Answer:
4.92 grams of sodium phosphate (Na₃PO₄) are required to make 125 milliliters of a 0.240 M.
Explanation:
Molarity is a measure of concentration that indicates the number of moles of solute that are dissolved in a given volume.
The molarity of a solution is calculated by dividing the moles of the solute by the volume of the solution:
Molarity is expressed in units
.
In this case:
- Molarity= 0.240 M
- number of moles= ?
- volume= 125 mL= 0.125 L
Replacing in the definition of molarity:

Solving:
number of moles= 0.240 M*0.125 L
number of moles= 0.03 moles
Being the molar mass of sodium phosphate 164 g/mole, that is, the mass of one mole of the compound, you can calculate the mass of 0.03 moles using the following rule of three: if 1 mole of the compound has 164 grams, 0.03 moles contains how much mass?

mass= 4.92 grams
<u><em>4.92 grams of sodium phosphate (Na₃PO₄) are required to make 125 milliliters of a 0.240 M.</em></u>