[填空题]
A 100g chocolate bar is placed onto a hot plate. Thhhubxg-jni41-be (if 8s n- w*e chocolatel7, p7d.,zuvi/ qwz+lle: bf m is initially at its mel:ep z.f7/b,vl7lz q wiu,ml+dting temperature of $30^{\circ}C$.
Heat is transferred from the plate to the chocolate at a constant rate $P_{in}$ of 12W, causing it to melt at a constant rate of $6\,g\,min^{−1}$. After all the chocolate has melted, the liquid chocolate continues to heat to a temperature of $353\,K$.
Specific heat capacity of melted chocolate = $1.0\,kJkg^{−1}K^{−1}$
Specific latent heat of fusion of chocolate = $50\,Jg^{−1}$
1.State how the kinetic and potential energy of the chocolate change as it melts.
2.(1)Determine the amount of energy required to heat the liquid chocolate from the melting temperature to 353K. ΔE = kJ
(2)Show that approximately 58% of the supplied energy is lost to the surroundings while the chocolate is melting. $As\,a\,percentage\,of\,the total energy, this\,gives$ = %
3.The graph shows how the temperature of the chocolate changes with time.
Draw on the same graph a new line to show how temperature would change for a larger mass of chocolate with the same starting conditions.
