Question

Potassium nitrate decomposes on heating, producing potassium oxide and gaseous nitrogen and oxygen:
4KNO3(s)--> 2K2O(s) + 2N2(g) + 5O2(g)
To produce 56.6 kg of oxygen, how many (a) moles of KNO3 must be heated? (b) Grams of KNO3 must must heated?

Answer 1

I worked this same problem a day or so ago. Frankly, I don't think the equation is correct.

Answer 2

Convert 63.7 kg of oxygen to grams. Then use stoichiometry and convert the grams of Oxygen to moles of Oxygen, then moles of KNO3 using the equation.

Calculations: 63.7 kg ---> 63,700 g. Divide by 32 grams of O2, then multiply by (4 moles KNO3/5 moles O2).

For the second part, take your answer from part A, and multiply it by 101.11 grams/mol of KNO3.