Find the percent by mass of sodium chloride in a 1.35 M NaCl solution. The density of the solution is 1.06 g/mL..............how do I go about doing this question thanks!
To find the percent by mass of sodium chloride (NaCl) in the solution, you need to know the molar mass of NaCl and the mass of NaCl in a given volume of solution. Here's how you can proceed:
1. Determine the molar mass of NaCl. The molar mass of NaCl is calculated by adding the atomic masses of sodium (Na) and chlorine (Cl). The atomic mass of sodium is 22.99 g/mol, and the atomic mass of chlorine is 35.45 g/mol. So, the molar mass of NaCl is 22.99 + 35.45 = 58.44 g/mol.
2. Calculate the mass of NaCl in a given volume of solution. You know that the solution has a concentration of 1.35 M, which means there are 1.35 moles of NaCl per liter of solution. To find the mass of NaCl in the solution, you can use the following equation:
mass (g) = volume (L) x density (g/mL)
Since the density of the solution is given as 1.06 g/mL, and we need to find the mass in grams, we'll need to convert the volume to milliliters (mL) and multiply by the density. Assuming you have 1 liter (1000 mL) of the solution, the mass of NaCl in the solution would be:
mass (g) = 1000 mL x 1.06 g/mL = 1060 g.
3. Calculate the mass of NaCl. Now that you have the mass of NaCl in a given volume of solution, you can calculate the actual mass of NaCl using the molar mass of NaCl. Divide the mass of NaCl by the molar mass to find the number of moles:
moles of NaCl = mass (g) / molar mass (g/mol)
moles of NaCl = 1060 g / 58.44 g/mol = 18.15 mol.
4. Calculate the percent by mass. The percent by mass can be calculated using the following formula:
percent by mass = (mass of NaCl / mass of solution) x 100
Since you have already calculated the mass of NaCl as 1060 g, you just need to divide this mass by the mass of the solution. The mass of the solution is the mass of NaCl plus the mass of the solvent (water). If you don't have any additional information about the mass of the solvent, you won't be able to calculate the exact percent by mass. However, you can use the volume of the solution to make an approximation. Assuming you have 1 liter (1000 mL) of the solution, the mass of the solution can be approximated as 1000 g (since the density is given as 1.06 g/mL).
percent by mass = (1060 g / 1000 g) x 100 = 106%.
Therefore, the percent by mass of NaCl in the 1.35 M NaCl solution, with a density of 1.06 g/mL, is approximately 106%.