Question

Please check my first 4 answers and help with the last question?!

Answer 1

Question.
What is the mole fraction of K in 55.3 g KBr dissolved in 350 g of water (H2O)? Atomic masses: K= 39.0 g/mol; Br= 79.9 g/mol H=1.0 g/mol O=16.0 g/mol
a) What is the solute’s molar mass?
b) Convert grams of solute to moles of solute using molar mass as a conversion factor.
c) Determine the solvent’s molar mass.
d) Convert grams of solvent to moles of solvent using molar mass as a conversion factor.
e) What is the mole fraction of K?

Answer.
a) 39.0 g/mol + 79.9 g/mol = 118.9 g/mol
b) 55.3 g / 118.9 g/mol = 0.465 mol
c) (1.0*2) + 16.0 g/mol = 18.0 g/mol
d) 350 g / 18.0 g/mol = 19.4 mol
e) ?

Answer 2

@rock_mit182

Answer 3

let me remember something mole fraction (x) = a mol/ (a+b) mol ?

Answer 4

seriously i don't know by memory the formulas