Question

2. An aqueous solution contains 132.8 g of NaCl dissolved in enough water to make 1.000 x 10³ mL of solution.

What is the molar concentration of NaCl?
2.272 M
0.1531 M
2.006 M
2.620 M
0.1328 M

Answer 1

1 mol L−1

Step-by-step explanation:

:In order to find the molarity of the solution, you must determine the number of moles of solute present in exactly1 L=103 mLof solution. Notice that you already know the number of milligrams of sodium chloride, the solute, present in 4 mL of solution, so start by calculating the mass of solute present in 103 mL of solution.103mL solution⋅240 mg NaCl4mL solution=60⋅103 mgSince1 g=103.mgyou can say that 103 mL of solution contain60⋅103.mg=60.gof sodium chloride. Now, to convert this to moles, use the molar mass of the compound60g⋅1 mole NaCl58.44g=1.027 moles NaClSince this represents the number of moles of sodium chloride present in 103 mL of solution, you can say that the molarity of the solution is equal tomolarity = 1 mol L−1−−−−−−−−−−−−−−−−−−−The answer must be rounded to one significant figure, the number of sig figs you have for the volume of the solution.

Answer 2

Molar concentration of NaCl is 2.272 M

Step-by-step explanation:

Molar concentration (also known as molarity) is calculated by dividing the moles of solute by the volume of the solution in liters.

First, let's calculate the moles of NaCl:

`\sf Moles = (Mass )/(Molar\: Mass)`

The molar mass of NaCl (sodium chloride) is approximately 58.44 g/mol.

`\sf Moles \:of \:NaCl =( 132.8 g )/(58.44 g/mol )\approx 2.272 moles`

Now, let's convert the volume of the solution to liters:

`\sf 1.000 * 10^3\: mL = 1.000 L`

Now we can calculate the molar concentration (molarity):

`\sf Molarity (M) =\frac{ \textsf{Moles of Solute }}{\textsf{ Volume of Solution (in liters) }}`

`\sf Molarity = (2.272 moles )/( 1.000 L )\approx 2.272 M`

So, the molar concentration of NaCl in the solution is approximately 2.272 M.