Re: 回复: Re: 回复: Re: chem help!!!!!!1 please
thanks * hundred times*tommykins said:You can't do it if excess wasn't there.
Be assured that they'll never give you a question where there isn't excess though.
For example - you should know about combustion right? In complete combustion between a hydrocarbon and oxygen the products are only water and CO2. However, this only takes place if there is excess of O2, if there wasn't an excess then the products would be CO and C along with CO2, we're unable to guess how much of each is produced, thus we can't really do any calculations.