Question

Need help explaining.. To write out a balance chemical reaction for a combustion, will it always include O2 in the reactant? For example, coal. Would I write it out as
C + O2 -> CO2?? And how would I know how many moles of each to write out?

Answer 1

yeah. you can't burn anything without oxygen. moles? like in terms of the coefficients?

Answer 2

yes. the coefficients. thank you for responding! :)

Answer 3

you always wanna use the lowest numbers possible so if the reaction is balanced you don't need to include more numbers.

Answer 4

ohh i see. so let's say i write the reaction for ethanol... would i start like this? C2H5OH + O2 ?

Answer 5

yes, your products would be CO2 and H2O (assuming complete combustion, in real life you get some CO as well).

Answer 6

how do you know what the product will look like? i'm horrible at stoichiometry, i think that's what it's called

Answer 7

we'll for combustion reactions it's always the same thing \(CO_2+H_2O\). For other types of reactions it's different, of course. Have you gone through the 5 categories? (single-, double displacement, etc.)

Answer 8

i don't believe i have. categories of what?

Answer 9

of types of reactions. I'm sure you have by now.

Answer 10

do you learn all of that in general chemistry also?

Answer 11

yeah, it's one of the first things you learn after drawing lewis and bohr diagrams. They're single displacement, double displacement, decomposition, synthesis and acid-base, does that ring a bell?

Answer 12

acid-base and maybe decomposition does sound familiar, not the others though. unless the book did go through it but i just didn't understand it.

Answer 13

hm thats possible, they're usually presented all together. If you need a refresher you should look it up on youtube there are tons of great videos. Ask here after if you need clarification on any of them.

Answer 14

awesome. Thank you! :)

Answer 15

no problem, good luck !