Hey Everybody–

 Here is a minor distinction between two reactions that I have lately seen some students get crossed up on. 

Cold KMnO4, when reacted with a double bond, give the diol.

Hot KMnO4, when reacted with a double bond, cleaves the double bond to give two carboxylic acids. 

Temperature is the key here, don’t lose points on this.

 For more information on this, please go to organic chemistry

Good luck and happy reacting.