How many grams of sodium chloride do you need to prepare 250 mL of a 5.00%(w/v) sodium chloride solution
5% NaCl w/v means 5 g NaCl/100 mL soln.
So for 250 mL soln you will need
5g x (250/100) = ??
You can look at it another way.
(grams/mL)*100 = %
(X/250)*100 = 5
Solve for X.
To determine the number of grams of sodium chloride needed to prepare a 5.00% (w/v) sodium chloride solution, we can use the following formula:
Mass of solute = Volume of solution (in mL) × Concentration of solute (in g/mL)
Given:
Volume of solution (V) = 250 mL
Concentration of solute (%) = 5.00% (w/v)
1. Convert the volume of the solution from milliliters (mL) to liters (L):
V = 250 mL = 250/1000 L = 0.250 L
2. Calculate the concentration of solute in grams per milliliter (g/mL):
Concentration (in g/mL) = 5.00% = 5.00 g/100 mL = 0.0500 g/mL
3. Calculate the mass of solute (sodium chloride) needed:
Mass of solute = V × Concentration
Mass of solute = 0.250 L × 0.0500 g/mL = 0.0125 g
Therefore, you would need 0.0125 grams of sodium chloride to prepare 250 mL of a 5.00% (w/v) sodium chloride solution.