Question

A 7.00 g sample of NaCl was dissolved in enough water to give 250 mL solution.

What is the molarity of the solution?

Answer 1

To calculate the molarity of the NaCl solution, convert the mass of NaCl to moles using its molar mass, then divide by the volume of the solution in liters to get a solution with a molarity of 0.479 M.

Step-by-step explanation:

Molarity Calculation of a NaCl Solution

To calculate the molarity of a solution, you need to know the number of moles of the solute (in this case, sodium chloride or NaCl) and the volume of the solution in liters. The formula for molarity (M) is:

M = moles of solute / volume of solution in liters

First, we need to convert the mass of NaCl to moles using the molar mass of NaCl, which is approximately 58.44 g/mol:

moles NaCl = mass (g) / molar mass (g/mol)

moles NaCl = 7.00 g / 58.44 g/mol = 0.1198 moles

Next, we convert the volume of the solution to liters:

250 mL = 0.250 L

Now we can calculate the molarity:

M = 0.1198 moles / 0.250 L

M = 0.479 M

Therefore, the molarity of the solution is 0.479 M.

Answer 2

Answer: The molarity of given solution is 0.476 M.

Step-by-step explanation:

Given : mass of sample (solute) = 7.0 g

Volume of solution (solvent) = 250 mL

Convert mL into L as follows.

`1 mL = 0.001 L\\ 250 mL = 250 mL * (0.001 L)/(1 mL)\\= 0.25 L`

Molar mass of NaCl is 58.44 g/mol. Hence, moles of NaCl are calculated as follows.

`No. of moles = (mass)/(molar mass)\\= (7.00 g)/(58.44 g/mol)\\= 0.119 mol`

Molarity is the number of moles of a substance present in one liter of solution or solvent.

So, molarity of given solution is calculated as follows.

`Molarity = (no. of moles)/(Volume (in L))\\= (0.119 mol)/(0.25 L)\\= 0.476 M`

Thus, we can conclude that molarity of given solution is 0.476 M.