Why do we ignore noble gases usually when we discuss electronegativity values?

A48 g piece of ice at 0.0 ∘c is added to a sample of water at 7.4 ∘c. all of the ice melts and the temperature of the water decreases to 0.0 ∘c. how many grams of water were in the sample?

The answer for #3 is c but i don't know why

The diagram below shows a cell placed in a solution.a cell is shown placed inside a beaker. it is labeled cell. the solution inside the beaker is labeled 40% salt solution and the solution inside the cell is labeled 20% salt solution.only water is allowed to move in and out of the cell. what will most likely happen to the cell? it will expand as water moves out of it. it will shrink as water moves out of it.it will expand as water moves into it. it will shrink as water moves into it.