The formula for Magnesium Nitride?

I know the formula for Magnesium nitride is Mg_3N_2 but why? On my test I put Mg(NO)_2 which was wrong. The charge for MG is 2+ and N is 3- and isn't nitiride NO2? I'm confused..

I suck at chemistry..

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  • John
    Lv 7
    7 years ago
    Favorite Answer

    NO₂ is a polyatomic ion called a nitrite. It's 'brother', NO₃, is called nitrate. When writing the formula for compounds when the name is given, check out the ending of the 'second name'. If the compound's name ends in -'ide', it's probably a binary compound (one containing only two kinds of elements). There are exceptions to this like a compound containing the hydroxide (OH⁻) polyatomic ion. The name of most polyatomic ions formed with a non-metal combined with oxygen end in -ite, or -ate. Examples, in addition to the nitrite and nitrate are: carbonate (CO₃) hydrogen carbonate, HCO₃, sulfite (SO₃), sulfate (SO₄).

    Magnesium nitride is Mg₂N₃. The -ide ending tells us its binary and therefore contains only Mg⁺² and N⁻³. Balancing the charges requires 3 Mg's and 2 N's.

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  • rippey
    Lv 4
    3 years ago

    Magnesium Nitride

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  • Anonymous
    7 years ago

    NO2 is nitrite (not nitride) which has a single negative charge. so magnesium nitrite will be Mg(NO2)2

    with NO2 (-1) the O has a 4- charge but the N actually has a 3+ oxidation state totaling 1-

    nitride ion stands for N (3-) ion so magnesium nitride is Mg3N2

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  • 7 years ago

    Nitride is N3-

    Nitrite is NO2-

    Nitrate is NO3-

    Magnesium ion is Mg2+

    Mg2+ has valency II

    N3- has valency III

    Therefore Mg3N2

    Source(s): Other guy is wrong with NO2
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  • 7 years ago

    NO2- is nitrate...so basically what u'd written was Magnesium nitrate.

    N3- is a nitride.

    since Magnesium forms an Mg2+ ion and nitrogen an N3-,

    3Mg + 2N -----> Mg3N2

    Source(s): self
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