Just wonderingg
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I dont understand when to put -ide or -ate and the end of a ion/ionic compound.

In my revision guide it says -ate is used where the negatively charged ionic compound contains 3 or more elements and one of which is oxygen,but then sulfate only contains 2 elements and ends in -ate
Helpp???
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emma64
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Normally it’s -ate when there is oxygen involved: so4 (sulfate) co3 (carbonate). I’ve never heard any rules about the number of different elements involved?

-ide is normally for when a halide ion (group 7) is involved: kcl ( potassium chloride) CuI (copper iodide) or most other ions without oxygen (sulphide) (nitride)

Don’t worry after a while it comes naturally and you won’t even think about it
Last edited by emma64; 5 months ago
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Deggs_14
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I wouldn’t worry about prefixes too much, at GCSE you should find that
“-ide” is when an atom becomes an ion due to a loss or gain of electrons. Eg a chlorine atom, a chloride ion, oxygen atom, oxide ion. (negative ions / anions)
“-ate” denotes a polyatomic ion containing oxygen. The amount of oxygens depends on the oxidation state of the central element or its coordination number, but that can change. You can have chlorate (I) ClO-, where chlorine has an oxidation state of +1, and chlorate (V), ClO3- where chlorine has an oxidation state of +5.

Sulphate (VI) is SO4 2-, and Sulphate (IV) or Sulphite, is SO3 2-.
GCSE revision guides aren’t very contextual, and simplify things too much. At this level, -ide is for just a negative ion from an atom like bromine to bromide, carbon to carbide, nitrogen to nitride etc, and -ate refers to a polyatomic ion with oxygen. Eg Nitride ion is N3-, and Nitrate (V) ion is NO3-, or carbide to carbonate etc.
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Deggs_14
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(Original post by emma64)
Normally it’s -ate when there is oxygen involved: so4 (sulfate) co3 (carbonate). I’ve never heard any rules about the number of different elements involved?

-ide is normally for when a halide ion (group 7) is involved: kcl ( potassium chloride) CuI (copper iodide) or most other ions without oxygen (sulphide) (nitride)

Don’t worry after a while it comes naturally and you won’t even think about it
No “ide” is not just for halide ions. Zinc Selenide is ZnS or Tungsten Carbide is WC which are not halide ions. You should change it to refer to generally atoms which have become ions from the element itself.

Cyanide ion is CN-, and Cyanate is OCN-, and Thiocyanate is SCN-
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emma64
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(Original post by Deggs_14)
No “ide” is not just for halide ions. Zinc Selenide is ZnS or Tungsten Carbide is WC which are not halogen ions. You should change it to refer to generally atoms which have become ions from the element itself.

Of course with chemistry there are lots of exceptions, like Cyanide is CN-, and Cyanate is OCN-
Yeah I know, that why I didn’t say just halide ions. Granted I didn’t explain it perfectly
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Deggs_14
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TLDR,
“-ide” for anions formed from the element due to reduction. Oxygen to Oxide, Nitrogen to Nitride, Bromine to Bromide.
“-ate” for polyatomic ions with oxygen. Carbonate is (CO3 2-), Phosphate is (PO4 3-), Nitrate is (NO3 -) (sufficient for GCSE level). The number of oxygen atoms depends on the compound, but you’ll find “-ate” anions at GCSE.
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Just wonderingg
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(Original post by emma64)
Normally it’s -ate when there is oxygen involved: so4 (sulfate) co3 (carbonate). I’ve never heard any rules about the number of different elements involved?

-ide is normally for when a halide ion (group 7) is involved: kcl ( potassium chloride) CuI (copper iodide) or most other ions without oxygen (sulphide) (nitride)

Don’t worry after a while it comes naturally and you won’t even think about it
Thank you!!!
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Just wonderingg
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(Original post by Deggs_14)
I wouldn’t worry about prefixes too much, at GCSE you should find that
“-ide” is when an atom becomes an ion due to a loss or gain of electrons. Eg a chlorine atom, a chloride ion, oxygen atom, oxide ion. (negative ions / anions)
“-ate” denotes a polyatomic ion containing oxygen. The amount of oxygens depends on the oxidation state of the central element or its coordination number, but that can change. You can have chlorate (I) ClO-, where chlorine has an oxidation state of +1, and chlorate (V), ClO3- where chlorine has an oxidation state of +5.

Sulphate (VI) is SO4 2-, and Sulphate (IV) or Sulphite, is SO3 2-.
GCSE revision guides aren’t very contextual, and simplify things too much. At this level, -ide is for just a negative ion from an atom like bromine to bromide, carbon to carbide, nitrogen to nitride etc, and -ate refers to a polyatomic ion with oxygen. Eg Nitride ion is N3-, and Nitrate (V) ion is NO3-, or carbide to carbonate etc.
Thank you so much!!
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Deggs_14
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(Original post by Just wonderingg)
Thank you so much!!
Sorry I meant suffixes*
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Pigster
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(Original post by Just wonderingg)
In my revision guide it says -ate is used where the negatively charged ionic compound contains 3 or more elements and one of which is oxygen,but then sulfate only contains 2 elements and ends in -ate
There is no such thing as 'sulfate'.

You can have (for example) calcium sulfate, but never just sulfate on its own. Calcium sulfate "contains 3 or more elements and one of which is oxygen".

The sulfate ion is not a compound. Ionic compounds must have both negative (e.g. sulfate, SO42-) and positive ions (e.g. calcium, Ca2+).
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