ما هو المقدار الذي يجب التصدق به من المال المكتسب من شراء وبيع هاتف مسروق وما نتج عنه من بيوعات أخرى؟

It is not permissible to buy stolen goods, knowing that they are stolen. Whoever does so is sinful, a partner to the thief in his sin. If you know the owner of the stolen phone that you bought and sold, then you are obligated to return the phone to its owner if possible. Otherwise, return a similar item or its value. If you do not know the owner of the phone, then give its value in charity on his behalf. As for what you sold the phone for and what resulted from that, it is yours. You are only required to return the value of the phone or a similar item to its owner.