How many grams of CuCl2 are required to make 75 mLof a 0.20M solution?
To determine the number of grams of CuCl2 required to make a 0.20M solution in 75 mL, you need to use the equation:
Molarity (M) = (moles of solute) / (volume of solution in liters)
First, convert the volume of the solution from milliliters to liters:
75 mL * (1 L/1000 mL) = 0.075 L
Next, rearrange the equation to solve for moles of solute:
moles of solute = Molarity (M) * volume of solution in liters
moles of solute = 0.20 M * 0.075 L
Now, calculate the moles of CuCl2:
moles of CuCl2 = 0.20 M * 0.075 L = 0.015 moles
To determine the grams of CuCl2 required, you need to use the molar mass of CuCl2. The molar mass of CuCl2 is calculated by summing the atomic masses of copper (Cu) and chlorine (Cl):
CuCl2 = (63.55 g/mol Cu) + 2 * (35.45 g/mol Cl) = 63.55 g/mol + 70.90 g/mol = 134.45 g/mol
Finally, calculate the grams of CuCl2 required:
grams of CuCl2 = moles of CuCl2 * molar mass of CuCl2
grams of CuCl2 = 0.015 mol * 134.45 g/mol = 2.02 grams
Therefore, 2.02 grams of CuCl2 are required to make a 0.20M solution in 75 mL.