here is the procedure of my experiment of finding gas law constant..and here are
ID: 1087450 • Letter: H
Question
here is the procedure of my experiment of finding gas law constant..and here are my calculations
and i need to give answers to these questions
PROCEDURE 1. Calculate the mass of magnesium necessary to evolve 80 ml of H2 al STP. Then weigh approximately this quanüty of Mg ribbon on the top-loading balance to the nearest mg (30.001 g). ood add approximately 8 mL of concentrated HCl to a eudiometer tube. With your wash.bottle, wash down into the tube any acid that might have adhered to the eudiometer walls. Coil the weigbed stip of Mg ribbon into the cudiormete opper wire wrapped around the ribbon helps to keep it in place.) Fill the tube with water and invert into a suitable vessel nearly filled with water. The eudiometer volume should read zero if the tube is filled completely r tube, approximately 5 to 10 cm from the open end. (C with water. Record the initial reading in your laboratory notebook. Clamp the tube in pesition (Figure 10-1). 3· Th e concentrated HCl will gradually diffuse down to the Mg and react with it. The Mg may break free rom the copper wire. Til the tube to ensure that the Mg does not stick to the sides of the tube. After reacüon has ceased, if possible, adjust the liquid level in the tube to the level of liquid in the vessel. The gas pressure in the tube is then equai to almospheric pressure. if the difference in levcls is large, it must be measured as shown in Figure 10-1. Record the temperature of the water in the vessel at 1-min intervals for 3 min. Take the average value as your gas temperature 4. S. Repeat the experiment for a total of four determinatons 6C nd re Mass of Mg(g) 24.31 g/mol Number of moles of Mg. , =-24.31 g 7. Calculate the corrected pressure for the experiment as described above using the observed barometric pressure for the day.Explanation / Answer
1.
The biggest source of error when you work with gases, usually is avoiding the gas to escape. When you have a gas leak, the ammount of gas loose is big even if the leak is really small, also if you do not get equal pressure in your test tube and in the edimeter, you will have an error in your calculations.
2)
a)
An air bubble was trapped in the eudiometer once it is being inverted in the beaker.
This would mean that you would start with an existing volume of gas present in the system (V(initial) ? 0), so your final volume would be greater than the theoretical value.
Because R is directly proportional to V, the calculated value of R would be greater than the true value.
b)
Some Mg adheres to the inside wall of the audiometer tube after the reaction has ceases and the acid level is quite a bit lower than the piece of Mg
This would mean that you did not react all of the magnesium, so the volume of gas produced would be less than the theoretical value. Because R is directly proportional to V, the calculated value of R would be less than the true value.
c)
Some H2 escapes into the beaker during the reaction.
so R will decrease because PV=NRT
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.