moles of water trapped in the CoCl 2  6H 2 O, the GFM of water is multiplied by 6.

Remember to show units & work! NO Work NO CREDIT!!!!

Ticket to leave 1. List a concept/skill that you mastered today. 1. List a topic/skill that you need to practice more 1. What do you still need help on?