Sugar Cube Weathering Lab Name: _________________________________________ period:______ Date: ______________ Group Members: _____________________________________________________________________________ Part 1 PURPOSE: you will analyze and investigate a mechanical weathering process. MATERIALS: 1 container, 4 sugar cubes, scale, paper towel. HYPOTHESIZE: Predict what will happen to the sugar cubes after shaking them in a container. Hypothesis ( If/then ): ________________________________________________________________________________ __________________________________________________________________________________________________ PROCEDURES: 1) 2) 3) 4) 5) 6) 7) 8) 9) Using the balance, find the initial mass (g) of all 4 sugar cubes and record it in the data table (0 shakes). Make a sketch in the data table of what one of the sugar cubes looks like before shaking. Place the sugar cubes in the container and secure the lid. Shake the container 50 times. (keep your shakes consistent in force) Remove just the 4 sugar cubes. (leave the loose sugar in the container) measure the mass of all 4 sugar cubes and record it in the data table. Repeat procedures #3–#6 3 more times (the only other sketch you need to make is after 200 shakes). Find the total change in mass throughout the experiment. Total Change = Initial mass – final mass Construct an X-Y scatter plot (line) graph that represents the # of Shakes vs. Mass (g). PART 1: DATA TABLE # of Shakes (Independent Variable) 0 Shakes (initial mass) After 50 Shakes After 100 Shakes After 150 Shakes After 200 Shakes (final mass) Total Change in Mass (initial mass – final mass) Sketch of 1 Sugar Cube Mass of all 4 Sugar Cubes (g) (Dependent Variable) Analyzing Results Using the Independent and Dependent variables, write a proper title for this lab on the line below. Then, finish labeling the Xaxis and Y-axis values, label each axis with the correct variable, and graph your data. 0 0 Conclusion Questions 1) Describe in detail the physical changes to the sugar cubes after 200 shakes (before and after): ____________________________ ________________________________________________________________________________________________________ ________________________________________________________________________________________________________ 2) What is the name of the weathering process that was simulated in this lab? __________________________________________ 3) Explain where and how this type of weathering would be observed in nature. _________________________________________ ________________________________________________________________________________________________________ ________________________________________________________________________________________________________ 4) How does time affect Physical weathering and how did you observe that in this laboratory experiment. ____________________ ________________________________________________________________________________________________________ ________________________________________________________________________________________________________ Part 2 PURPOSE: Students will investigate the chemical weathering process of Dissolution. Dissolution occurs when minerals are completely dissolved into a liquid, such as water. One of the only ways to get the minerals back out of the water is to cause the water to evaporate, and the minerals will then “precipitate” out of the liquid and crystallize. MATERIALS: 2 beakers, 2 sugar cubes, 2 spoons for stirring, warm water, paper towel, and a timer. HYPOTHESIZE: Predict which form of sugar (Cube or Crushed) will weather (or dissolve) at a faster rate. Hypothesis ( If/then ): __________________________________________________________________________ __________________________________________________________________________________________ PROCEDURES: 1) Place one of your sugar cubes on a paper towel and fold the towel around the cube. 2) Use a heavy object to carefully crush the cube; try not to lose any of the sugar crystals in the process. 3) Fill both beakers about 2/3 full with warm water. 4) At the same time, place the full cube in one beaker and the crushed cube in the second beaker. 5) Start your timer, and use the spoons to gently stir each beaker at the same rate. 6) Record the amount of time it takes for each form of sugar to completely dissolve in the water. Record your times in seconds (for example, 1 min. 25 sec. would be written as 85 seconds). PART 2: DATA TABLE Form of Sugar Time to Dissolve (sec) Time to Dissolve (sec) (Independent Variable) (Dependent Variable) Class Average FULL Sugar Cube CRUSHED Sugar Cube PART 2: Conclusion questions. 1. Which form of sugar dissolved faster, crushed sugar or the sugar cube? __________________________ 2. Explain why that form of sugar dissolved at a faster rate: (use “surface exposure” in your answer) ___________ ____________________________________________________________________________________ 3. Were these changes due to chemical or physical weathering? __________________________________ 4. Describe the relationship between Surface Area and Rate of Weathering (use increases and/or decreases): ____________________________________________________________________________________ 5. What must you do in order to get the dissolved sugar back out of the water? ______________________ _____________________________________________________________________________________
