Most Helpful Guy
My advice would be to not do it. He is your ex, he is not your boyfriend or your responsibility anymore. I know that doesn't mean that you stop caring automatically and I appreciate that you are trying to be kind. However, he already has more than enough emotions to deal with right now and he doesn't need more emotional confusion coming into it. Now is not the time to reach out, he needs time to deal with his grief.
Most Helpful Girl
Make sure your motives are strictly about his loss of his Mother. And if they are, and you reach out to him, keep it strictly about being sorry for his loss, and let it be. Please remember, if it was a bad break up- he may have many mixed feelings, and at this time in his life, he just lost probably the most (or one of the most) important people in his life. I am not being mean, don't know your situation, but you could add additional trauma to an already heartbreaking situation. I am not being mean, just make sure to RESPECT him. sometimes we all want to do things, and don't think about the other person so much! I know you are trying to be kind, just tread lightly, Best of Luck