Question

Urgent 25 points!!

Amanda was asked to make a solution of salt water using 32.0 grams of NaCl and 0.75 Liter of water. Amanda realized that first, she needed to find the number of moles there are in 32 grams of NaCl. She set up the following calculation to find the number of moles of NaCl.

32.0 g NaCl x 1 mole NaCl = 0.55 moles of NaCl

58.45 g NaCl

A. Did Amanda find the number of moles of NaCl correctly? If not, explain.

B. What does Amanda need to do next to calculate the molarity of the NaCl solution? Show your work for full credit.

Answer 1

A. Yes, Amanda find the number of moles of NaCl correctly.

B. 0.73 M.

Step-by-step explanation:

A. Did Amanda find the number of moles of NaCl correctly? If not, explain.

• Yes, Amanda find the number of moles of NaCl correctly.

• The relation to find the no. of moles of NaCl is:

No. of moles (n) of NaCl = mass/molar mass.

mass of NaCl = 32.0 g, molar mass of NaCl = 58.45 g/mol.

∴ No. of moles (n) of NaCl = mass/molar mass = (32.0 g)/(58.45 g/mol) = (32.0 g NaCl)*(1 mol of NaCl)/(58.45 g NaCl) = 0.547 mol ≅ 0.55 mol.

B. What does Amanda need to do next to calculate the molarity of the NaCl solution? Show your work for full credit.

• Molarity is the no. of moles of solute dissolved in a 1.0 liter of a solution.

∴ M = (no. of moles of NaCl)/(volume of solution (L)) = (0.55 mol)/(0.75 L) = 0.73 M.