Alic Albright, Josh Coleman, Dan Boden, Zach Babin
Purpose:
The pupose of this lab was to make an experimental determination of a molar volume through reaction of the substance shown: Mg(s) + 2HCl(aq) > MgCl(aq) + H(g)
Introduction:
In this lab, a magnesium ribbon and HCl are combined in a gas measuring tube. When they are combined they form magnesium chloride and Hydrogen gas. The molar ratio between Mg reacted and H2 produced a 1:1. Thus the number of moles of H2 can be determined if the number of moles of Mg is found. The experimental volume of H2 is found in the experiment and by using the gas laws of both Boyle and Charles. The volume of H2 can be determined …show more content…
T2=273.15° K
(718.12mm Hg x .04712)/(297.15° K)=(760mm Hg)V2/(273.15° K)
(273.15° K/760mm Hg)((718.12 mm Hg x .0471 L)/297.15° K)=((760mm Hg)V2/273.15° K) (273.15° K/ 760mm Hg)= .0409L
V2= .0409 L
The moles of hydrogen gas produced can be calculated using the original mass of the magnesium and the stoichiometric relationships between magnesium and hydrogen.
4.2 cm Mg(1m/100cm)(1.049g/1m)(mol/24.305g)(1 H2/1 Mg)= .0018 mol H2
The following is the STP volume of gas in L/mol
(.0409L H2/.0018 mol H2)=22.7 L/mol
The volume obtained in the experiment, 22.7 L/mol, had a .3 difference from the accepted value of 22.4 L/mol.
The percent error can be found using the equation:
[(theoretical-experimental)/(theorectical)] x 100%
[(22.4-22.7)/(22.4)] x 100% = 1.339%
Conclusion:
The purpose of this lab was to make an experimental determination of molar volume. The molar volume is found by using a form of the equation PV=nRT. The first set of pressure, volume, and temperature are found throughout the experiment. The second set of pressure and volume are the STP. The molar volume obtained is 22.7 L/mol. The accepted molar volume is actually 22.4 L/mol. This gives the experiment a percent error of 1.339%. Experimental error could be that either excess or not enough HCl was used. This could be a reason for the .3 difference in the molar volume obtained in the experiment and the accepted