My father passed away before my grandfather. Am I entitled to any share of my grandfather`s inheritance?
                                All perfect praise be to Allah the Lord of the Worlds. May His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
According to Islamic courts, you are entitled to what is called obligatory bequest (The distribution of estate to grandchildren who has either lost a parent before the death of the grandparents). Therefore, if your grandfather left such bequest for you, then take that share or else it is more prudent to take nothing. And Allah The Almighty Knows Best. 
                             
                        
                            
                                
                                Who has the right to child custody when final divorce takes place?
                                The wife has the right to child custody until her children reach the age of puberty. However, if she gets married, the right of custody becomes that of her mother`s.
                             
                        
                            
                                
                                Is the patient who is on dialysis twice a week obliged to observe fasting? Is his fasting on the days he is on dialysis considered valid or not?
                                Praise be to Allah the Lord of the Worlds.
Dialysis invalidates fasting because of the nutritional fluid used in that procedure, as pointed by specialized doctors, in addition to causing bodies to enter the stomach. Therefore, it is recommended that the patient who had undergone dialysis to observe fasting for the rest of that day, if he is able to, and make up for it after Ramadan. However, if the doctor told him that fasting, at any time, would damage his health, then he must break his fast and pay a ransom against every missed day. We pray that Allah blesses this person with recovery. And Allah The Almighty Knows Best.
                             
                        
                            
                                
                                Is washing the private part after urinating (Istinjaa`) a condition, and is it done with water and soap, or with water only?
                                Istinjaa` is obligatory for removing impurity, and it can be done with toilet paper, or a stone, or water. It is preferable to do Istinjaa` first with paper, or stone, or the like, then to wash the private part with water until making sure that the impurity has been removed. Using soap is not a condition, but there is no harm in doing so provided that it is washed off with water. It is also permissible to use either water, or paper if impurity is removed by any.