Calculate the molarity of the two solutions. The second solution contains 21.3 g of NaCl in 825 mL of solution.

Answer 1

Howdy Allison!

I have broken the question down into steps so you can use this as a guide on how to approach these types of problems:

1. What unit does our answer need to be (where are we going)?
2. Molarity(M)= moles/L
3. What were we given (where are we starting)?
4. 21.3 g of NaCl in 825 mL solution
5. How do we get there?
6. grams to moles
7. Add the atomic weight of both Na (22.99) and Cl (35.453) = 58.44g NaCl /mol

21.3 g NaCl X 1 mol

58.44g NaCl

= 0.364 moles

b. mol to mol/L (M)

ii. mL to L

0.364 moles = 0.442 M or 442 mM

0.825 L