please help GCSE chemistry

ammonia reacts with oxygen in the presence of a metal oxide catalyst to produce nitrogen and water.
which metal oxide is most likely to be a catalyst for this reaction?
a) CaO
b) Cr2O3
c)MgO
d)Na2O
the answer is b but I don't understand why

Reply 1

bl0bf1sh

have a think about the metals involved in the compounds
what type of elements are often used as catalysts?

Reply 2

butter fly

Original post by bl0bf1sh

have a think about the metals involved in the compounds
what type of elements are often used as catalysts?

never mind i get why now thanks :smile:

Reply 3

crochetnbooks

please could you explain why

Reply 4

SagaciousSag

Original post by crochetnbooks

please could you explain why

Look at the groups the metals are in. That should give you the answer.

Reply 5

scimus63

transition metals act as catalysts

Reply 6

Elliezhou

Original post by butter fly

never mind i get why now thanks :smile:

Could you please tell me why too?

Reply 7

bl0bf1sh

Original post by Elliezhou

Could you please tell me why too?

Transition metals, and transition metal compounds, are often good catalysts.

chemguide has a nice page about transition metals – scroll down a bit and there's a section on catalytic activity:
https://www.chemguide.co.uk/inorganic/transition/features.html

And on catalysts in general:
https://www.chemguide.co.uk/physical/catalysismenu.html
https://www.chemguide.co.uk/physical/catalysis/introduction.html
You'll see that many of the examples of catalysts used are transition metals :smile:

Spoiler

Reply 8

no0ooo

Original post by bl0bf1sh