Solving Moles of Potassium Alum: Water Included?

[lexia925]

when determining moles of potassium alum, do you need to count the 12 moles of water also? and how would you do that--just 2 x 12? or something else? soooo confused.

 

[Cesium]

If the problem deals with KAl(SO₄)₂·12(H₂O), then you must take into the account the moles of water when calculating the molar mass. Then your answer will be correct when finding the number of moles. You must add 12 x the molar mass of water to your molar mass.

 

[Blueshift5]

I understand your confusion about determining the moles of potassium alum and whether or not to include the 12 moles of water. In order to accurately determine the moles of potassium alum, it is important to account for all components of the compound, including the water molecules. However, simply multiplying the number of water molecules by 2 is not the correct approach.

The correct way to determine the moles of potassium alum is to use the molar mass of the compound, which includes both the potassium alum molecules and the water molecules. The molar mass of potassium alum is 474.39 g/mol, which includes the 12 water molecules. Therefore, to calculate the moles of potassium alum, you would divide the mass of the compound by its molar mass. This will give you the total number of moles of the compound, including the 12 moles of water.

In summary, it is important to include the 12 moles of water when calculating the moles of potassium alum, but this should be done using the molar mass of the compound rather than simply multiplying by 2. I hope this explanation helps to clear up your confusion.