Moles in chemistry

[BishoyGamil]

I have a doubt in calculations in chemistry.
Do i round (approximate) the results? if yes to what decimal place? or to 0 decimal places?.
I that results insidde the question shouldnt be roundded e.g If it asks about mass and i calculated it contaimns 0.0024 moles i mustnt approximate or else i will end up wiyth a very inaccurate result but what about the final answer?? Thanks in advance. :

 

[CaptainDanger]

Always write the moles in 3 s.f figures... So for how many decimal places it depends on the value.... And use it to find the mass...

 

[BishoyGamil]

Thank you what aboutr masses?
3 significant figures as well?

 

[CaptainDanger]

If its too small then write in 3 s.f other wise round it off to suitable number...

 

[charlatan77]

If it is an exact number i.e. 0.00065 mol , put it down

Never round if it can be written down. If you get some weird screwed up number i.e. 6.342342034303, then you must have made a mistake and should check calculation.

Sometimes note that you could write numbers as a fraction, i.e 64.33333333333334 = 64 1/3 mol

 

[CaptainDanger]

Yes in case of exact number don't round it off...