Chemistry 101 PolyAtomic Ions – Flashcards
Unlock all answers in this set
Unlock answersquestion
| Oxanions Rule Number One |
answer
| Oxanions consist of oxygen and another element (the central element). The are names for the central element with the ending changed to "-ate" or "-ite". |
question
Rule number 2 for Oxanions
|
answer
| For two oxanions with the same central atom, the one with the "-ite" ending has one less oxygen than the one with the "-ate" ending. (This is the only difference between the two.) |
question
Rule Number 3 Oxanions
|
answer
| An oxanion with an "-ate" ending (and no prefix) will have three oxygen atoms if the central atom is in period 2 or is a halogen. All other oxanions ending in "-ate" have four oxygen atoms. |
question
Rule number 4 oxanions
|
answer
| Many of the halogens can have |
question
Rule #5 oxanions
|
answer
| Oxanions that have a charge of 2- or 3- can form new ions by adding hydrogen. The new ion is named by adding the word "hydrogen" in front of the anion name (for two hydrogen atoms, "dihydrogen" is used). Note that the charge decreases by one for each hydrogen present. |
question
Rule #6 oxanions
|
answer
| Dichromate (Cr2O72), permaganate (MnO4-), cyanate (OCN-), and hydroxide (OH-) are exceptions to these patterns. |
question
| What does the prefix "thio-" indicate? |
answer
| This prefix indicates that an oxygen atom has been replaced with a sulfur atom. For instance thiocynate (SCN-) is derived from (OCN-) Thiosulfate (S2O32-) is derived from sulfate (SO42-). Of the polyatomic ions needed to be known are cyanide (CN-), thiocynate (SCN-), and ammonium (NH4+). |
