How to determine the molarity of a 1.8% NaCl solution.
You need the density.
1.8% NaCl (by mass or w/w) means 1.8 g NaCl/100 g solution.
1.8g NaCl/molar mass NaCl = moles NaCl.
Then 100 g solution converted to mL from the density. volume = 100 g/density and convert mL to L.
M = moles/L.
To determine the molarity of a NaCl solution, you need to know the mass of NaCl in grams and the volume of the solution in liters.
Step 1: Convert the given percentage NaCl to grams.
If the solution is labeled as 1.8% NaCl, it means there are 1.8 grams of NaCl in 100 grams of the solution. So, to find the mass of NaCl, we need to assume a certain amount of the solution (e.g., 100 grams).
Mass of NaCl = (1.8 grams / 100 grams) x 100 grams = 1.8 grams.
Step 2: Determine the molar mass of NaCl.
The molar mass of NaCl is the sum of the atomic masses of sodium (Na) and chlorine (Cl) atoms. The atomic masses of Na and Cl are 22.99 g/mol and 35.45 g/mol, respectively.
Molar mass of NaCl = 22.99 g/mol + 35.45 g/mol = 58.44 g/mol.
Step 3: Convert the mass of NaCl to moles.
Using the molar mass of NaCl, we can convert the mass of NaCl from step 1 to moles.
Moles of NaCl = Mass of NaCl / Molar mass of NaCl
= 1.8 grams / 58.44 g/mol
= 0.0308 moles.
Step 4: Determine the volume of the solution in liters.
To find the molarity, we need to know the volume of the solution in liters. If the volume is not given specifically, you can assume 1 liter.
Volume of solution = 1 liter.
Step 5: Calculate the molarity of the NaCl solution.
Now we have the moles of NaCl from step 3 and the volume of the solution from step 4. We can calculate the molarity using the formula:
Molarity (M) = Moles of solute / Volume of solution in liters
= 0.0308 moles / 1 liter
= 0.0308 M.
Therefore, the molarity of the 1.8% NaCl solution is 0.0308 M.
To determine the molarity of a solution, you will need to know the concentration of the solute (in moles) and the volume of the solution (in liters). In this case, you have a 1.8% NaCl solution, which means that there is 1.8 grams of NaCl for every 100 mL of solution.
To start, convert the given percent concentration (1.8%) into grams per liter (g/L) by using the following steps:
1. Assume you have 100 mL of the solution. Convert it to liters by dividing by 1000:
100 mL ÷ 1000 = 0.1 L
2. Calculate the mass of NaCl in 0.1 L of the solution using the given percent concentration:
1.8% of 0.1 L = 0.018 L
3. Convert the mass from milliliters (g/mL) to grams (g):
0.018 L * 1 g/mL = 0.018 grams
Now that you have the mass of NaCl (0.018 grams) and the volume of the solution (0.1 liters), you can calculate the molarity using the formula:
Molarity (M) = Moles of solute / Volume of solution (in liters)
To find the moles of NaCl:
1. Calculate the molar mass of NaCl (sodium chloride) by adding the atomic masses of sodium (Na) and chlorine (Cl) from the periodic table.
Molar mass of Na = 22.99 g/mol
Molar mass of Cl = 35.45 g/mol
Molar mass of NaCl = 22.99 g/mol + 35.45 g/mol = 58.44 g/mol
2. Convert the grams of NaCl into moles by dividing the mass by the molar mass:
Moles of NaCl = 0.018 g / 58.44 g/mol ≈ 0.0003086 moles
Finally, substitute the values into the molarity formula:
Molarity (M) = 0.0003086 moles / 0.1 Liters ≈ 0.0031 M
Therefore, the molarity of the 1.8% NaCl solution is approximately 0.0031 M.