than expected / expectation

[yamamoto]

Hello.
In this sentence ' We knew the weather was going to be warm but it is actually hotter than expected.' can I replace the last word 'expected' with expectation?

[bhaisahab]

Hello.
In this sentence ' We knew the weather was going to be warm but it is actually hotter than expected.' can I replace the last word 'expected' with expectation?

No.

[yamamoto]

Thanks for the reply.

If I can't use the phrase 'than expectation' in the sentence questioned, how about this sentence?

Writing an essay needs longer time than expectation.

Is this also incorrect?

Could you possibly expain it in detail to me?

[bhaisahab]

Thanks for the reply.

If I can't use the phrase 'than expectation' in the sentence questioned, how about this sentence?

Writing an essay needs longer time than expectation.

Is this also incorrect?

Could you possibly expain it in detail to me?

Yes, it's incorrect too. "expectation" is a noun, you need "expected", an adjective.