What is the molality of a solution made by dissolving 5.2 g of NaCl in 100 g of water?

The molality is 0,89

Explanation:

A molal solution indicates the moles of solute in 1 kg of solvent (1000 g). First, we calculate the weight of 1 mol of NaCl:

Weight NaCl= Weight Na + Weight Cl=23g + 35,5 g=58,5 g/mol

58,5 g1 mol NaCl

5,2 gx=(5,2 gx1 mol NaCl)/58,5 g=0,089 mol NaCl

100g water0,089 mol NaCl

1000g waterx=(1000g waterx0,089 mol NaCl)/100 g water

x=0,89 mol NaCl> 0,89 m

c is the answer because when something is left after something evaporates that shows the chemical change.