Question? (1 Viewer)

[ordnaiv]

This is just a quick question from the conquering chemistry textbook Exercise 12:

Cooling systems in motor cars are sealed: this means that the liquid(mainly water) is reciculated and is only occasionally replaced. A typical cooling system contains 10L. If all the liquid was water containing 9ppm dissolved oxygen, how much iron of the engine block would one filling of the system oxidise?

how would one go about in answering the question...is it complicated or am I just missing the point?

thanks.

 

[brenton1987]

10 L of water with 9 ppm of O2
= 9*10^-5 L O2

Vol = n * 22.4
9*10-5 = n * 22.4
n = 4.0178*10^-6 mol O2

Oxidation of Iron = 4Fe + 3O2 --> 2Fe2O3
where 3O2 = 4.0178*10^-6 mol

Moles of Fe = 4.0178*10^-6 / 3 * 4
= 5.357*10^-6 mol
= 2.9918*10^-4 g

* Convert ppm to L
* Convert L to mol
* Solve stoichiometry

 

[ordnaiv]

thanks