Give the general formula for any dialkene; that is, a straight-chain hydrocarbon with two double bonds along the chain. (Type your answer using the format CnHn+1 for CnHn+1.)
I know just alkene would be CnH2n but im not sure how to make it with the dialkene.
can any1 help me?
thanks!!
draw some
cH3-cH2-cH=cH-cH=cH2
note on the ends, there are 3H
one each double bond, each C has one less H (each side)
CnH(2+2n-4) check that above n=6, byt this formula C6H10 counting... 6c, 10H
now the check
CH2=CH-CH2-CH=CH2
formula: C5H8
count: C5H8
CnH(2n-2) Try that.
oh. that wasn't the correct answer
Try some. The general formula for a dialkene is the same as the general formula for an alkyne isn't it. CnH2n-2.
I wrote about six or 7 straight chain hydrocarbons, stuck a couple double bonds in each, added H atoms to make up the quadrivalent C each, and voila! All of them worked with CnH2n-2.
i tried the answer in my online hw and it said it was wrong. i am looking in my text book and CnH2n-2. the answer you guys are saying is the formula for alkynes.
but i need to find the formula for dialkene.
the formula for just alkene is CnH2n. but i don't know how to make that into the di part of dialkene
Certainly! To determine the general formula for a dialkene, which is a straight-chain hydrocarbon with two double bonds along the chain, we'll start with the general formula for an alkene. As you mentioned, the general formula for an alkene is CnH2n.
To account for the presence of two double bonds, we need to add two additional hydrogens to the formula. Keep in mind that each double bond consumes two hydrogens since it replaces two single bonds. Therefore, for a dialkene, we'll have two fewer hydrogens in the formula compared to the corresponding alkene.
So, to find the general formula for a dialkene, we can modify the alkene formula CnH2n by subtracting two from the number of hydrogens. This gives us the general formula CnH(2n-2) for any dialkene.
Therefore, the general formula for any dialkene, a straight-chain hydrocarbon with two double bonds along the chain, is CnH(2n-2).