A 3.0 molal solution of naphthalene in cyclohexane boils at 89.4 C. What is the boiling point of pure cyclohexane? Although solid naphthalene is slightly volatire, assume its volatility is zero in this calculation. The constant kb for cyclohexane is +2.80 Km^-1.

can someone help?

delta T = K_b m
You know K and m so delta T can be calculated. b.p.(soln)= normal b.p. + delta T. Check my thinking.