Project 1: Calorimetry CHM2046L-029 24920 Introduction Background Calorimetry is a method of measuring the enthalpy (heat energy gained or released) of various state changes, such as chemical reactions. Calorimetry can also be used in a number of other ways, however, including in microbiology (where the presence of various microorganisms can be determined as their multiplication increases thermal power) and in environmental science (where a calorimeter can be used to determine insect metabolism as it varies based on changes in such factors as temperature and chemical treatments)1. There are numerous kinds of calorimeters, each with their own advantages and disadvantages, such as those that maintain a constant pressure …show more content…
Objectives The objective for the first week of the experiment was to construct a coffee cup calorimeter and determine its heat capacity through the mixing of water of two different temperatures inside the calorimeter. In the second week of the experiment, we performed three trials of acid-base reactions in each calorimeter (coffee cup and commercial) in order to compare the resulting enthalpy values to the theoretical ones and eventually determine which kind is more efficient and accurate. Methods Part 1 Methods Cardboard and two Styrofoam cups were obtained. A circle of cardboard big enough to fit snugly just under the rim of a cup was cut out and placed slightly below the rim of one cup. The cup with the cardboard lid was stacked inside the other cup. A hole in which the thermometer could fit snugly was poked into the cardboard lid, and aluminum foil with a hole of the same size was placed over the cups to provide extra insulation. The commercial calorimeter provided for the experiment and two thermometers were also
The temperature probe was then quickly cooled to room temperature. When this was achieved, the hot water was immediately transferred into the calorimeter. This method of keeping the temperature probe cooled before measuring a new temperature was repeated throughout the entire experiment. Temperature data was collected for 180 s while swirling the temperature inside the calorimeter. The calorimeter still contained the warm water.
During this investigation, I strived to figure out if an endothermic or exothermic reaction occurs in a cold pack. This goal was formed based on the guiding question: What type of chemical reaction occurs in a cold pack? To conduct this investigation, I began by creating a list of procedures to follow in order to stay on track and work efficiently. Firstly, I had to collect the materials I needed and work out the correct amounts of each substance to use in order for the reaction to work correctly.
The molar heat of combustion of a compound is 1250 kJ/mole. If 0.115 moles of this compound in a bomb calorimeter with 2.50 L of water, what would the temperature increase be? If change in heat is positive it is an _______ reaction If change in heat is negative it is an_______ reaction
As mentioned in the hypothesis, the prediction is that as the temperature increases towards the optimal, the rate of respiration will increase. As the temperature exceeds the optimal, the rate of respiration will decrease. The temperature of the environment can be varied by placing the respiration chamber under a temperature-controlled water bath/cooling bath. The temperatures that will be used in this experiment will range from 0ºC to 50ºC in 10ºC increments. Digital thermometer will be used to measure the temperature of air.
The topic that the scientist has researched is the reaction rate of different particle sizes. In the experiment, the scientist will discover how the particle size of Alka Seltzer affects the rate of chemical reaction with water. The independent variable in the experiment is the particle size of the Alka Seltzer, while the dependent variable is the rate of reaction, or the volume of Carbon dioxide. The volume of carbon dioxide will be measured in ml. Also, a few of the constants in the experiment will be the amount of water, and amount of tablets.
Modifications of this procedure include the use of hot plates instead of Bunsen burners, and heating t-butyl alcohol to 60-65 ℃ instead of 50 ℃. Other modifications include the use of weighing boats to measure an amount of unknown instead of weighing paper, and completing one run of unknown 2 instead of two runs of unknown 2. Summary of
The items that were massed were the evaporating dish, watch glass, and NaCO3. The materials were massed once before and once after being heated in the drying oven. The mass of the evaporating Dish before was 46.57 g; while after being heating was 60.15 g. The mass of the watch glass before was 57.97 g and after was 48.75g. There were two masses taken for the substance NaHCO3- one with the evaporating dish and one without, subtracted out after the lab was concluded. The mass of the substance with the dish was 48.79 g before and 62.33 g after; meanwhile, the mass of the substance without the dish was 2.22 g before and 2.18 g after. The mass of the NaHCO3 had changed after the reaction occurred along with after it was placed on the hot plate and being in the drying oven.
After seeing this data the two most effective look chemical at resisting energy was CaCl2 and LiCl. So we looked at the price of both of this chemical CaCl2 cost 6.55$ per 500g and LiCl cost 32.75$ per 500g because CaCl2 was substantially cheaper we decide to chose it to use in own hand warmer. We calculated that it would take 22g of CaCl2 to create a 20oC increase in temperature of 100ml of water. Some sources of error in this lab, would be heat escape from not be able to replace the lid of the calorement went adding chemical into it, inaccuracies in the balance, and not waiting of the proper time to recode the
Name: Angela Toledo Sex: Female Age: 18 Activity Level: Moderate Part 2 – Analysis and Discussion Macronutrients Nutrient Mean Intake Recommended Intake Comparison Calories 1280 2400 -1120 Carbohydrates (grams) and (% calories) 173g 54% Cal 130g 45-65% Cal Within recommendation Dietary Fiber (grams) 11g 26g -15
Introduction: In this assignment, I will be doing two experimentations on examining the impact of temperature on the Alka-Seltzer’s response time. The first experimentation that I will be doing involves some water that is room temperature. The second experimentation that I will be doing involves some water that is very hot. If I want to be able to figure out the impact of the temperature on water, I will have to document the time it will take for the Alka-Seltzer to go into solution.
The control in the experiment is water. Units used while timing the productivity of gas from an Alka-Seltzer tablet in different temperatures is, seconds. In order to find out if temperature controls the rate of chemical reaction, whether hot water is a more effective way to make the gas produce at a faster speed, it would be necessary to compare the results of different temperatures at the end of each trial. In order to do this the scientists will measure the volume of gas that is produced within a 10 second interval time after the tablet begins to react.
Utilizing the method that the experimenters have come up with, the procedure isolates the variable being tested, which is the paper towel brand. By not changing other aspects of the procedure, other factors have a lower chance of affecting the accurate results of the answer to the main question. Additionally, the method is a quick and simple experiment, causing no use of excessive time than the provided duration. Within the first minutes of the experiment, the experimenters and the advisor realized that the method did not really provide accurate results due to merely estimating the numbers without the use of a graduated cylinder. Changing that aspect of the procedure by using a graduated cylinder to measure the amounts of water instead helped
Coffee vs energy drinks, who will win? People drink coffee and energy drinks because they wake you up and they get you ready for the day. Most energy drinks hold 8.4 ounces. On the other hand, coffee has 8 ounces. On the healthier side, coffee only has 1 calorie for 8 ounces while energy drinks have 110 calories for 8.4 ounces.
Place the the beaker onto a hot plate that is on a low heat setting (about setting 3). Every 5 minutes for 20 minutes, measure the circumference of the balloon and record it in Data Table A. You can measure the circumference of the balloon by looping a piece of string around it then using a ruler to measure the string’s length. Record the data in the data
Record the readings for the time taken, for the particular height (the paper cup was dropped from). Repeat this process (using the same equipment), by varying the height of paper cup from the ground (with a specific difference in height, in each experiment). The independent variable, which is the height the empty muffin paper cup is dropped from, will start at 1 metre and the increase in height will be 0.5 m in each experiment. The use of the clamp stand is effective in this experiment because it will always control or keep constant, the height in which the paper cup is dropped from, unlike somebody dropping the paper cup using his/her hands.