For part C, the concentration of was determined to be 1.01 mol/L, 0.973 mol/L, and 1.158 mol/L. These results show a relatively closed to the accepted 1.00mol/L of NaOH. The differences of these results are understandable since the concentration of NaOH would changes over time because during the transfer of NaOH powder in part A, it was exposed to the air, thus it could reacts with CO2 in the atmosphere to produce Na2CO3 and water, therefore, changing the concentration of NaOH. Furthermore, the NaOH could also react with the glass thus it wills also reducing its concentration. However, all of the concentration of NaOH that was determine are maximum of 0.158mol/L differences compare to the standard 1.00 mol/L, therefore, it can be concluded that the result are accurate. …show more content…
On the lid of the calorimeter, there were two holes and one was being used for the thermometer, and the second one was left open. This hole could have let heat to escape as the reaction was taking place which would have lowered the final temperature value. These conditions would have led to a lower final temperature value. To prevent even the slightest anomalies in the future, any holes on the calorimeter can be covered by tape or another item that could block the passage. The top of the calorimeter could also be covered with aluminum and this would not only cover the holes but would secure the space under the lid so any heat that may escape would stay within the area due to the aluminum. Aluminum could also be tucked in the space between the lid and the calorimeter to once again lock the heat in. This way, the calorimeter will be more effective and maintain all the heat of the reaction resulting in values that are completely accurate and decreasing even the slightest
Experimental Summary: First, my partner and I put the marshmallow and cheese puff on T-pins and used the Electronic Balance to measure the mass of each of them. Next, we put 100 mL of water in the 100 mL Graduated Cylinder and poured it into the 12 oz. soda can. We measured the temperature of the water with the thermometer. After
A: The reaction with water and vinegar was the most useful in this experiment. The physical properties were very self explanatory because the texture of the powders was all different expect icing sugar and cornstarch. Also the Ph levels were very similar of six and seven for corn starch and icing sugar respectively. d) Q: How confident do you feel about your identification of the
Tf-Ti). Next, subtract the initial temperature, 25 degrees from the final temperature, 29 degrees putting the change in temperature at 4 °C. To calculate the heat absorbed by the water in calorimeter, use the formula (q = mCΔT). Plug in 50 mL for (m), 4.184 J for (C) and 4 °C for the initial temperature (ΔT), then multiply.
To begin the experiment, we measured 5cc of water and 5g of NaCl and added them to a test tube. Next, we stoppered the test tube and shook vigorously for two or three minutes. After we observed that the solution was saturated and massed an evaporating dish (18.89g) and poured most of the solution into it, while being careful not to pour any undissolved solid into the dish. Next, we massed the evaporating dish with the solution and found it to be 23.32g. The next step was to slowly evaporate the solution in the evaporating dish using a hot plate. Once the liquid was evaporated from the solution, to the best of our ability, we massed the remaining solid in the dish, which we found to be 20.32g. This was the last step of the physical portion of the experiment, and we proceeded to the calculations. First, we found the mass of the remaining solid by subtracting the mass of the evaporating dish from the mass of the solid and evaporating dish, which we found to be 1.43g. To find the mass of the evaporated water we subtracted the mass of the solid and evaporating dish from the mass of the solution and evaporating dish, which we found to be 3g. Because the density of water is 1g/1cc, the mass is the ...
By adding fresh cold water it should cool the copper calorimeter. By making sure I do these checks before I do the experiment means that I should be able to get accurate results as the test will have been run fairly and hopefully successfully as there should not have been anything gone wrong. To make sure all the measurements are correct, I will also run checks. These checks when recording the data are. Make sure to check the thermometer to see what temperature the water is at the start, so I am able to see what it has to be when its been heated by 10 degrees.
Three cups of water were filled with 70 ml of water. Different concentrations of salt were put into the cups. One cup was left with no salt to serve as a control. The independent variable is the amount of salt put into each cup. The dependent variable is the density. The important constants to maintain are, the volume and temperature of water in the cups. The cups of water were then weighed on a triple beam balance to measure the mass which was recorded. Then as a second trial to improve accuracy the solutions were measured again.
