Question

Which of the following statements is true of an aqueous solution of sodium chloride? A]One that has 30.0 grams of NaCl dissolved in 100 grams of water is more concentrated than one that has 15.0 grams of NaCl dissolved in 100 grams of water. B]One that has 30.0 grams of NaCl dissolved in 100 grams of water is more dilute than one that has 15.0 grams of NaCl dissolved in 100 grams of water. C[One that has 30.0 grams of NaCl dissolved in 100 grams of water would have the same molarity as one that has 15.0 grams of NaCl dissolved in 100 grams of water. D]One that has 30.0 grams of NaCl dissolved in 100 grams of water has less solute than one that has 15.0 grams of NaCl dissolved in 100 grams of water.

Answer 1

One that has 30.0 grams of NaCl dissolved in 100 grams of water is more concentrated than one that has 15.0 grams of NaCl dissolved in 100 grams of water. A is the correct answer.

Answer 2

Answer: Option (A) is the correct answer.

Explanation:

When 30 g of NaCl is dissolven in 100 g of water then it means NaCl is the solute and water is the solvent.

More is the amount of solute present in a solution more concentrated the solution will be.

For example, an aqueous solution with 30.0 grams of NaCl dissolved in 100 grams of water is more concentrated than one that has 15.0 grams of NaCl dissolved in 100 grams of water.

Whereas molarity is the number of moles present in a liter of solution.

Also,    Molarity = $\frac{mass}{\text{molar mass} \times Volume}$

As molar mass of NaCl is 58.44 g/mol. Therefore, assuming volume as 1 L then molarity of a solution containing 30 g of NaCl is as follows.

        Molarity = $\frac{mass}{\text{molar mass} \times Volume}$

                       = $\frac{30 g}{58.44 g/mol \times 1 L}$

                       = 0.513 M

Whereas molarity of a solution containing 15 g of NaCl is as follows.

           Molarity = $\frac{mass}{\text{molar mass} \times Volume}$

                       = $\frac{15 g}{58.44 g/mol \times 1 L}$

                       = 0.256 M

This shows that molarity of both the solutions is not the same.

Thus, we can conclude that the statement one that has 30.0 grams of NaCl dissolved in 100 grams of water is more concentrated than one that has 15.0 grams of NaCl dissolved in 100 grams of water, is true of an aqueous solution of sodium chloride.