How do you prepare 2% Cu S04? How does this solution differ from 2M CuS04?

I am stumped. Thank you.

Deb

You don't specify if this is 2% w/w or 2% w/v. I'll assume you mean 2% w/v.

2% w/v CuSO4 means 2g CuSO4 in 100 mL soln which is the same as 20 g CuSO4 in a L.
2M soln means 2 mols CuSO4/L soln and 2 mols CuSO4 = approximately 2*159.6 g CuSO4 or about 319 g CuSO4/L for a 2M soln.

Dr. Bob, thanks for answering. What does w/w and w/v and soln mean? i am an a student in chemistry but am having difficulty with this piece.

Deb

w/w means weight/weight. Also called m/m for mass/mass. Five % m/m or w/w solution means 5.00 g solute/100 g solution.

w/v means weight/volume. Also called mass/volume. Five % solution m/v or w/v means 5.00 g solute/100 mL solution.
soln is my abbreviation for solution.
There also is a v/v. A 5% v/v means 5 mL solute/100 mL solution.

Dr. Bob, thank you kindly. Do you know if copper sulfate is considered an mm solution?

Thanks.

Deb

No. The solution is whatever you want to make it. If it isn't specified then the author of the problem just didn't add that information to the problem. I have always been told that if it isn't specified to consider it m/m (w/w) but that isn't a rule.

Thank you. You have been so helpful. I appreciate it.

Deb

To prepare a 2% CuSO4 solution, you will need to know the molecular weight of CuSO4 and the desired volume of the solution.

1. Calculate the amount of CuSO4 needed:
- Determine the molecular weight of CuSO4, which consists of copper (Cu) with a molecular weight of 63.55 g/mol, sulfur (S) with a molecular weight of 32.07 g/mol, and four oxygen (O) atoms with a combined molecular weight of 64 g/mol (16 g/mol each).
- Add up the atomic weights: 63.55 g/mol + 32.07 g/mol + 64 g/mol = 159.62 g/mol
- To prepare a 2% solution, multiply the desired volume of the solution (in liters) by 2% (or 0.02), and then multiply that by the molecular weight of CuSO4.
- Amount of CuSO4 needed (in grams) = Volume (in liters) × 0.02 × 159.62 g/mol

2. Dissolve the CuSO4:
- Weigh out the calculated amount of CuSO4 using a balance.
- Transfer the CuSO4 to a container, such as a beaker.
- Add distilled water to the container and stir until the compound is completely dissolved.
- Ensure that the final volume of the solution matches the desired volume.

A 2% CuSO4 solution will contain 2 grams of CuSO4 per 100 mL of solution.

Now, let's compare this 2% CuSO4 solution with a 2M (molar) CuSO4 solution.

A 2% CuSO4 solution represents a percentage concentration, where the solute concentration is expressed as a percentage of the total solution. In this case, 2% means 2 grams of CuSO4 dissolved in 100 mL of solution. The unit is weight/volume (w/v).

On the other hand, a 2M CuSO4 solution represents a molar concentration, where the solute concentration is expressed in moles per liter. In this case, 2M means 2 moles of CuSO4 dissolved in 1 liter of solution. The unit is moles/liter (mol/L).

In summary, the main difference between a 2% CuSO4 solution and a 2M CuSO4 solution is the way the concentration is expressed: one as a weight/volume percentage and the other as a molar concentration.