Which is more concentrated, a solution (1) prepared by dissolving 21.0 g of naf (0.500 mol) in enough water to make 500 ml of solution or a solution (2) prepared by dissolving 10.5 g (0.250 mol) of naf in enough water to make 100 ml of solution?

Answer:

A solution (2) prepared by dissolving 10.5 g (0.250 mol) of naf in enough water to make 100 ml of solution is more concentrated.

Explanation:

Calculate the molarity of Solution 1

                      M = (moles)× 1000/ V (ml)

                      M =  (0.500) × 1000/500 = 1 M

Calculate the molarity of Solution 2

                     M = (moles)× 1000/ V (ml)

                     M =  (0.250) × 1000/100 = 2.5 M

Result:

As the molarity of Solution two is greater than solution 1. so Solution 2 is more concentrated

Answer:

A solution (2) prepared by dissolving 10.5 g (0.250 mol) of naf in enough water to make 100 ml of solution is more concentrated.

Explanation:

Calculate the molarity of Solution 1

                      M = (moles)× 1000/ V (ml)

                      M =  (0.500) × 1000/500 = 1 M

Calculate the molarity of Solution 2

                     M = (moles)× 1000/ V (ml)

                     M =  (0.250) × 1000/100 = 2.5 M

Result:

As the molarity of Solution two is greater than solution 1. so Solution 2 is more concentrated

Sorry i dont understand the question can you rephase it?

The correct answer is "hydrogen".