Anonymous asked in Science & MathematicsChemistry · 6 years ago

How do you Balance equations? (Chemistry)?

Okay so I know how to do problems like __H2 + __Cl2 --> __HCl

it would be _1_H2+_1_Cl2 --> _2_HCl

because h = 2 and Cl = 2 so you multiply H by 2 and Cl by 2

soooo they are equal right? I get those questions but

how do I do questions like this?

__Na + __Cl2 --> __NaCl


__K + __MgBr2 --> __KBr + __Mg

this is not my homework, I was absent from class so I need to catch up, thanks for help.

1 Answer

  • Lexi R
    Lv 7
    6 years ago
    Favorite Answer

    __Na + __Cl2 --> __NaCl

    The Na is already balanced, so look at the Cl, you have 2 Cl on the LHS and only 1 Cl on the right hand side. Put a 2 in front of NaCl. (remember, you can only put numbers in front of compounds to balance an equation)

    __Na + __Cl2 --> _2_NaCl

    but, this throws out the Na. Now we need to re-balance it by putting a 2 in front of Na on the LHS

    _2_Na + __Cl2 --> _2_NaCl


    __K + __MgBr2 --> __KBr + __Mg

    K and Mg are balanced initially, but Br is not, put a 2 in front of the KBr to balance the Br

    __K + __MgBr2 --> _2_KBr + __Mg

    but now K is unbalanced, put a 2 in front of the K

    _2_K + __MgBr2 --> _2_KBr + __Mg


    Also, handy tip..... as a general rule leave Hydrogen (H2) and Oxygen (O2) and water (H2O until last in equations that have these molecules. Do all the other atoms first.

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