It's just a simple proportion question, isn't it? So you set it up:
I21 / K1 = I22 / K2
In this case, I21 is your 9.74 g of iodine molecules, K1 is your 3g and K2 is your 10 g of potassium, and I22 is your unknown amount of I2.
Multiply both sides by K2 to isolate I22. Then you can add this value of I2 to the 10g of K to get the value for the KI produced.
You could also set it up the way you've started, with K and KI, and use the same type of trick, but then you have to subtract in order to get the amount/mass of I2, instead of adding to get the amount of KI. *shrug*
Err, wow. You make it seem so simple, I feel stupid now.
Yeah, I see that now. Kind of like riding a bike, you just suddenly get the hang of it. I found that you need to take the units you have, then multiply those by the ones you want to end up with, but not necessarily the amount, then divide the result by the bottom starting units. Then it got harder with the Mole mass units, but that was just a matter of conversion.
I guess I got messed up because instead of changing the actual units of mass, it was units of chemicals. O.o? Thanks a lot for you help, I really appreciate it! You saved my sorry butt.
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I21 / K1 = I22 / K2
In this case, I21 is your 9.74 g of iodine molecules, K1 is your 3g and K2 is your 10 g of potassium, and I22 is your unknown amount of I2.
Multiply both sides by K2 to isolate I22. Then you can add this value of I2 to the 10g of K to get the value for the KI produced.
You could also set it up the way you've started, with K and KI, and use the same type of trick, but then you have to subtract in order to get the amount/mass of I2, instead of adding to get the amount of KI. *shrug*
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Yeah, I see that now. Kind of like riding a bike, you just suddenly get the hang of it.
I found that you need to take the units you have, then multiply those by the ones you want to end up with, but not necessarily the amount, then divide the result by the bottom starting units. Then it got harder with the Mole mass units, but that was just a matter of conversion.
I guess I got messed up because instead of changing the actual units of mass, it was units of chemicals. O.o? Thanks a lot for you help, I really appreciate it! You saved my sorry butt.
Reply
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