How many grams of KClO3 are needed to produce 50g of O2?

[Reema]

We had this question in the lecture .. but I couldn'nt copy the steps I was trying to understand but I dind'nt looool.

How many grams of KClO3 are required to produce 50 g of 02 from the following decomposition reaction?

2KClO3 ---> 2kClO3 + 3O2


the final answer is 127


I tried to work it out by myself by making a ratio


molar mass of 2KClO3 = 148.8 and for 3O2 = 48

grams of 02 = 3*50 = 150 grams
grams of of 2KClO3 = x


x\148 : 150\48

x=265


HELP!

 

[Borek]

You are doing strange things.

2KClO3 ---> 2kClO3 + 3O2

Huh? I guess it should be KCl on the right.

molar mass of 2KClO3 = 148.8 and for 3O2 = 48

What do you mean by "molar mass of 3O₂"? No such animal. There is a molar mass of O₂. It is not 48.

grams of 02 = 3*50 = 150 grams

No, 50 grams of O₂. This is a number given in the question.

I am not even going to try to understand your ratio, as numbers you put in it are already off.

Try these pages:

stoichiometric calculations in general

stoichiometric calculations using ratios