There are three ions per MgCl2 formula unit. Moles ion=3*.4 moles
molefraction=3*.4/(.4+47.2)
mole fraction =amount solute(in mols) /total amount of solute and solvent (in mols)
so wouldn't it be .400/ .400+ 47.2 which is the moles of water?
molefraction=3*.4/(.4+47.2)
Given:
- Moles of MgCl2 (solute) = 0.400 moles
- Mass of water (solvent) = 850.0 grams
To calculate the number of moles of water (solvent), we need to convert the given mass into moles using the molar mass of water.
The molar mass of water (H2O) is:
- 2(atomic mass of hydrogen) + atomic mass of oxygen = 2(1.008 g/mol) + 16.00 g/mol = 18.016 g/mol
Moles of water = mass of water (g) / molar mass of water (g/mol)
= 850.0 g / 18.016 g/mol
≈ 47.2 moles (rounded to one decimal place)
Now, we can calculate the mole fraction of total ions.
Mole fraction = Moles of solute / (Moles of solute + Moles of solvent)
= 0.400 moles / (0.400 moles + 47.2 moles)
= 0.400 moles / 47.6 moles
≈ 0.0084 (rounded to four decimal places)
Therefore, the mole fraction of total ions in the aqueous solution is approximately 0.0084.
Mole fraction = Amount of solute (in moles) / Total amount of solute and solvent (in moles)
In this case, the amount of solute is 0.400 moles of MgCl2 and the total amount of solute and solvent is the sum of moles of MgCl2 and moles of water.
First, let's calculate the moles of water. Given that the molar mass of water (H2O) is approximately 18.015 g/mol, we can determine the moles as follows:
Moles of water = Mass of water (in grams) / Molar mass of water (in grams per mole)
= 850.0 g / 18.015 g/mol
= 47.198 moles (rounded to 3 decimal places)
Now, we can calculate the mole fraction of total ions:
Mole fraction = 0.400 moles of MgCl2 / (0.400 moles of MgCl2 + 47.198 moles of water)
= 0.400 / (0.400 + 47.198)
= 0.00834 (rounded to 5 decimal places)
Therefore, the mole fraction of total ions in the aqueous solution is approximately 0.00834.