Chocolate investigation

Aim: To investigate the difference between the melting point of dark and milk chocolate. Hypothesis: If both chocolate is heated then dark chocolate will melt faster because milk chocolate has more fats Variables (i)Independent: Two substances will be tested dark chocolate and milk chocolate. (ii)Dependent: The temperature at which each substance melts as measure by a thermometer once for each substance. (iii)Constant: The apparatus and external environmental factors including using the same chocolate manufacturer for both substances. Method: Equipment:

Beaker, iron Stand, iron clamp, Bunsen burner, wire gauze, test tube, thermometer and lighter 1.

Set up an iron clamp with a wire gauze on an iron stand then put a Bunsen burner beneath it. 2. Put 150 milliliters of water into the beaker. 3. Put the beaker on the wire gauze. 4. Put the test tube into the beaker and clamp in place. 5. Cut chocolate into the same size by using ruler to measure. 6. Put chocolate into the test tube.

7. Place a thermometer into the test tube. 8. Light the Bunsen burner with a lighter. 9. Wait until chocolate is melting. 10. Take notes of the temperature of the melting point.

Repeat as many times as possible in the time given. Data Collection: SubstanceTemperature (C) of the melting point Dark Chocolate40 Milk Chocolate51 Data processing GroupMean melting point temperature (C) Dark chocolate43 Milk chocolate50 Conclusion and Evaluation: (i) Conclusion 1. Comment on your hypothesis- was it support by your data or not? My hypothesis was correct according to what my data shows. I said that if both of the different chocolates were heated then the dark chocolate would melt faster, and this was shown to be true by the data collected.

2. Describe the relationship/trend in your data (Use numbers) – Only one number was collected for each substance, which does not allow for comments on relationships or data trends. 3. Comment on the reliability of the data (Comment on the range of your data) The data acquired in this lab is not highly reliable because only one data point was collected for each substance and only one trial was completed. However, the class average data is more reliable because these values combine the result of multiple trials. 4.

Explain result using scientific language-Explain the science of your experiment In my experiment I found out that milk chocolate melts slower than dark chocolate. It can be expected that the two substances have different melting temperatures due to the different composition of each. It may also be true that even two chocolates of the same type but from different manufacturers could have different melting points for that same reason. 5. Compare result to known data (Reference) My result is opposite of what the Internet concludes.

Dark chocolate and milk chocolate melt at different speeds because they have different ingredients. According to “The Joy of Cooking,” adding milk to chocolate causes it to become more heat sensitive. This means that milk chocolate melts at a lower temperature and faster than dark chocolate. It is not possible to determine whether the findings of this experiment are incorrect based on comparison with literature. While the literature casts doubt on the results, one would expect widely varying results due to differences in manufacture and transport of the chocolate tested.

Barlow, S “The Melting Time of Dark Chocolate Versus Milk Chocolate | EHow. com. ” EHow | How to Videos, Articles & More – Discover the Expert in You. | EHow. com. Web. 24 Nov. 2011. . hersheys. com. “Physical Properties of Chocolate” . Available: http://www. hersheys. com/nutrition-professionals/chocolate/composition/physical-properties. aspx. (ii) Evaluate of the method 1. Identify weaknesses in the method How well did the instruments for measuring work? (Was it precise enough? ) The recording method for collecting data with a thermometer is slightly inaccurate because it requires human observation of the temperature.

The composition of the chocolate used in this experiment is very uncertain because the manufacturing company for this chocolate may have used very different methods. The tempering of the chocolate could have been altered in some way before the experiment took place, which would have changed the crystalline structure of the chocolate, therefor, changing the melting point. The manufacturing specification of “dark” and “milk” chocolate are very broad. 2. Were there any factors that may have affected your data? Some of the heat in the apparatus may have escaped which may have caused a slightly inaccurate reading of the melting point.

3. Suggest realistic improvements A more accurate measurement could have been made with a digital temperature probe because it would reduce observational errors. A cover could have been placed over the beaker in order to keep the heat inside the apparatus. The beaker could have been wrapped with some sort of insulator that would have kept the heat in as well. 4. Suggest another experiment to support your data. Another experiment could be testing to see which chocolate melts faster in your mouth which can tell you which chocolate has a lower melting point.