A 7.83 g sample of NaCl is dissolved in 90.00 mL of ethyl alcohol solution. Calculate the molar concentration of the solution.

mols NaCl = grams/molar mass

M NaCl = mols NaCl/0.090 L = ?

1.49 M

To calculate the molar concentration of the solution, we need to know the number of moles of NaCl and the volume of the solution.

First, we calculate the number of moles of NaCl:

Mass of NaCl = 7.83 g
Molar mass of NaCl = 58.44 g/mol

Number of moles of NaCl = Mass of NaCl / Molar mass of NaCl

Plugging in the values:
Number of moles of NaCl = 7.83 g / 58.44 g/mol ≈ 0.134 moles

Next, we calculate the volume of the solution in liters. The given volume is in milliliters, so we convert it to liters:

Volume of solution = 90.00 mL
Volume of solution in liters = 90.00 mL / 1000 mL/L = 0.090 L

Now that we have the number of moles of NaCl and the volume of the solution in liters, we can calculate the molar concentration.

Molar concentration (Molarity) = Number of moles / Volume (in liters)

Plugging in the values:
Molar concentration = 0.134 moles / 0.090 L ≈ 1.489 M

Thus, the molar concentration of the solution is approximately 1.489 M.