By increasing the length of heat exchanger, how the outlet temperature of both cold and hot stream changes?
a- hot stream temperature increases and cold stream temperature decreases
b- cold stream temperature increases and hot stream temperature decreases
c- both cold stream and hot stream temperature increases

You know how the first one if filled up like the objects do the same but with the other categories

The law of conservation of mass states that a mass of an object or the amount of matter composed inside an object or thing will not change unless it is added or removed of the matter that is contained in the object itself.

Answer isno products will be formedyou need the required activation energy/good geometry  to be able to get a reaction going. (without favorable  geometry, more energy would be needed.)this is because molecules in a reaction have electrons surrounding them. as molecules approach one another, they start to slow down because of the like charge repulsion (electrons have a negative charge—like charges repel). the appropriate amount of energy is needed to overcome that mutual repulsion. without that amount of energy, the speed of the molecules will be slowed down to such an extent  they do not even collide; they end up rebounding from each other.

Ithink it will be b. crude oil hopefully this you