Write the overall balanced equation for the operation of the catalytic converter described by the four elementary steps:

Question

anonymous · Answer

Assume the catalyst is palladium. 
CO (g)  → CO (ad) (repeated x2)
NO (g) → N(ad) + O (ad)
N (ad) + NO (g) → N2(g) + O(ad)
CO (ad) + O (ad) → CO2(g) (repeated x2)

I know how to write an overall equation, but am confused by the adsorption (ad) and repeated steps... Can someone help me please?

aaronq · Answer

you may need to write coefficients for the 1st and 4th steps, since they're repeated

like so,  $2CO_{(g)}  → 2CO_{(ad)}$

anonymous · Answer

When I work it out, I get:
$$2NO _{g} \rightarrow N_{2(g)} + 2O_{(ad)}$$
Does that sound right?

aaronq · Answer

i think you're missing some stuff, like $CO_{(g)}$ you should have some in there

anonymous · Answer

$$2CO_{(g)} + 2NO_{(g)} \rightarrow N_{2(g)} + 2CO_{2(g)}$$

I cancelled out the wrong CO, how about now?

aaronq · Answer

it looks much better

anonymous · Answer

Thank you for your help! :)

aaronq · Answer

no problem at all !