what is the word "it" in the question referring to?

[Kwfine]

Hi,
I was helping my friend Jane cooking the lunch this afternoon.
In the meanwhile, she asked me:
"How long does it take to cook the 2kg chicken for lunch?"
"I don't know actually", I simply replied.

But then I was thinking why the word "it" is needed in the question that Jane had asked. What is it referring to? Is it referring to Time or anything else?
If it is referring to time, then how about this one:
"How much time is needed to cook the 2kg chicken for lunch?"
Is this correct?
_________________
各位前輩安安, 我是kitty喔!

[Stalin]

Hi,

Both are correct.

[Kwfine]

So, any difference in meaning if I change the sentence to future tense like this:
"How long will it take to cook the 2kg chicken for lunch?"

where the origianl sentence is:
"How long does it take to cook the 2kg chicken for lunch?"
_________________
各位前輩安安, 我是kitty喔!

[Dansk]

Exactly the same meaning! :)

'it' doesn't refer to anything in particular, if you need an answer to fill this void I suppose it could refer to time! :D

[Kwfine]