3)How many grams of sodium chloride do you need to weigh out to prepare 1.4L of 0.9% NaCL solution?
0.9% NaCl by what? w/w, w/v?
To determine the number of grams of sodium chloride needed to prepare the solution, we'll first find the mass of the solution and then calculate the mass of sodium chloride required.
Step 1: Calculate the mass of the solution.
To calculate the mass of the solution, we need to consider the volume and density of the solution. However, since the density is not given, we will assume that the density of the solution is equal to the density of water, which is approximately 1 gram per milliliter (g/mL).
Given:
Volume of solution (V) = 1.4 L
Since 1 L = 1000 mL, we can convert the volume to milliliters:
V = 1.4 L × 1000 mL/L
V = 1400 mL
Using the density assumption of 1 g/mL and the formula:
Mass (m) = Volume (V) × Density (d)
Mass of solution (m) = 1400 mL × 1 g/mL
Mass of solution (m) = 1400 g
Step 2: Calculate the mass of sodium chloride.
The percentage concentration of the solution (0.9%) represents 0.9 grams of sodium chloride per 100 mL of solution.
Given:
Percentage concentration (C) = 0.9%
Mass of solution (m) = 1400 g
Using the formula:
Mass of solute (s) = (Mass of solution (m) × Percentage concentration (C))/100
Mass of sodium chloride (s) = (1400 g × 0.9%)/100
Mass of sodium chloride (s) = 12.6 g
To prepare a 0.9% NaCl solution with a volume of 1.4 L, you would need to weigh out 12.6 grams of sodium chloride.