Last and final question: Consider the reaction 2KNO3 + 10K ---> 6K2O + N2. If 155 grams of K reacted with 122 grams of KNO3, what is the limiting reagent?

a) KNO3
b) K
c) Neither
d) not enough information

I would think it's d? Because it doesn't ask to know either the maximum amount of K2O or N2? So, therefore, can't solve.

1 answer

a. figure moles of K (155/24 about 6
b. figure moles of KNO3 (122/101=1.22)

you need a ratio 1moleKNO3 to 5 molesK

So I did the math in my head, which is not accurate enough for this q. So work those out accurately and look at the ratio you get. If you get more than 5:1, then you have to little KNO3, if you have less than 5:1, you have to little K.