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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: id1oteque on October 15, 2019, 03:40:03 PM

Title: Writing chemical reactions
Post by: id1oteque on October 15, 2019, 03:40:03 PM

When writing a redox reaction, how do you know what element/compound to put as the product? Also, does it matter which reactant is written first on the left side of the formula?

Examples:

2AgNO3+Cu--->Cu(NO3)2+2Ag    (why copper nitrate instead of silver)

or

2Al+ 3CuCl2---> 3Cu + 2AlCl3   (why copper instead of aluminum chloride)

or

Mg+2HCl--->MgCl2+H2

Any help is appreciated!

Title: Re: Writing chemical reactions
Post by: AWK on October 15, 2019, 04:17:27 PM

For now, you are working with single exchange reactions that are the simplest and you already have great troubles. In this case, just check the redox potentials.
https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Supplemental_Modules_(Analytical_Chemistry)/Electrochemistry/Redox_Potentials/Standard_Potentials
On this basis (based on the position in the table or the numerical values ​​of the radicals) you are able to approximate whether the reaction is spontaneous.

The order of the reagents on the left or right side of the equation is arbitrary.