# Evaluation of a Gas Law Constant Lab

Topics: Pressure, Gas, Ideal gas law Pages: 3 (703 words) Published: March 2, 2013
Title: PROP0332 Evaluation of the Gas Law Constant

Abstract: The result of the change in volume was approximately 22 CC or 0.00084 mol. This translates into the average for the R constant being 83.8L*atm/K*mol. The four determinations ensured that the results were accurate because more than one trial helps somewhat prevent error. Approximately 0.20g of the Mg ribbon was used for these determinations.

Introduction:
1. Theory
If the temperature of a gas sample was held constant, its volume varied inversely with its pressure. The Kelvin scale is known as the absolute scale. Charles’ law states that volume of a given mass varies directly with its absolute temperature if the pressure remains constant. Ideal gases are those whose behavior is exactly described by Boyle’s and Charles’ laws. Avagadro’s principle says that the volume of a gas sample at a given temperature and pressure is proportional to the mass or number of moles of the gas. 2. Reference citations

Grover W. Everett, East Carolina University, Signature Lab Series, Prop 0332, p. 141 3. Important Equations
V α 1/P
V=K1/P
V=K2*T
V α T
P1V1T1P2VxT1P2V2T2
Vx=V1(P1/P2)
V2=Vx(T2/T1)
V2=V1(P1*T1/P2*T2)
P2*V2/T2=P1*V1/T1
PV/T=K
PV=nRT
Mg(s)+2HCl(aq)MgCl2(aq)+H2(g)
PV/nT=R
PV/nT=atmosphere-millileter/mole-degree=R
Corrected pressure, atm= ((recorded barometric pressure, torr - vapor pressure of water, torr)/760 torr atm^-1)

4. Objective
In the experiment, one must determine the volume of a known mass of a gas at a measured temperature and pressure. One must use data to evaluate the universal gas law constant, R.

Experimental:
1. The procedure for this experiment appears in the lab manual1. Everett, G.W.; Everett G.W. Jr. Classifying Matter by Properties; Cengage Learning: Manson, OH, 1997, pp 143-149. Results:
Mass Mg, g0.021g0.021g0.022g0.020g
# of moles Mg
Initial syringe vol, mL4.5 CC5.0 CC19.0 CC10.0 CC
Final syrine vol, mL26.5 CC27.3 CC43.3 CC...