Hey there! Sign in to join this conversationNew here? Join for free
x Turn on thread page Beta
 You are Here: Home

# Enthalpy change question? watch

1. The standard enthalpy changes of formation of iron(II) oxide, FeO(s), and aluminium oxide,
Al2O3(s), are –266 kJ mol–1 and –1676 kJ mol–1
respectively.

What is the enthalpy change under standard conditions for the following reaction?
3FeO(s) + 2Al (s) 3Fe(s) + Al 2O3(s)?

Please Explain!
2. you need to construct a Hess diagram. Put your elements at the bottom and your reaction at the top. Now one arrow up from the elements to the reactants and another arrow up to the products.

Now, see how many times you have to multiply your delta Hf to generate the right number of molecules of reactants and products. Reverse the direction of the left hand arrow (the one to the reactants) and therefore the sign of delta H.

Now simply add your delta H values and hey presto!

(blimey, never had to explain a Hess cycle in words before!)
3. (Original post by Ash_94)
The standard enthalpy changes of formation of iron(II) oxide, FeO(s), and aluminium oxide,
Al2O3(s), are –266 kJ mol–1 and –1676 kJ mol–1
respectively.

What is the enthalpy change under standard conditions for the following reaction?
3FeO(s) + 2Al (s) 3Fe(s) + Al 2O3(s)?

Please Explain!
so did you manage this? Here is a sketch that might help you visualise it.
Attached Images

Reply
Submit reply
Turn on thread page Beta
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: March 27, 2011
Today on TSR

### How much will your degree earn you?

Find out where yours ranks...

### I do my boyfriend's uni assignments

Poll

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.