Question

You have a 7 M solution of Na2O. If there are 500 mL, how many moles are present?

a. 0.25 moles
b. 1.75 moles
c. 3.5 moles
d. 7 moles

Answer 1

The number of moles of Na2O in a 7 M solution with a volume of 500 mL is 3.5 moles.

Step-by-step explanation:

To find the number of moles of Na2O in the solution, we need to know the volume of the solution and the molarity. Given that the solution has a molarity of 7 M and a volume of 500 mL, we can convert the volume to liters.

Volume solution = 500 mL = 0.500 L

Then, we can use the formula: Molarity (M) = Moles of solute / Volume of solution (L)

Substituting the values: 7 M = Moles of Na2O / 0.500 L

Rearranging the equation to solve for Moles of Na2O: Moles of Na2O = 7 M x 0.500 L = 3.5 moles