Question

If this reaction produced 32.5 g of KCl, how much O2 was produced (in grams)?

Answer 1

When heated, KClO3 decomposes into KCl and O2.

Answer 2

What have you tried so far to solve the problem?

Answer 3

converted g to moles of KCl. Got stuck after that. Not solid on converting moles of KCl to moles of O2

Answer 4

@surry99

Answer 5

ok in chemistry you should always start with a balanced chemical rxn...so do that for me please

Answer 6

Hint: KCl03----> KCl + 02
Now you need to balance this equation

Answer 7

2KClO3 ----> 2KCl + 3O2

Answer 8

Good...now for every 2 moles of KCl produced, how many moles of O2 were produced?

Answer 9

3?

Answer 10

Yes,,,so how many moles of KCl do you have?

Answer 11

2

Answer 12

no... 32.5 g of KCl was produced...how many moles is that?

Answer 13

32.5g x 1 mol KCl/74.54g KCl= 0.436 mol KCl ?

Answer 14

ok...so now how many moles of 02 were produced.

Answer 15

This is where I get confused. I use 0.436 mol KCl but idk what goes next. I know I need g on top & moles on bottom but I'm not sure which way to set it up

Answer 16

Ah...just write in the units and you will get it correct...

.436 mol of KCl * 3 moles of O2/2 moles of KCl = ?

What happens to the units of moles of KCl when you multiply?

Answer 17

They cancel out, which gives you 0.654 mol O2

Answer 18

but i still need to find g... so I use molar mass?

Answer 19

Exactly use the molar mass of O2

Excellent....always write in your units and that way you can check to see if the mole ration is correct!!

Answer 20

Ok. You help out a lot. Thank you so much.

Answer 21

your welcome.