The salt dissolves in the water and the sand will gather at the bottom.
We know that 1 mole of anything has a volume of 22.4 liters.
And 1 mole of N2 gas has a weight of 28 grams.
Comparing them , we get the answer as 5.31
The objects may exchange heat between each other if they are in contact with each other.
The two objects will allow flow of heat between them if they have a difference in temperature from each other.
The heat will flow from higher temperature object to lower temperature object. The will reach a final temperature (common to each other) and then there will be no heat transfer between each other.
