Specific heat of corn

Specific Heat Capacity Heat is energy that flows from something with a higher temperature to something with a lower temperature. The usual metric unit of heat is the calorie (cal – not the same as the Calorie, food energy, which equals 1000 calories). It takes 1 calorie of heat energy to raise 1 gram of water 1° Celsius (thus, its specific heat capacity is 11cal/g°C). The English unit for heat is the British Thermal Unit (BTU). It takes 1 BTU of heat energy to raise 1 pound of water 1° F. That value for water is an unusually high amount of heat to change the temperature of a substance. For instance, it only requires 1/6 of a calorie to heat 1 gram of sand, and only 1/33 of one calorie to heat 1 gram of lead 1° Celsius; in other words, a pound of sand on the stove would heat up 6 times faster than a pound of water. In fact, quart for quart, nothing takes more heat to warm it up, than does water (it is a very unique substance!). In this laboratory exercise, we will estimate a temperature change for mixed liquids, and determine the specific heat capacity of some things around the house. You will need: ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ ✓ Thermometer (Celsius) Scale that weighs in grams 4 12-oz (or larger) Styrofoam cups Beaker or Measuring Cup marked in mL Small pot of boiling water Pitcher of room temperature water Tongs Bottle of Glycerin or Corn syrup (you’ll need ~4 oz) Flour 1 Rock (no larger than an egg) 1 piece of metal (optional; ~25-50 g) Procedure I: 1) Set a pitcher of tap water (about 1 quart) on the countertop to come to room temperature (give it at least one hour). 2) Start a pot of water to boiling (at least 2 cups of water). 3) Place one Styrofoam cup inside of another. This will be our calorimeter – an apparatus for measuring quantities of heat. 4) Pour 100 mL (use beaker) of Room Temperature water from the pitcher into a Styrofoam cup. 5) Pour 100 mL of the boiling water into the calorimeter (the doubled Styrofoam cups). 6) Measure & record the temperature of the Room Temperature water in the cup; Measure & record the temperature of the hot water in the calorimeter. RT water: _____° C Hot water: _____°C 7) Pour the RT water into the hot water in the calorimeter. Predict the final temperature of the mixture. Predict temperature of mixture: _____°C 8) Stir well with the thermometer, then measure and record the temperature of the mixture after the thermometer has been in the cup for ~10 seconds. Measured temperature of mixture: _____°C Now, we’ll determine the specific heat capacity of some other samples. Procedure II: Specific Heat of glycerin or corn syrup 1) Weigh the dry, empty calorimeter (the doubled Styrofoam cups): (A) _____ g 2) Place ~100 mL of glycerin or corn syrup in the calorimeter and reweigh: (B) _____ g “I used __________________ [glycerine or corn syrup] for my procedure” 3) Pour 100 mL of hot water into a single Styrofoam cup (the cup used for Room Temp water above will work). Measure the temperature of each. Temperature of glycerin or corn syrup: (C) _____°C Temperature of hot water: (D) _____°C 4) Pour the hot water into the calorimeter and stir the mixture for several seconds with the thermometer, watching for the temperature to stop rising. Record the highest temperature of the mixture. Temperature of mixture: (E) _____°C 5) Calculate the specific heat capacity using the equation here. Specific Heat Capacity of Syrup: ______cal/g°C Sp.Heat syrup = 100x∆Tw/ms / ∆Ts ∆Tw = temperature change of water (temp hot water – temp mixture, D - E) ms = mass of sample (B - A) ∆Ts = temperature change of sample (temp of mixture – temp of sample, E - C) Procedure III: Specific Heat of Flour 1) Weigh out ~½ Cup of flour in a dry cup: (A) _____ g. Measure the temperature: (B) _____°C 2) Pour 150 mL of HOT water into the calorimeter. Measure the temperature: (C) _____°C 3) Add the flour and stir gently until well mixed. Measure the temperature: (D) _____°C 4) Calculate the specific heat capacity using the equation here. Specific Heat Capacity of Flour: _______cal/g°C Sp.Heat Flour = 150x∆Tw/ms / ∆Ts ∆Tw = temp change of water (temp hot water in calormtr – temp of water/flour mix, C - D) ms = mass of sample (the weight of the flour, A) ∆Ts = temp change of flour (temp of water/flour mix – temp of flour, D - B) Procedure IV: Specific Heat of Rock (one about the size of a walnut shell) 1) Weigh the rock: (A) _____ g. Place 100 mL of Room Temperature (RT) water in the calorimeter. Place the rock in boiling water 2) Measure the temperature of the boiling water: (B) _____°C and the RT water: (C) _____°C 3) Using tongs, remove the rock from the boiling water, and place into the calorimeter, and cover the cup with your hand with the thermometer in the water. Swirl gently and the highest temp. 4) Measure the temperature of the water/rock in the calorimeter: (D) _____°C 5) Calculate the specific heat capacity using the equation here. Specific Heat Capacity of Rock: _______cal/g°C Sp.Heat Rock = 100x∆Tw/ms / ∆Ts ∆Tw = temp change of water (hi temp of water/rock – temp of RT water, D - C) ms = mass of sample (the weight of the rock, A) ∆Ts = temp change of rock (temp of hot water – temp of water/rock, B - D) OPTIONAL: Try these procedures with other objects if you want (maybe something metal), for extra credit. ...