Chemistry · Chapter 20

Alkenes and Alkynes

Four carbons, one bond you control. Make it single, double or triple and watch the shape, the formula and the name change. Then run a reaction and compare how much of your starting mass lands in the product.

The molecule gold numbers follow the IUPAC count

The four-carbon molecule you set up

A single bond spins freely, so the two ends swap places all day long.

What you have

butane saturated
Formula
C4H10
Molar mass (g/mol)
58.12
Bond length (pm)
154
Angle at those carbons
109.5°
Degrees of unsaturation
0
Rotation
free

Set the bond

Which bond
How many bonds
Geometry only a double bond between C2 and C3 has two forms

React it

Pick a reagent
Nothing has reacted yet
A double or triple bond can take a reagent straight across it. A single bond cannot, so an alkane has to swap an atom out instead.