Aim # 3: How can we determine the formula of a molecular compound from its name? H.W. # 3 Study pp. 94-100 Ans. ques. p. 108 # 10,11 p. 111 # 49 Do Now: Name the following compounds Cu(NO3)2 NH4Br Pb(SO4)3 Hg2(NO3)2 Write formulas for the following compounds zinc nitrate sodium sulfate hydrogen sulfide ammonium thiocyanate potassium permanganate

I Naming binary molecular compounds (Type III binary compounds) Prefixes are used to indicate the number of atoms of each element in the molecule. mon(o) - 1 hex(a) - 6 di - 2 hept(a)- 7 tri - 3 oct(a) - 8 tetr(a) - 4 non(a) - 9 pent(a) - 5 dec(a) - 10 e.g. dinitrogen trioxide N2O3

Now you try it. dinitrogen monoxide tetraphosphorous hexoxide dinitrogen pentasulfide dihydrogen monoxide

carbon tetrachloride CCl4 Now you try it. phosphorous trichloride Note: for the first element in the compound, the prefix “mon(o)” is not used- we simply use the name of the element. e.g. sulfur dioxide SO2 carbon tetrachloride CCl4 Now you try it. phosphorous trichloride carbon disulfide oxygen diflouride

II Writing names from formulas WORK BACKWARDS! Don’t forget- the last element ends in “ide”. Name the following compounds: PCl5 S4N2 OF2 SeO2 N2S3

Review: What is the correct formula for ammonium carbonate? 1) NH4(CO3)2 3) (NH4)2(CO3)2 2) NH4CO3 4) (NH4)2CO3 2. What is the total number of atoms in one molecule of (NH4)2SO4? 1) 10 2) 11 3) 14 4) 15

4. Which formula is correctly paired with its name? 3. Which formula is an empirical formula? 1) K2O 2) H2O2 3) C2H6 4) C6H6 4. Which formula is correctly paired with its name? 1) MgCl2 - magnesium chlorine 2) K2O - phosphorous dioxide 3) CuCl2 - copper (II) chloride 4) FeO - iron (IV) oxide

5. Elements fro groups 15 and 16 will combine to form a compound with the general formula 1) M2N3 2) MN2 3) M2N3 4) M2N