Question

How many grams of copper(II) fluoride are needed to make 6.7 L of a 1.2 M solution?

Answer 1

To make 6.7 L of a 1.2 M solution of copper(II) fluoride, 815.44 grams of the compound are required, based on the molarity formula and the molar mass of copper(II) fluoride.

Step-by-step explanation:

To calculate the number of grams of copper(II) fluoride needed to make a 1.2 M solution, we must first understand the concept of molarity, which is moles of solute per liter of solution. Knowing this, we can then use the formula:

Molarity (M) = moles of solute/volume solution in liters

For a 1.2 M solution, this means 1.2 moles of copper(II) fluoride are required per liter of solution. Since the desired volume is 6.7 L, the total number of moles needed is:

1.2 moles/L × 6.7 L = 8.04 moles

To convert moles to grams, we need the molar mass of copper(II) fluoride (CuF₂). The atomic masses of copper (Cu) and fluorine (F) are approximately 63.55 g/mol and 19.00 g/mol, respectively. Therefore, the molar mass of CuF₂ is:

(63.55 + 2×19.00) g/mol = 101.55 g/mol

Finally, to find the mass in grams:

8.04 moles × 101.55 g/mol = 815.44 grams

So, 815.44 grams of copper(II) fluoride are needed to make 6.7 L of a 1.2 M solution.

Answer 2

Answer: 816.40572 grams CuF2 OR 820 grams CuF2 (with sigfigs)

Explanation: To find the amount in grams, you first have to find it in moles and use the molar mass as a conversion factor to convert it into grams. To find the amount in moles you must switch around the formula for molarity. Molarity = number of moles / volume or M = n/V. As you can see, the unit for molarity is M or moles/liter and the units for volume is liters. All you have to do is switch the equation around so you are solving for number of moles, or n. The switched equation looks like n = MV. So, you just have to multiply the amount of liters and the molarity and then convert to grams. 6.7 liters*1.2 moles/liter = 8.04 moles CuF2 (the liters cancel out). Then you have to convert to moles: 8.04 moles CuF2*101.543 grams/mol CuF2 = 816.40572 grams CuF2. If you want the answer with significant figures, it would be 820 grams CuF2.