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Naming ionic compounds: part II. How to name compounds that contain transition metals. Using Roman numerals to denote the charge of the transition metal. FeO. Fe 2 O 3. Why do we need a roman numeral? . Some metals can take MORE THAN ONE charge
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Naming ionic compounds: part II How to name compounds that contain transition metals
Using Roman numerals to denote the charge of the transition metal FeO Fe2O3
Why do we need a roman numeral? • Some metals can take MORE THAN ONE charge • The roman numeral always indicates the charge on the metal in that compound • The roman numeral does NOT tell you the number of metal atoms present in the compound.
Let’s have another try at this… WS2 WS3
You try some on your ownPause the video and answer these questions. When you have answered them, restart the video. What is the name of CuCl2 What is the name of PbS2
You try some on your ownPause the video and answer these questions. When you have answered them, restart the video. What is the name of CuCl2 What is the name of PbS2 Here is what we initially know about the charges Cu? Cl-1 Here is what we initially know about the charges Pb? S-2 Since there are two Cl- ions, Cu needs to be in its Cu+2 oxidation state to balance out the negative. Since there are two S-2 ions, Pb needs to be in its Pb+4 oxidation state to balance out the negative. Copper (II) chloride Lead (IV) sulfide
Turning the process around What is the formula for copper (I) phosphide? What is the formula for tin (II) fluoride?
A side note: The mercury (I) cation What is different about the mercury (I) ion? What is the formula for mercury (I) iodide?
You try some on your ownPause the video and answer these questions. When you have answered them, restart the video. What is the formula for iron (III) sulfide What is the formula for mercury (II) chloride?
You try some on your ownPause the video and answer these questions. When you have answered them, restart the video. What is the formula for iron (III) sulfide What is the formula for mercury (II) chloride? Here is what we initially know about the charges Fe3+ S2- Here is what we initially know about the charges Hg2+ Cl- Since the LCM for a 3 & 2 is 6, we will need two Fe3+ ions and three S2- ions to balance out the charges You will need two Cl- ions to balance out the +2 charge on the mercury. Fe2S3 HgCl2