Using Stoichiometry to Determine Gases Produced Essay Example

the ribbon. 3. using stoichiometry and the ideal gas law, calculate the mass of magnesium metal needed to collect exactly 40 mL of H2 gas from the reaction given.

Make sure to use current temperature and local barometric pressure.

4. Calculate the length of magnesium ribbon using the mass you found in step 3. 5. Cut the length needed of magnesium ribbon. 6.

Obtain about 25 cm of copper wire and wrap it around the magnesium ribbon. Be sure that you wrap the copper wire around the ribbon tightly. 7. Pour 15 mL of 6M HCI into the gas collecting tube and record the exact volume.

Make sure to tilt the tube and pour the HCI In very slowly. "These next few steps are to be done quickly, the water so that the "tail" is outside of the tube. 9.

Fit the stopper into the tube so that the copper cage is fixed in place. 10. Fill the stopper hole with water using Dl squirt bottle.

11. Put a finger (gloved) over the hole and invert the tube, place the tube into the beaker filled with water and remove your finger. 12. When the reaction has stopped, raise your tube out of the water until the height of the water is inside the tube is the same as the height of the water in the beaker. 13. Record the volume of the gas inside the tube.

14. Find and rerecord the temperature of the water in the beaker and the temperature of the air in the room.

Results "hen we did our experiment, we put the magnesium strip into the beaker and saw the reaction

occur. As the magnesium was reacting with the hydrochloric acid the Naves were going up and the pressure of the reaction was pushing the air to the top of the tube. The pressure of the air was .

997 atm, and the temperature was 293. 15 K. "hen we calculated the mass, length and volume of the magnesium ribbon, we made sure to record all the data to make sure if we ever needed it again for another experiment we would have the measurements. You can find the measurements in fgure 1.

Figure 1) Data from Experiment Done with Magnesium and Hydrochloric Acid Mass of Mg needed to produce 40 mL H2 Length of Mg ribbon needed to produce 40 mL of H2 Exact mass of Mg ribbon cut and used in reaction Exact volume of 6M HCI Volume of gas produced Nater temp. Room temp.

040 g Mg 4. 4 cm . 04 g 15. 0 mL 39 mL 17 degrees C 20 degrees C Having these results will help us determine where we need to be if we ever do this lab ever again.

We worked in pairs for this experiment so it made it easy to do all the steps really easily. We calculated the mass of the magnesium to produce 40 mL of hydrogen and got . 0 grams of magnesium. Then we took that and got the length of the magnesium ribbon and came up with 4. 4 centimeters.

When we took the weight of the magnesium ribbon, it came out to be exactly . 4 grams. The procedure in the lab stated we needed 15mL of 6M of HCL.

So we didn't really calculate anything for this data, it was given in the lab. To get the water and room temperature, we took a thermometer and measured it as well as recorded it.

Discussion and Conclusion By working on this lab, we learned how to measure the amounts of gas produced after a certain reaction occurred in a test tube.

When this occurred, some of the gas had been pushed out from the bottom of the test tube into the water. When the n the test tube as well as the graduated cylinder. Doing this, would give us a more accurate measurement because of the pressure of the water in both containers Nould make one another be less dense or more dense. If the test tube was pushed pass the level of the water the volume of the gas inside the tube would be denser because you are putting more pressure on the tube for it to stay up. When you lift the test tube above the water it will be less dense because the volume will have less ressure on it.

The reason for doing all of this was to get the closest measurement to the atmospheric pressure, which was . 997 atm. When the gas is released into the tube, water vapor is collected at the end of the tube, which in turn alters our results. This shows the definition of partial pressure of Dalton's Law.

He states that the mixture of gasses equals the sum of the pressures that exert if it were present alone. To eliminate water vapor we have to subtract pressure total from pressure of the water vapor

to find the pressure of the hydrogen gas by itself.

Our lab was successful except for one error; when we put the magnesium into the test tube and put the stopper on, we put the magnesium where the spout was on the test tube, which made some of the magnesium, react with the acid. This was a problem because we were supposed to have 40 mL of gas produced but since the magnesium did not react fully, we could only produce 39 mL. Something that could be an improvement on the lab could be when measuring the magnesium, instead of cleaning off the magnesium with wool it could already be cleaned.

This could reduce the time of the lab.