I am obsessed with such sentence structure as "S+V, N that +V".

It is said that "which" can refers back to preceeding sentence.
For example, I score high on the TOEFL test, which makes my mother happy.
I score hihg on the TOEFL test, making my mother happy.
Actually this setence structure is what I am familiar with, but recently I was told that to clarify the meaning of sentence it is better to use apposition that refers back preceding event.

Does the sentenc below I made to apply "S+V, N that +V" convey meaning clearly and grammatically?

"I complete term paper within five hours, the fact that shocks my classmate."

Thanks for teachers' instruction in advance.