How to determine the prefix, suffix

How can I tell when to use ate ite or ide prefix when naming a compund insted of using the formula. I read the about rules but it is still confusing.


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Give us an example of a formula when this confuses you, so we can help explain the features that give it away. At some point, sometimes you simply need to memorize them.

The suffix -ide is used of monatomic negative ions such as Cl (NaCl sodium chlorIDE), O (CaO calcium oxide), N (BN boron nitride); the prefixes mon(o)- di- tri- tetra- pent(a)- hex(a)- and hept(a)- refer respectively to single (carbon monoxide CO), double (carbon disulfide CS2), triple (nitrogen triiodide NI3), four (osmium tetroxide OsO4), five, six, and seven negative ions in a compound. The prefix sesqui- is used for half ratios, ie C2O3 carbon sesquioxide.

The suffixes ite and -ate refer to complex, usually oxygen bearing ions. -ate is the usual form, thus NaCO3 9sodium carbonate; where two valences exist -ate is the higher and -ite is the lower Rb2SO4 rubidium sulfate versus Rb2SO3 rubidium sulfite; if a hydrogen atom is attached to the negative ion the prefix bi- is used Mg(HCO3)2 magnesium bicarbonate, though some prefer CsHSO4 cesium hydrogen sulfate to cesium bisulfate; if there are more than two valences, the highest is given the prefix per as KMnO4 potassium permanganate but K2MnO4 potassium manganate, KMnO2 potassium manganite; the lowest valence employs the prefix hypo- though sub was formerly used.

There are a number of other terms an anion with an extra sulfur atom takes the prefix thio, one with a transition metal plus oxygen has the suffix -yl as in vanadyl or uranyl; there are books giving the specific rules.

yes, and if it helps you to remember

"-ite" refers to a SMALL oxidation level / valancy,

and MITES are very small things....

WebElements: the periodic table on the WWW []

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