Lab Report Determining the Molar Volume of a Gas
Introduction:
This lab was designed so that we, the students, could learn how to determine the molar volume of a gas effectively.
Method:
The first step that we took to accomplish our goal was to put on our safety goggles and choose a lab station to work at. We received one 400ml beaker, one polyethylene pipet, two test tubes with hole rubber stoppers, two small pieces of magnesium (Mg), one thermometer and a vial of hydrochloric acid (HCl). We took the 400ml beaker and filled it about 2/3 full of water (H20) that was 18 OC. Then we measured our pieces of Mg at 1.5 cm and determined that their mass was 1.36*10-2 g. We filled the pipet 2/3 full of HCl and poured it into one of the test tubes. Then, we covered the HCl with just enough H2O so that no H2O would be displaced when the stopper was inserted. After inserting the stopper, we placed the Mg strip into the hole, inverted the test tube and placed it in the 400ml beaker. HCl is heavier than H2O, so it floated from the tube, into the bottom of the beaker, reacting with the Mg along the way to produce hydrogen gas (H2). We then measured the volume of the H2, cleaned up our equipment and performed the experiment a second time.
Results:
The formula for reducing the volume of the H2 to STP in trial 1:
P1 V1 = P2 V2 766.0 mm Hg * 14.5ml = 760 mm Hg x
T1 T2 291 K 273 K
X = 13.71 ml
The equation for finding the molar volume in trial 1 with conversion to Liters:
Volume of H2 in STP 13.71 ml * 1L
Moles of Mg used 5.6 * 10-5 moles 1000 ml
Molar Volume in trial 1 = 24.48 L/mole
When the Mg interacted with the HCl, we observed a bubbling reaction.
Discussion:
The molar volume of the H2 in our experiment is very close to the theoretical molar volume, but I think that the deviation lies in the temperature of the H2O: in the first trial it is too high and in the second one too low.
the replicate shows the same trend as the first experiment. I used a measuring cylinder and a beaker to measure out the amounts of water; however these did not seem to affect the quality of my results. To increase the accuracy of my results I could have perhaps used a burette. Even though I did the best I could to keep the experiment accurate, I did. some places there were mistakes that unintentionally occurred.
We began this investigation by suiting up in lab aprons and goggles, we then gathered our materials, found a lab station and got to work. We decided to start with the magnesium in hydrochloric acid first, we measured out 198.5 L of HCl and put it in the foam-cup calorimeter and took initial temperature reading. We then selected a piece of magnesium ribbon and found its mass: 0.01g. This piece was placed in the calorimeter and the lid was shut immediately to prevent heat from escaping. We “swirled” the liquid mixture in the calorimeter to ensure a reaction, and waited for a temperature change. After a few moments, the final temperature was recorded and DT determined.
However, the increased temperature of the new acid solution was at a greater temperature than the ambient temperature and the temperature of the water. This suggests that some of the results obtained were partially due to the fact that some of the heat energy of the acid was transferred to the water, as well as the hydration of ions present in solution. An improvement would be to create the solutions of desired concentration and allow them to reach thermal equilibrium with the surroundings. This would allow more accurate results and the allow for the assumption that the temperature change observed during the experiment would only be due to hydration of
To complete this lab several chemicals must be measured and transferred to test tubes. First 5.0 mL of 0.200 M Fe(NO3)3 must be diluted to a total volume of 50 mL in a flask. Next 0.0020 M SCN–. This solution is then added to 4 test tubes in 1 mm increments. Each test tube is then put in to
Apparatus: * 1 measuring cylinder * 1 test tube * 1 stop clock * A large gelatine cube containing indicator and NaOH * Hydrochloric acid ranging from 1-3 molars * A scalpel Diagram: Method: * Take the large gelatine cube and cut into 15 equal pieces * Place on piece of the cube into the test tube * Measure out 10mls of HCl in the measuring cylinder * Pour the HCl into the test tube with the gelatine cube and start the clock * Time how long it takes for the pink colour inside the gelatine cube to completely disappear * You will also notice that the cube dissolves slightly * Record your results and repeat this same process 3 times for each molar of acid: § 1 molar § 1.5 molar § 2 molar
Also the investigation will be performed in a sensible manner and there is no dangerous behaviour. Prediction When the experiment is taking place I believe that the magnesium in the hydrochloric acid will begin to bubble and then disappear, I also
The Gravimetric Stoichiometry lab was a two-week lab in which we tested one of the fundamental laws of chemistry: the Law of Conservation of Mass. The law states that in chemical reactions, when you start with a set amount of reactant, the product should theoretically have the same mass. This can be hard sometimes because in certain reactions, gases are released and it’s hard to measure the mass of a gas. Some common gases released in chemical reactions include hydrogen, carbon dioxide, oxygen and water vapor. One of the best methods for determining mass in chemistry is gravimetric analysis (Lab Handout).
