Experiment 13.1 Purpose: To determine the ∆H of a chemical reaction. Materials: 2 Styrofoam cups, Thermometer, Vinegar, Mass Scale, Measuring tablespoon and ½ teaspoon, Lye, and Safety goggles. Question: Can you determine the ∆H of a chemical reaction? Hypothesis: The ∆H of a chemical reaction can be found through experimentation. Background: The ∆H is the amount of H (Enthalpy: the energy stored in a substance) that has changed from the initial to the final. There are equations that can determine the ∆H. Procedure: Measure 10 tablespoons of lye, and divide the mass by 30. The quotient will be the mass of 1 teaspoon of lye. Now divide the mass of 1 teaspoon of lye by 2 to get ½. Combine the two Styrofoam cups together to make a makeshift calorimeter. Pour 100.0 ml of …show more content…
Read the temperature every 30 seconds, stop when the temperature stays constant for 2 consecutive readings. Now use the equation (q = m × c × ∆T) to obtain the amount of heat transferred. Ignore the calorimeter. The specific heat (c) of vinegar is 4.1 J/g × C. The mass of the vinegar (m) will be the volume (100.0 ml) times the density (0.99 g/ml), and add the mass of ½ teaspoon of lye. Subtract the initial temperature from the final temperature to get ∆T. Now using these numbers, use the equation above to solve for q. This will also be the ∆H of the reaction. However, now you must take the mass of lye and divide it by the molar mass of NaOH to obtain the number of moles. Now divide the ∆H by the number of moles to get ∆H J/moles. Finally, clean everything up. Discussion: The mass of the lye was taken twice, and the mass of half a teaspoon of lye is 3.3 grams, as 1 teaspoon of lye was 6.6 grams. The initial temperature of the vinegar was 16.0° C. For the first trial, the final temperature was 31.0°C, meaning the ∆T was 15.0°C. The final temperature for the second trial was 33.5°C, which indicates that the ∆T was 17.5°C. The mass of the vinegar was 99
Question3: Experiment 3 The unknown acid sample was 1 • Monoprotic Acid Trails Initial NaOH solution (mL) final NaOH solution (mL) The volume of NaOH to titrate the acid (mL) Amount of Unknown Acid sample 1 (g) The moles of the Unknown Acid (mol) Molar mass of the Unknown Acid (g/mol) A 3.38 28.31 24.93 0.150 0.0026 57.69 B 0.18 29.32 29.14 0.175 0.0029
After the water temperature began to stabilize, the highest constant temperature was recorded. This data was used to calculate the calorimeter constant. This enter procedure was repeated to calculate another calorimeter constant in order to find the average of both answers. After that value was calculated, a 600 mL beaker was filled with 300 mL of water and heated till it started boiling. An unknown metal located on the instructor's bench was obtained and the mass was calculated.
Conclusion: Compare Trial 1 and Trial 2. The Trial 1 change in mass are 12.5g, however Trial 2 changes in mass is 1.2g. The Trial 1 change in mass is more than Trial 2. And I think the Low of Conservation of Mass violated in the Trial 1 is can be exist. Because the Trial 1 actually the soda with vinegar have Chemical reactions occur and chemical
Use the following data to find the energy change in J of each system Specific heat of ice= 2.03 J/gC Specific heat of steam= 1.99 J/gC Specific heat of water= 4.18
I. Title: Mass and Mole Relationships in a Chemical Reaction II. Background: Percent yield is the ratio of actual yield to theoretical yield. Amount in percent of one product formed in chemical reaction. Actual yield is the information found is experiments or is given.
Materials: The materials that I will be utilizing during these experimentations are three to four ice cubes, one cup for measuring, six unblemished cups, one stopwatch, one hot water source, three tablets of Alka-Seltzer, one thermometer that measures from negative
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.
To determine the rate of reaction there are many method to be used for example, measuring the mass after the product has been added and measuring the difference in mass on the duration of a digital scale. Another method, which will be used in this experiment is using a gas syringe to measure the volume of the gas which has been produced. The cylinder inside, will be pushed out to show a quantitative presentation of the volume produced by the reaction. Hypothesis
A scale of zero to five was used to describe the reactions, with zero being no reaction at all, one being a slow reaction, and five being a very fast reaction. The materials used were a test tube rack, six test tubes, a test tube clamp, forceps, a graduated cylinder, four small pieces of liver, one piece of potato, one piece of hamburger meat, approximately forty milliliters of hydrogen peroxide in a forty milliliter beaker, a splint, and matches. An ice bath and boiling water was required for testing, where a hot plate was used to boil the water. Each test tube given a label, which were “cold”, “room”, “hot”, “warm”, “potato”, “meat”, and
In this experiment, the principle of conservation of energy was used and the first equation was as follows: ∑∆Q = 0. Similarly, ∆Q = mLf. Therefore, ∆Qc + ∆Qw + ∆Q ice + ∆Qi →(l) + ∆Q m ice
Materials 1 calibrated thermometer, 1 scale that reads mass, 2 Styrofoam cups, 1 small lead sinker, boiling water in a beaker, 1 pair of kitchen tongs, 1 small cooking pot, stove top, distilled water, and 1 pair of safety goggles (I did not use a cork stopper). III. Procedure First, the beaker
Commercial vinegar, Yamaha brand 0.1 mol/dm3, NaOH soloution Phenolpthalein indicator soloution (50.00 ± 0.5 cm3 ) cm3 burrete (250.00 ± 0.5 cm3) volumetric flask a (250 cm3± 0.5 cm3)
Acids are proton donors in chemical reactions which increase the number of hydrogen ions in a solution while bases are proton acceptors in reactions which reduce the number of hydrogen ions in a solution. Therefore, an acidic solution has more hydrogen ions than a basic solution; and basic solution has more hydroxide ions than an acidic solution. Acid substances taste sour. They have a pH lower than 7 and turns blue litmus paper into red. Meanwhile, bases are slippery and taste bitter.
℃^(-1)×6.40℃±3.1 %=1337.6 J±4.06 % ∆H=(-1337.6 J±4.06 %) /(0.025 mol ±0.16 %)= -53504 J m〖ol〗^(-1)±4.22 % ∆H=-53504 J m〖ol〗^(-1)±4.22 %÷1000=-54 kJ m〖ol〗^(-1)±4.22 % Conclusion and
The mass of vinegar used during the experiment was 4.108 grams. It was determined that there were .003129 moles of CH3COOH in the vinegar sample. Using this information and the molar mass of CH3COOH, which was 60.05 g/mol, the mass of acetic acid in the vinegar was calculated: 4.Vinegar is a 5% aqueous solution of acetic acid. Since the mass of acetic acid within the vinegar was calculated as .18789 g in step 3, the percent of CH3COOH was calculated using the following equation: To calculate the percent error, the experimental value of 4.5% acetic acid in vinegar was subtracted by the theoretical value of 5% and divided by 5% to yield a percent error of 8.54%. The following is a copy of the calculations done using decimals: 5.The equivalence point of the titration curve measured in step 1 was 25.25 mL of NaOH.