Can I take the ram from my new computer and put it into my old one?

My Acer broke, and I want to put the ram from it into my old HP Pavilion


Acer: http://www.crucial.com/store/listparts.aspx?model=Aspire%205315
HP: http://www.crucial.com/store/listparts.aspx?model=Pavilion%20zx5000%20Series

Please explain why it will or will not work