Experimental cookery

Add a small portion of the sucrose to one of the containers of water. Stir until all is dissolved. Add another portion of sucrose and continue until you have as much of the sucrose in solution as can be dissolved. Take the tem- perature of the solution w^hile the sugar is dissolving. The stirring should be continued at intervals for 1 hour. Weigh the sucrose that is left and subtract the amount from 60 grams to obtain the amount dissolved. Your results v^^ill be only approximate for solubility should be determined in flasks to prevent evaporation. However, the results that you obtain will show the compara- tive solubility of the different sugars. If any undissolved sucrose remains after stirring for some time, set the container in warm water and stir until all the sucrose is dissolved. Put the container away in the laboratory and look at it occasionally to watch the growth of crystals. Compare the crystals formed with those of other sugars. Repeat the above directions for each sugar. For the less soluble dextrose and maltose add smaller portions when dissolving the sugars. Lactose has the least solubility of the above sugars and should be added in very small portions. Kind of sugar Grams dissolved Temperature of water at first Temperature while sugar is dissolving Sucrose Levulose Experiment 2. To determine the boiling point of water at the elevation above sea level at which you live. Place 1 pint of water in a sauce pan. Heat slowly. Notice the temperature at which bubbles begin to form on the sides and bottom of the pan. Of what are these bubbles formed? What becomes of them? At what temperature do the vapor bubbles begin to form? Do the first ones reach the surface of the water? At what temperature does the water boil? Are you at sea level or above it? What is the boiling point of water at sea level? Observe the surface of the liquid and the size of the bubbles. Heat the water so that the bubbles form rapidly. Is the temperature the same as when the bubbles form slowly? How do the surface of the water and the size of the bubbles compare with those of the slow-bubbling liquid? Does the temperature rise? Explain. Compare the temperatures registered by the thermometer when held in the water so that the thermometer bulb does not touch the bottom of the pan and when it touches it. Compare the temperatures registered when the bulb of 72 SUGAR COOKERY the thermometer is only partially Immersed and when it Is immersed so that there Is ^ to 1 Inch of water above the bulb. How should you apply these results to cooking sirups to a definite temperature In class results? Is the tem- perature the same when the thermometer bulb touches the bottom at the center and at the sides of the pan? (This may or may not vary according to the type of gas burner or the electric unit used.) Temperature Slow- bubbling liquid Rapid- bubbling liquid Temperature When bulb of thermometer is partially immersed When bulb touches the bottom of pan Type of bubble Breakj Results and conclusions. Experiment 3. To determine the effect on the boiling point of water when a soluble sub- stance is added.