2.4A Restricted rotation and the double bond 121 Fig. The structure and bond angles of ethene Rotation Rotate90° H Fig 2.9 Rotation of a carbon atom of a double bond through an angle of 90 results in the breaking of the t bond2.4A Restricted rotation and the double bond H H H H 121 118 0 0 Fig. The structure and bond angles of ethene H H H H H H H H Rotation Rotate 90 0 Fig 2.9 Rotation of a carbon atom of a double bond through an angle of 90 results in the breaking of the  bond 0