Calculate the molarity of a solution containing 58.5mg of NaCl in 2.50mL of solution.
mass NaCl = 58.5/1000 = ?
mols NaCl = mass/molar mass
M = mols NaCl/0.00250 L = ?
23.4 g/l
To calculate the molarity of a solution, you need to know the amount of solute (in moles) and the volume of the solution (in liters). In this case, we have the amount of solute in milligrams and the volume of the solution in milliliters. We need to convert these quantities to the required units.
First, let's convert the amount of solute from milligrams to grams. There are 1000 milligrams in a gram, so:
58.5 mg ÷ 1000 = 0.0585 g
Next, let's convert the volume of the solution from milliliters to liters. There are 1000 milliliters in a liter, so:
2.50 mL ÷ 1000 = 0.0025 L
Now that we have the amount of solute in grams and the volume of the solution in liters, we can calculate the molarity.
Molarity (M) is defined as moles of solute divided by liters of solution. The formula for calculating molarity is:
M = moles of solute / liters of solution
To calculate the moles of solute, we need to use the molar mass of NaCl, which is 58.5 g/mol. We divide the amount of solute in grams by the molar mass to find the moles:
moles of solute = 0.0585 g / 58.5 g/mol = 0.001 mol
Now, we can calculate the molarity:
M = 0.001 mol / 0.0025 L = 0.4 M
Therefore, the molarity of the solution containing 58.5mg of NaCl in 2.50mL of solution is 0.4 M.