moles don't make sense! (1 Viewer)

[Thowra]

Two hydrogen molecules plus one oxygen molecule goes to two water molecules. Yes, I understand that bit, but somehow, two hydrogen moles plus one oxygen mole gets two water moles. What the hell??? Where did the other mole go? There are three moles on the left hand side of the equation, but two one the right hand side! What happened to the other mole? Please help!

 

[minijumbuk]

Well, think of it this way:This means that 2 moles of H2 and 1 mole of O2 react to form 2 moles of H2O
The ratio simply shows the relative amount of reactants you need in order to form the product.

Hmm, think of it this way:

You have a 5 cent coin and a 50 cent coin with glue. The 5 cent coin can be element A, and 50 cent coin can be element B. You glue them together (bonds created), now you have 1 coin of value 55 cents.

Your question is: When I glue my 5 cents and 50 cents together, why shouldn't I get two lots of 55 cent coins? I have 2 coins to begin with!

Do you see the flaw?

 

[aussiechick007]

^ good explanation

 

[minijumbuk]

 

[A High Way Man]

mole ratios != moles

 

[Thowra]

Well, think of it this way:This means that 2 moles of H2 and 1 mole of O2 react to form 2 moles of H2O
The ratio simply shows the relative amount of reactants you need in order to form the product.

Hmm, think of it this way:

You have a 5 cent coin and a 50 cent coin with glue. The 5 cent coin can be element A, and 50 cent coin can be element B. You glue them together (bonds created), now you have 1 coin of value 55 cents.

Your question is: When I glue my 5 cents and 50 cents together, why shouldn't I get two lots of 55 cent coins? I have 2 coins to begin with!

Do you see the flaw?

makes more sense now...thanks

 

[lolokay]

Two hydrogen molecules plus one oxygen molecule goes to two water molecules. Yes, I understand that bit, but somehow, two hydrogen moles plus one oxygen mole gets two water moles. What the hell??? Where did the other mole go? There are three moles on the left hand side of the equation, but two one the right hand side! What happened to the other mole? Please help!

It sounds as though you don't understand what a mole is; it is a particular number of elementary units (atoms, molecules, formula units) - approx. 6.02*10^23 of them (the number of C.12 atoms in 12g of C.12)

so saying 2mol H2 + 1mol O2 = 2mol H2O is equivalent to saying
2x molecules of H2 + 1x molecules of O2 = 2x molecules of H2O
where x =~ 6.02*10^23 (no. molecules in a mole)