The Effect of Temperature of Hydrochloric Acid on the Rate of Reaction Between Hydrochloric Acid and Magnesium
Gas Chromatography also known as vapor-phase chromatography (VPC), or gas–liquid partition chromatography (GLPC) is most widely used analytical technique in the world; it is used for the separating and analysing compounds that can be vaporized without decomposing. Among its uses are being able to test the purity of a substance, being able to separate different components in a mixture and help in environmental contaminant identification . This can lead to GC being able to help identify an unknown compounds. The goal purpose of GC is to separate the mixtures into individual components that can be detected and measured one at a time. A plot of the detector output is called a chromatogram, which charts the detector’s response as a function of time, showing the separate components
If there is not enough energy no reaction takes place. In a solution of 0.5M hydrochloric acid, there are less hydrochloric acid particles compared to that of 2M hydrochloric acid, therefore, there are less particles to react with magnesium particles thus meaning less chance of collisions between the two reactants: [IMAGE] Therefore, as the concentration of the hydrochloric acid is increased, the chances of collisions increase thus giving a faster rate of reaction. Apparatus: Beaker Hydrochloric acid Distilled water Measuring cylinder Pipette Test tubes Test tube rack Diagram: [IMAGE] Method: Measure out 10cm3 of hydrochloric acid, as the concentration requires, for each concentration its composition is: Moles Volume HCl Volume Water 2M 10 cm³ 0 cm³ 1.5M 7.5 cm³ 2.5 cm³ 1M 5 cm³ 5 cm³ 0.5M 2.5 cm³ 7.5 cm³ 0M 0 cm³
3 cm of magnesium ribbon generally has a mass of 0.04 g and yields 40 cm3 of hydrogen when reacted with excess acid. 50 cm3 of 1M hydrochloric in this experiment is in excess.
First of all, the purpose of this lab was to determine the water’s vapor pressure at different temperatures as well as to measure the molar heat of vaporization of water using the Clausias Clapeyron equation. The first concept out of many represented in this lab is the ideal gas law. The ideal gas law is used to get the number of moles of air trapped in the 10 mL graduated cylinder. Once we cooled the system so that water vapor is extremely minute, and then we determined the number of moles of air using the ideal gas law. The number of moles of air equals to the pressure (in atm) times volume divided by constant times temperature. One would assume that when the water is heated to 80 degrees, the number of air molecules in the air bubble would decrease, but it actually stays constant. This is due to the fact that there is no air coming in or out of the cylinder. As the temperature gets closer to 80 degrees, the number of air molecules stays the same but the water vapor increases. And the bubble expands to keep the pressure at the same level. The ideal gas law was also used when the partial pressure of air in the gas mixture is calculated. This is gotten from number of moles multiplied by the constant and the constant and the whole thing divided by the volume.
Change of Volume of a Gas Planning- Aim * Determine how the volume of a gas changes with the temperature for a fixed amount of gas and pressure. * Determine absolute zero Hypothesis ---------- Volume is directly proportional to Temperature ---------------------------------------------- Preliminary Test ----------------
tube. Add 6 mL of 0.1M HCl to the first test tube, then 0.1M KMnO4 and
In this experiment three different equations were used and they are the Stoichiometry of Titration Reaction, Converting mL to L, and Calculating the Molarity of NaOH and HCl (Lab Guide pg. 142 and 143).