Questions

12 N in a C means 12 Numbers in a Clock. 

India's most consistent middle-order batsman Cheteshwar Pujara stormed his way into record books after playing a marathon innings against Australia on fourth day of the third Test match
surpassing Rahul Dravid previous best of 495 balls. 

Sodium hydroxide - NaOH is caustic soda

Sodium carbonate - Na2CO3 is washing soda

Sodium bicarbonate - NaHCO3  is baking soda 

Because of high stability, large Q (Quality Factor) & the frequency that doesn't drift with aging. Crystal is used as a clock source most of the times.

A hard real-time system guarantees that critical tasks complete on time. This goal requires that all delays in the system be bounded from the retrieval of the stored data to the time that it takes the operating system to finish any request made of it. A soft real time system where a critical real-time task gets priority over other tasks and retains that priority until it completes. As in hard real time systems kernel delays need to be bounded