A volatile liquid can be easily converted to its gaseous state, the gas that forms from vaporization is known as vapor and it is assumed to behave as an ideal gas. One of the properties that characterize a volatile liquid is determination of its molar mass. Dumas method also known as the vapor density method uses the vapor density of the unknown volatile liquid in determining its molar mass. The major assumptions of these methods are the substance behaves ideally. The molar mass of a volatile liquid can be obtained by measuring the temperature, pressure, mass, and volume in a gaseous state. The equation used to determine the molar mass is derived from the Ideal Gas Law equation. The objective of this experiment aims to determine the molecular mass of a …show more content…
In order to calculate for the molar mass the temperature, volume, mass, and pressure was measured. The ideal gas law equation was derived in order to express the relationship between the molar mass, mass of the condensate, temperature, pressure, and volume. A 125-mL Erlenmeyer flask was added with an unknown liquid, was capped with an aluminum foil with a tiny hole and was heated in boiling water in a beaker until the liquid in the flask is vaporized. The flask was cooled until condensate is observed. After cooling, the flask was weighed in an analytical balance. The experimental molar mass was 45.56g, which is closely identical to the 46.068g of the molar mass of ethanol. The percent error between the two values is 1.10%, the probable sources of error are the following: the size of the tiny hole in the aluminum foil, measurement of the temperature in the thermometer, and measurement of the initial volume of the flask. The recommendation for the experiment is to dry the flask completely before measuring the initial mass and to closely observe if the temperature of the water bath is
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.
The hypothesis made, the density calculated in the experiment will stay the same because the density of the unidentified object will never change, was supported. The results support the hypothesis because in every trial the density always came out to 9g/mL. In trial one the mass was 71.16g, the volume was 8mL, and the density was 8.895g/mL, but when rounded to the proper sig fig came out to 9g/mL. In trial two the mass was 71.12g, the volume was 8mL, and the density was 8.89g/mL, but when rounded to the proper sig fig came out to 9g/mL. In trial three the mass was 71.14g, the volume was 8mL, and the density was 8.8925g/mL, but when rounded to the proper sig fig came out to 9g/mL. When averaged the mass was 71.14g, the volume was 8mL, and the density was 9g/mL. Errors that could have occurred are, not calculating the density correctly, not completely submerging the unidentified object with water in the graduated cylinder to get the volume, not rounding the sig figs correctly when finding the density, not measuring the unidentified object’s mass in grams, not measuring the unidentified object’s volume in milliliters, and not writing the correct units with the proper number or not the correct unit at all.
Characteristic Property- Test 2- Density Materials: Triple Beam balance, distilled water, graduated cylinder, unknown 6 Procedure: first we found the mass of the empty graduated cylinder and then its mass with the now distilled unknown. After subtracting the mass of the graduated cylinder, we were able to find the volume. For every 1mL=1cm³ so there we had the volume found with the graduated cylinder. We divided the mass by the volume in order to get the density Data: We found that the density of our unknown was 0.76 g/cm3.
In the lab “All That Glitters” the objective that was focused on during the lab was calculating the density, volume and mass of various substances. The method that was used in finding the volume of the samples is called the displacement method. This is a process where the volume of the water in the graduated cylinder is calculated before and after the sample is placed. In this lab, the goal of the experiment was to identify and come to consensus about what the unknown substance might be. For this experiment, the required materials were ten pre and post pennies, unknown sample, graduated cylinder, weigh boat, water, paper towels and a weighing scale.
Using the equation m = ΔTf/Kf , the molality of the unknown solution was found. Then, moles of unknown were calculated, which was used to calculate the average molar mass of unknown. Theory: After the experiment was completed, the data
I. Purpose: To experimentally determine the mass and the mole content of a measured sample. II. Materials: The materials used in this experiment a 50-mL beaker, 12 samples, a balance and paper towels. III.
CONCLUSION As can be seen from the graph above, the mass percentage difference decreases as molarity increases. In other words, the molarity and the mass percentage difference are inversely proportional. According to figure 2, the mass of the trial 1 potato which will be submerged in the sugar solution with a molarity of 0.0, is 0.49 grams. The same potato piece after being soaked for 24 hours in the sugar solution of molarity 0.0, is 0.69 grams.
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.
The topic of research is, “how fast does an Alka-Seltzer tablet make gas?”. In the experiment, the scientists will be measuring the chemical reaction rates that occur, when 1 Alka-Seltzer tablet is placed in a specific temperature of water. The independent variable during the experiment will be the temperature of the water (degrees Celsius). The dependent variable during the experiment will be, the rate in which gas is produced (in seconds). The constants of the experiment, will be the amount of water used and the Alka Selter compound.
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
14 vials were used for cotaining samples. When the distillation was proceeding at a moderate speed at about the wanted temperature, the receiver was replaced with a vial as the condensed vapour sample (V) and the thermometer was read. Half of the vial was filled with the sample. The stopper of the distillation flask was removed and using a dropper to collect the liquid.
Each group was assigned a different percent of sucrose solution out of the four variables; 0% , 5%, 10%, and 15%. After we filled the beaker we then got two potato cores. Once we had the cores we cut the skin off the ends. Following this we then cut the two potato cores into four 2.00 cm potato cores. After they were cut into 2.00 cm each we found the mass.
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
Introduction: In this lab, of water in a hydrate, or a substance whose crystalline structure is bound to water molecules by weak bonds, is determined by heating up a small sample of it. By heating, the water of hydration, or bound water, is removed, leaving only what is called an anhydrous compound. Based on the percent water in the hydrate, it can be classified as one of three types: BaCl2O ⋅ 2H20, with a percent water of about 14.57%, CuSO4
Conclusion The GC ethanol analysis method described above has a simple concept, its rapid, and extremely accurate, determining ethanol precisely without interference from other beverage components. With this method, it takes only 7 to 8 min to complete a sample analysis for the determination of ethanol content in a beverage sample. Analyst handling is minimized to prevent deviation in results or possible human error. This method requires a gas chromatograph and a digital integrator, both reasonably expensive and sophisticated pieces of equipment.