find the mole fraction of sodium in 25% by massof sodium amalgum
To find the mole fraction of sodium in sodium amalgam, you need to know the molar masses of sodium (Na) and mercury (Hg), as well as the mass percentage of sodium in the amalgam.
1. Determine the molar mass of Na: The molar mass of sodium is 22.99 g/mol.
2. Determine the molar mass of Hg: The molar mass of mercury is 200.59 g/mol.
3. Calculate the mass of sodium in the amalgam: If the amalgam contains 25% by mass of sodium, then for every 100 grams of amalgam, 25 grams of sodium are present.
4. Calculate the mass of mercury in the amalgam: Since the total mass of the amalgam is 100 grams, and 25 grams are sodium, then the remaining 75 grams must be mercury.
5. Convert the mass of sodium and mercury to moles using the molar masses: To convert grams to moles, divide the mass of the substance by its molar mass.
Moles of sodium (Na): 25 grams / 22.99 g/mol = 1.09 mol
Moles of mercury (Hg): 75 grams / 200.59 g/mol = 0.374 mol
6. Calculate the mole fraction of sodium: The mole fraction is the ratio of the moles of sodium to the total moles of both sodium and mercury.
Mole fraction of sodium (XNa) = Moles of sodium / (Moles of sodium + Moles of mercury)
XNa = 1.09 mol / (1.09 mol + 0.374 mol) = 0.744
Therefore, the mole fraction of sodium in 25% by mass of sodium amalgam is 0.744.