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
Variables --------- During the experiments, the water will be heated using different spirit burners containing different alcohols. I will be able to change different parts of the experiment. These are the. Volume of water heated:
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
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 ...
In experiment’s 2rd trail, a new calorimeter was placed onto the workbench. It was placed onto the electronic scale and weighed 18.600 grams. A thermometer was attached to the calorimeter. The initial temperature was 21.5 C. 50 mL of 1M Hydrochloric Acid was placed into the calorimeter. 0.250 grams of magnesium was placed into the calorimeter. A chemical reaction occurred and the temperature recorded was 43.2 C. The calorimeter was placed onto the electronic scale and weighed to be 68.839 grams. Afterwards, the calorimeter was discarded. In the experiment's third trial, a new calorimeter was placed onto the workbench. It was then placed onto the electronic scale and it weighted 18.600 grams. A thermometer was attached to the calorimeter. The initial temperature recorded was 21.5 C. 50 mL of 1M Hydrochloric Acid was placed into the calorimeter. 0.350 grams were added into the calorimeter. A chemical reaction occurred. The recorded temperature is 51.8 C. The calorimeter was placed onto the electronic scale and the total mass is 68.921 grams. All materials were
The purpose of this experiment is to try to find the original temperature of the hot water in the heater using the 60 degrees C thermometer. Use your 60°C thermometer, and any materials available in your laboratory, to determine the temperature of the water in the coffee pot. During this experiment we calculated the original temperature of a heater after it had been cooled down, and we did this by measuring hot, cold, and warm water, with a thermometer that had tape covering 60 degrees and up. When preformed each of these experiments with each temperature of water, plugging them into the equation (Delta)(Ti – hot – Tf) T Hot x Cp x Mass(Cold) = (Delta)(Tf – Ti – Cold) T Cold x Cp x Mass(Hot)(d
- Temperature was measured after and exact time i.e. 1 minute, 2 minutes, 3 minutes.
In this lab, we found the Heat of Vaporization of liquid nitrogen, supported by the data we obtained. First, we calculated the amount of heat absorbed by the 60.00 g of liquid nitrogen we received. To do so, we had to add the liquid nitrogen to a Styrofoam cup containing hot water at 54.3 °C. We took the temperature of the water and nitrogen until it got to its lowest point, 20.2 °C. The water decreased by 31.5 °C after the liquid nitrogen vaporized. The mass decreased as well. After, we found the amount of heat the cup and water released to be 11,400 J, and the measured heat of vaporization to be 191 J/g or 45.6 cals./g. After, we compared this new heat of vaporization with the theoretical value of 199.9 J/g and attained a low negative percent error of -4.5%.
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.
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.
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...
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
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
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.
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.