No, it isn’t. Careful users of the language would prefer the use of “hanged” rather than “hung”. The word “hung” is usually used with objects and not with human beings.
Here are a few examples. *Sarita hung her new coat on the doorknob. *The outlaw who had killed 12 people was hanged at noon.
Will be /would be
Secondly, in your example, you should say, “will be hanged” rather than “would be hanged”. The use of “would” suggests that the event may not take place. For example, if you say, “I would help you”, it implies that you want to help me, but for some reason you are not in a position to. “I would help you if I could. But I can’t”. The use of “would” suggests a condition. “I would marry you,” for example, implies that you would consider marrying the person if certain other conditions were met — perhaps if he/she had more money, or had been more handsome/beautiful! These conditions are not going to be met; therefore, you are not going to marry the person! Your sentence should be “The convict will be hanged tomorrow.”