Ashu, a 15 year old boy while travelling in car saw that a factory near the outskirt of city caught fire. He came to know from his father that the factory is of petrochemicals. Quickly, he told his father to stop the car. He got down and called the fire brigade. Fortunately, fire brigade arrived within 15 minutes and controlled the fire. (i) What is the substance used as fire extinguisher by firemen and why? (ii) What is the basic principal of controlling the fire? (iii) Which value of Ashu is depicted here?

For cyclohexane compounds drawn in a chair conformation:   -axial bonds are vertical  -equatorial bonds are parallel to two bonds within the ring.  thus, as i assume the chair conformation is drawn:   -the x group is in an axial position, as are the five other vertical bonds.  -three axial bonds are on the top face of the ring  -the other three axial bonds are on the bottom face  the position of the second substituent on each ring carbon is equatorial.  gauche groups must be on an adjacent carbon such as carbon 6 and carbon 2, and also gauche groups are rotated by 60 degrees relative to each other.  drawing the newman projections for c1–c2 and c1–c6 aids in visualizing the groups that are gauche to the y group on c1.  click this link and watch some academic videos that may you more understand the topic 

They are all full and don't need any more electrons in there outer shell.

A.(nh4)(2co3)is the correct answer