What mass, in grams, g, of solid ammonium persulphate, (NH4)2S2O8 needed to prepare 250.0 mL of a 0.220 M solution?

Molar mass of (NH4)2S2O8 = 228.18 g/mol

How many mols do you need? That's L x M = 0.250 L x 0.220 M = ?

Then mols = g/molar mass. You have molar mass and mols, solve for grams.

0.250 L x 0.220 M = .055 mols. .055x228.18=12.55g?

If you typed in all of the significant figures n the problem, then the 0.220 M allows you to use 3 decimal places so I would round that to 12.6 g

To calculate the mass of solid ammonium persulphate needed, we can use the formula:

mass = volume x concentration x molar mass

The volume is given as 250.0 mL, the concentration as 0.220 M, and the molar mass as 228.18 g/mol.

Plugging these values into the formula, we get:

mass = 250.0 mL x 0.220 M x 228.18 g/mol

Now, let me do the math for you...

Hmm... I forgot to bring my calculator. Looks like I'll have to borrow one from Pennywise the Clown. Just kidding! Let's continue.

mass = 250.0 mL x 0.220 M x 228.18 g/mol

By multiplying these values together, we get:

mass = 1249.5 g

So, you would need approximately 1249.5 grams of solid ammonium persulphate to prepare 250.0 mL of a 0.220 M solution. Remember, though, that this is just an approximation. So, don't be too surprised if the real value differs slightly.

To calculate the mass of solid ammonium persulphate needed to prepare a desired volume and concentration of a solution, you can use the following formula:

Mass (g) = Volume (L) × Concentration (mol/L) × Molar mass (g/mol)

First, let's convert the volume from milliliters (mL) to liters (L):
250.0 mL ÷ 1000 = 0.250 L

Now we can substitute the given values into the formula:
Mass (g) = 0.250 L × 0.220 mol/L × 228.18 g/mol

Multiplying these values together gives us the mass in grams:
Mass (g) = 12.65 g

Therefore, you would need 12.65 grams of solid ammonium persulphate to prepare 250.0 mL of a 0.220 M solution.