• Does passing wind, from the anus without a smell, invalidate prayer?
If a person is certain of having passed wind even if it was with no smell, then both his/her ablution and prayer are invalidated, thus he/she should remake ablution and re-perform prayer .
• Is Zakah due on the orphan`s money?
Yes, Zakah is due on the money of the orphan.
• Is washing both openings(Istinjaa`) a must before every ablution?
Washing the front and back openings(Istinjaa`) is a must in case they have an impurity, but if they do not, there is no need for that, and Istinjaa` is not a condition for the validity of ablution.
• Is it permissible to make ablution without answering the call of nature after waking up?
Washing front and back openings(Istinjaa`) is not a condition for the validity of ablution because it is done to remove Najaasah(impurity), thus if there is no Najaasah, there is no need for that, and then it is permissible to make ablution without answering the call of nature. However, prayer is invalidated if there is Najaasah on the anus ,or the front opening, so it(Najaasah) must be removed for the prayer to become valid, and not the ablution.