1. The problem statement, all variables and given/known data Assume that a wax candle with mass m at temperature T1 undergoes constant heat admission dQ/dt=Kp Assume: m=50g T1=25 celsius Kp=10W Calculate how long it will take for the wax to melt and vaporise during constant heat admission without any loss. Data: ρ=791 kg/m3 M=310 g/mol Tm=317.15 K (melting temperature) Lf=252 kJ/kg Tb=641.8 K (boiling temperature) Lv=105 kJ/kg Cp(s)=598.1 J/mol K Cp(l)=739 J/mol K Cp(g)=1193 J/mol K 2. Relevant equations P=Q/Δt Q=mL Q=mcΔT 3. The attempt at a solution Well the posibilities overwhelmes me. I know that it all boils down to using Δt=Q/P the question is though which Q are they asking for, I have only made an attempt at the boiling question though. For boiling If I apply what I know from heat of transformation: Q=mL Q=0.05kg*252 kJ/kg -> Q=12600J Thereby: Δt=12600J/10W -> Δt=1260s In other words it would take 21mins. However if that's the case then it would be even faster to boil it away when it's in liquid. Am I doing something wrong or is there something blatantly obvious that I don't seem to get?