Calculate the mass percent of water in the hydrate Al2(SO4)3·18H2O to four sig. figs.

I got this answer 60.23, but I just am confused on how to correctly write the units

Well, when it comes to writing units, it's important to keep things clear and concise. In this case, the mass percent is typically written with the unit "%" or "wt%". So, the correct way to write the mass percent of water in the hydrate Al2(SO4)3·18H2O to four significant figures would be 60.23%.

However, if you're feeling a bit more playful, you could write it as "60.23% - water, because it's hydrate-larious how much water is in there!" 😄

To calculate the mass percent of water in the hydrate Al2(SO4)3·18H2O, you need to determine the mass of water and the mass of the hydrate.

Step 1: Find the molar mass of water (H2O):
H = 1.01 g/mol
O = 16.00 g/mol
Total molar mass of water (H2O) = 1.01 g/mol + 1.01 g/mol + 16.00 g/mol = 18.02 g/mol.

Step 2: Calculate the molar mass of the hydrate Al2(SO4)3·18H2O:
Al = 26.98 g/mol
S = 32.07 g/mol
O = 16.00 g/mol
Total molar mass of Al2(SO4)3 = (26.98 g/mol x 2) + (32.07 g/mol x 3) + (16.00 g/mol x 12) = 342.14 g/mol.
Total molar mass of the hydrate = 342.14 g/mol + (18.02 g/mol x 18) = 684.40 g/mol.

Step 3: Calculate the mass of water:
Mass of water = (molar mass of water / molar mass of the hydrate) x 100%
Mass of water = (18.02 g/mol / 684.40 g/mol) x 100% = 2.633%.

So, the mass percent of water in the hydrate Al2(SO4)3·18H2O is approximately 2.633%.

To calculate the mass percent of water in a hydrate, you need to determine the mass of water and the total mass of the hydrate.

In this case, the hydrate is Al2(SO4)3·18H2O. To calculate the mass percent of water, you need to find the molar mass of water (H2O) and multiply it by the number of water molecules in the hydrate (18).

The molar mass of water is 2(1.008 g/mol) + 16.00 g/mol = 18.02 g/mol.

Next, you need to find the molar mass of the hydrate Al2(SO4)3·18H2O. The molar mass of Al2(SO4)3 is 2(26.98 g/mol) + 3[32.06 g/mol + (4(16.00 g/mol))] = 342.15 g/mol.

Now, calculate the mass of water in the hydrate:
Mass of water = molar mass of water × number of water molecules
Mass of water = 18.02 g/mol × 18 = 324.36 g.

To find the total mass of the hydrate, you need to add the molar mass of Al2(SO4)3 and the mass of water.
Total mass of hydrate = molar mass of Al2(SO4)3 + mass of water
Total mass of hydrate = 342.15 g/mol + 324.36 g = 666.51 g.

Finally, you can calculate the mass percent of water in the hydrate using the formula:
Mass percent of water = (mass of water / total mass of hydrate) × 100
Mass percent of water = (324.36 g / 666.51 g) × 100 = 48.67%.

Therefore, the correct answer for the mass percent of water in the hydrate Al2(SO4)3·18H2O, to four significant figures, is 48.67%.

I don't know how you obtained that answer but the unit is %. The molar mass of Al2(SO4)3.18H2O is 666.429 and 18 mols H2O = 324.275

so %H2O = about (324/666)*100 = ?%.

You can do it more accurately.

48.65