What mass in grams of solid KCl would need to be added to 50

What mass (in grams) of solid KCl would need to be added to 500 grams of water to make an ideal solution with a boiling point of 106.8

Solution

let the mass be m.so,

number of moles=m/74.5

so molality=(m/74.5)*2

so,

6.8=0.512*2*(m/74.5)

or m=494.727 grams