Question

0.100 mole NaCl is dissolved into 100.0 g H2O. What is the mole fraction of NaCl?

how do i do this steps pls

Answer 1

Mol fraction NaCl = 0.0177

Step-by-step explanation:

Step 1: Data given

Number of moles NaCl = 0.100 moles

Mass H2O = 100.0 grams

Molar mass H2O = 18.02 g/mol

Step 2: Calculate moles H2O

Moles H2O = mass H2O / molar mass H2O

Moles H2O = 100.0 grams / 18.02 g/mol

Moles H2O = 5.549 moles

Step 3: Calculate total moles

Total moles = 0.100 moles + 5.549 moles

Total moles = 5.649 moles

Step 4: Calculate mol fraction of NaCl

Mol fraction NaCl = moles NaCl /total moles

Mol fraction NaCl = 0.100 moles / 5.649 moles

Mol fraction NaCl = 0.0177

Answer 2

Mole fraction NaCl = 0.017

Step-by-step explanation:

In order to determine the moles fraction we need to determine the moles of each, solute and solvent

Solute = NaCl

Solvent = Water

Moles of solute = 0.1 moles

Moles of solvent = 100 g . 1 mol/ 18g = 5.55 moles

Mole fraction of solute = Moles of solute / Total moles

Total moles = moles of solute + moles of solvent

Total moles = 0.1 + 5.55 = 5.65 moles

Mole fraction NaCl = 0.1 / 5.65 = 0.017