How do you write a balanced chemical equation for silver acetate and potassium iodide becoming potassium nitrate and lead iodide?

1 Answer

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udonbutterfly | Student, College Freshman | (Level 1) Valedictorian

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First let's put the words into a reaction:

Silver Acetate + Potassium iodide => potassium nitrate + lead iodide

Now, lets write out these compounds:

AgC2H3O2 + KI => KNO3 + PbI2 ( Now it's easier to see that it is virtually impossible for this to even be a reaction so since you cannot get Ag from Pb. Therefore you can't balance this equation).

So to help you understand, I'll give you a similar example.

Cu + AgNO3 => Cu(NO3)2 + Ag

Now let's analyze how many of each we have on the left side

Ag - 1

NO3(for the most part treat big ions like this, No3, SO4, ClO4,etc, as if they are one element) -1

Cu- 1

Now the products side

Cu- 1

NO3- 2

Ag- 1

Compare both sides. Now do you see how there are 2 NO3s on the products side? To balance the equation I would have to have 2 NO3s on the reaction side. Therefore I would add a 2 in front of the Ag. So the equation should look something like this:

Cu + 2AgNO3 => Cu(NO3)2 + Ag

Now do you notice something different? By adding the 2 in front of AgNO3 I also increased the number of Ag, so I now need to add a 2 in front of the Ag on the products side in order to completely balance the equation. The final equation should be:

Cu + 2AgNO3 => Cu(NO3)2 + 2Ag

Compare and make sure each side has the same number of elements.