You want to prepare 0.5 L (500mL) of a 0.250M Na2SO4 solution. How many grams of do you need to measure out for the solution? [MW of Na2SO4 = 142 g
How many mols do you want? That's M x L = mols = ?
How many grams is that? That's g = mols x molar mass = ?
To find out how many grams of Na2SO4 you need to measure out for the solution, you can use the following steps:
1. Determine the molar mass of Na2SO4:
The molecular weight (MW) of Na2SO4 is given as 142 g/mol.
2. Convert the volume of the solution from liters to milliliters:
0.5 L is equivalent to 500 mL.
3. Calculate the amount of Na2SO4 in moles:
Use the formula: moles = Molarity × volume (in liters).
moles = 0.250 M × 0.5 L = 0.125 moles
4. Convert moles to grams:
Multiply the number of moles by the molar mass of Na2SO4.
grams = moles × MW
grams = 0.125 moles × 142 g/mol = 17.75 grams
Therefore, you need to measure out approximately 17.75 grams of Na2SO4 for the 0.5 L (500 mL) 0.250M Na2SO4 solution.