Sajda-e-Sahw

Q: What should we recite in sajda e sahw?

Q: If someone is performing zohar farz salah and in the last rakat after tashahud (attahiyat), he stands and after completing the sajda if the 5th rakat, he remembers that he made the mistake in this condition. What should he do and how should he complete his farz salah?

Q: If a person left out a portion of tashahud (At-Tahiyyat) in Salaah, does he have to make Sajdah-e-Sahw? 

Q: If due to some disturbance, a person missed an Aayah in Surah ​Faatihah, does he have to make Sajdah-e-Sahw? 

Q: Sometimes, I lose focus during Salaah for over 10 seconds wherein I remain silent and do not recite qiraat. When this happens, I silently think about worldly matters. I don’t do this on purpose. It just happens and takes a while for me to realize that I should focus on Salaah. Does this invalidate the Salaah?

Q: I made a mistake in one of the prayers but forgot to do sajdah sahw and got up. Later I remembered and then repeated the prayer. Should I perform sajdah sahw in the repeated prayer? 

Q: If I completed my salah and forgot to do sajda sahw, how to do it after salah? After salam if I sit and recite attahiyaat and say salam on the right side and do two sajdah and say salam to both sides. Is it the correct way? 

Q: If a muqtadi performs sajda-e-sahw without turning his head to the right and saying salaam, will the salaah be valid or should he repeat it?

Q: Say I recite the whole of Surah Alaq in one rakaah of salah, after performing the sajda tilawah of the last verse and getting up, do I recite the whole of the next surah al-qadr or just the first ayah?

Q: When sajda-e-sahw is to be done, the procedure is that it will be performed in the last qa'dah, i.e. after tashahhud, one salam to right and then 2 sujood. Sometimes due to carelessness I recite part of durood after tashahhud and then realize that I have to do sajda-e-sahw then what should I do at that moment? Should I proceed to sajda-e-sahw at that moment?