## Chemistry: A Molecular Approach (3rd Edition)

73$^{\circ}$J
1. Connect two scales into one expression $\frac{J-17}{80}=\frac{H}{120}$ 2. Simplify the expression multiplying both sides by 40 $\frac{J-17}{2}=\frac{H}{3}$ 3. Given H=84, just substitute and solve for J: $\frac{J-17}{2}=\frac{84}{3}$ $3J-51=168$ $3J=219$ $J = 73$ 4. Therefore, boiling point of methanol in J scale is 73.