Question

What is the concentration (M) of a NaCl solution prepared by dissolving 9.3 g of NaCl in sufficient
water to give 350 mL of solution?

Answer 1

Answer:

Molarity = 0.458M

Explanation:

Molarity is the representation of the solution.

Molarity:  

it is amount of solute in moles per litre of solution and represented by M

Formula used for Molarity

                      M = moles of solute / Litre of solution

Data Given:

NaCl = 9.3 g

volume of solution = 350 mL

volume of solution in litre = 350/1000

volume of solution = 0.35 L

Molarity = ?

Formula used to Calculate M

                      M = moles of NaCl / Litre of solution . . . . . . . . .  (1)

So

we have to first calculate moles of NaCl

                 Moles of NaCl = mass of NaCl/ Molar Mass (NaCl) . . . . . . .  (2)

*Molar Mass of NaCl = 58 g/mol

Put values in Eq (2)

                  Moles of NaCl = 9.3 g/ 58 g/mol

                  Moles of NaCl = 0.16 mol

Now

Put values in Eq (1)

                       M =  0.16 mol / 0.35 L

                       M = 0.458

So the Molarity = 0.458M

Answer 2

Taking into account the definition of molarity, the concentration (M) of the NaCl solution is 0.45 $\frac{moles}{liter}$.

It is necessary to know that molarity reflects the concentration of a solution, indicating the number of moles of solute that appear dissolved in a given volume. In other words, molarity is the amount of a substance in a certain volume of solution.

Molarity is also known as the molar concentration of a solution.

The molarity of a solution is calculated by dividing the moles of the solute by the volume of the solution:

$molarity=\frac{number of moles of solute}{volume}$

Molarity is expressed in units $\frac{moles}{liter}$.

In this case, molar mass is the mass of one mole of a substance. Then, the molar mass of NaCl being 58.45 $\frac{g}{mole}$, the number of moles representing 9.3 g of NaCl is calculated as:

$amount of moles=\frac{9.3 g}{58.45 \frac{g}{mole}}$

amount of moles= 0.159 moles

On the other side, the volume of the solution is 350 mL= 0.350 L (being 1000 mL=1 L)

Replacing in the definition of molarity:

$molarity=\frac{0.159 moles}{0.350 L}$

Solving:

molarity= 0.45 $\frac{moles}{liter}$

Finally, the concentration (M) of the NaCl solution is 0.45 $\frac{moles}{liter}$.

Learn more about molarity with this example: brainly.com/question/15406534?referrer=searchResults