A possible source of error could be loss of heat during the reaction that could have affected the final temperature results. Since a real calorimeter wasn’t used and a plastic cup calorimeter was used, there is a good chance that the system lost more heat to the surroundings than it would have if a real calorimeter had been used. That said, using the plastic cup calorimeter is a good substitute for a real calorimeter in classroom laboratory experiment because it still acts as an insulator to keep the heat inside and makes a better calorimeter than other materials because of its high specific heat.
1. The labels have fallen off of three bottles thought to contain hydrochloric acid, or sodium chloride solution, or sodium hydroxide solution. Describe a simple experiment which would allow you to determine which bottle contains which solution.
Indirect Calorimetry estimates the energy expenditure of the human body through measurements of expelled gases. Indirect calorimetry is not quite as accurate as direct calorimetry, which takes measurements of heat dissipated from the human body using heavy equipment, but it is less expensive to conduct experimentally, and provides one with the ability to measure oxygen consumption and carbon dioxide production. With these measurements, one gets a look into the overall aerobic physical fitness of the individual and their maximum oxygen uptake. Indirect calorimetry can also determine the primary source of energy being used using the Respiratory Exchange Ratio (RER). RER is non-invasive and provides information regarding the metabolic contribution of fat or carbohydrates.
- Temperature was measured after and exact time i.e. 1 minute, 2 minutes, 3 minutes.
Lastly, during the experiment, tap water was used to measure the change in temperature. However, tap water contains several unknown ions and minerals and every time when the conical flask was refilled with water, the concentration of those ions and minerals may vary. Furthermore, when calculating the heat energy, we used the specific heat capacity used of the water; however, the unknown minerals may affect the specific heat capacity of the
Introduction: In this experiment we determined the difference in accuracy of two different sized cylinders. Accuracy is a measure of how close something is to its true value. To determine the accuracy we had to measure the volume and compare it to the theoretical volume, finding the relative error. Following this we used the density of water, 0.99720 g/mL, along with the mass we determined with a scale, to determine the volume of water in a 10 mL pipet using the formula D=mv.
A calorimeter is an instrument for measuring the heat of a reaction during a well-defined process. There are 2 different types of calorimeters, the first one being what is known as a bomb calorimeter. This is a more advanced calorimeter, it depicts constant volume using the internal energy change between the reactants and the products. This device is more accurate, but also more expensive, so just in case you ever need one but don’t have one of these, there is a simpler, cheaper calorimeter consisting of two foam cups, a thermometer, a glass stirrer and a cork stopper. This one measures constant pressure and the enthalpy change during the reaction. Like I said above, t...
The purpose of this experiment is to use our knowledge from previous experiments to determine the exact concentration of a 0.1M sodium hydroxide solution by titration (Lab Guide pg.141).
Throughout the lab, it was evident that the experiment was inaccurate as numerous errors were observed. Firstly, the entire system was open, allowing the escape of thermal energy. When heating the water on the hot plate, the beaker was not sealed, allowing heat to escape. In the end, when measuring the final temperature of the metals, there was a loss of heat from the styrofoam cup as there was no efficient way of sealing the cup, and the cup itself will also absorb heat from the water. Despite our efforts of sealing the cup by putting another styrofoam cup above, the hole that the thermometer goes through allowed heat to escape. The loss of heat, and the absorption of heat from the styrofoam cup will increase the heat capacities of the metals that were calculated from this experiment. This is due to the fact that the escaped heat and the heat absorbed by the styrofoam cups were calculated as if they were absorbed by the metal, while in reality, they were not. Secondly, numerous assumptions were made. When allowing the metal samples to sit in the cups of room temperature water, it was assumed that over a certain amount of time, the metal would have the same temperature of the water. However, the point at which this occurred was unknown, due to the fact that heat was constantly escaping, which decreased the accuracy of the initial temperature of the metals. Additionally, it was assumed that at some point, the