Tuesday
October 21, 2014

Homework Help: Chemistry

Posted by A Canadian on Wednesday, February 6, 2013 at 4:39pm.

This isn't exactly a homework question, I'm just trying to understand the concept we learned today...
So say we had:
4Fe + 3O2 → 2Fe2O3 + 1.65 x 10^3 kJ

Does that mean for every 4 mol of Fe, 3 mol of O2, and 2 mol of Fe2O3 we have 1.65 x 10^3 kJ?

And if I were to calculate what the enthalpy change for the formation of 23.6 g of iron(iii) oxide was,
Would it be 23.6g Fe2O3 or 23.6g of 2Fe2O3 that I would use in the equation...? When do you account for the fact that there's 2 moles of Fe2O3?

My confused attempt at solving:

Enthalpy=23.6g Fe2O3 x 1 mol Fe2O3/[(2x56) + (3x16)]g x -1.65x10^3 kJ/1 mol Fe2O3
= -243.38 kJ

Yeah, I'm pretty confused; can someone please clear things up for me??

Also, I guess it's not that important but how come when doing 1mol of Fe2O3/molar mass of Fe2O3 you can just do 1mol/160g instead of 1mol/160g/mol?? Because for molar mass we always use the unit g/mol...

Thanks so much in advance !! It's only the second lesson in grade 12 chemistry and I'm already lost! Not good.. :(

Answer this Question

First Name:
School Subject:
Answer:

Related Questions

chem - 4Fe(s) + 3O2(g) → 2Fe2O3(s) Identify the type of chemical reaction ...
Chemistry -  4Fe + 3O2 -> 2Fe2O3 + 1.65E3 kJ  C) what is the enthalpy change ...
Chemistry - 4Fe + 3O2 -> 2Fe2O3 + 1.65E3 kJ C) what is the enthalpy change ...
chemistry - Can some one please balance this equation for me Fe + O2---> ...
Chemistry - I am really struggling with this equation question...can someone ...
chemistry - how many grams of Fe2O3 are formed when 16.7g of Fe reacts ...
Chemistry - Using the equation 4Fe + 3O2 -> 2Fe2O3, calculae the total mass ...
chemistry - How many grams of O2 are needed to produce 45.8 grams of Fe2O3 in ...
Chemistry-Stoichiometry - what is the limiting reactant if 0.10 moles Fe and 0....
chemistry - the rusting of iron is represented by the eqquation 4Fe + 3O2 -->...

Search
Members