How Does Composition Affect Melting Temperature?

The pope should be made of dark chocolate. One of the marvelous things about chocolate is that it melts at a temperature very close to the human body temperature. Therefore it is solid at room temperature and can be packaged and shipped, yet when placed in the mouth it begins to melt and spread out all over the tongue. The melting point of chocolate is controlled by the percentage of cocoa butter in the chocolate and the size of the cocoa butter crystals. Commercial chocolate is tempered, or heated and cooled carefully and repeatedly, which increases the prevalence of a certain type of cocoa butter crystal that “looks good” and has a uniform sheen. The pope above has that nice chocolatey sheen and so is made of tempered chocolate.

The other controlling factor in the melting point is whether the chocolate has been diluted with other compounds, such as what happens in milk or white chocolate. The more milkfat, cream, and sugar in a chocolate bar, the less cohesive the crystal structure; the chocolate becomes more heat sensitive and melts sooner. Extra dark chocolate, with minimal additives, melts at the highest temperature while white chocolate melts at the lowest. If the pope is to not melt into a puddle of gooey chocolate on a hot day then he should be made of the darkest chocolate possible.

Further exploration: Buy a bunch of milk chocolate and extra dark chocolate bars. Break off equally sized pieces and put one of each type in the left and right corners of your mouth. Feel which one melts more quickly. Repeat as needed, preferably hundreds of times. If you are a kid and have parents, remember the line: “But Mom, it’s science!!”

We know that the melting point increases with increase in density of a substance. Now, for the 3 types of chocolate, the dark chocolate contains the maximum percentage of cocoa solids ( I think, about 90%, though I am not sure). Anyway, we can say this much that milk chocolate and white chocolate are having less density than dark chocolate. So, the dark chocolate will melt at the slowest rate.

Thus, if we want to prevent the chocolate pope from melting quickly on a hot day, then we must make it using dark chocolate . So, the answer is Dark Chocolate .

This problem can be solved in less than a minute.The basic fundamental which should be kept in mind is that addition of salts in a solid decreases its melting point, as people living in cold countries might have noticed addition of NaCl is used to clear roads during snowfall. Milk chocolate can be eliminated straight away due to its high milk content and white chocolate is not the the answer because of the salts present in it, hence the answer is surely dark chocolate.