CHE 131 Lecture Notes - Lecture 15: Molar Volume, Molar Mass, Mole Fraction

Name: Date: Partners DATA TABLE Trial 1 Trial 2 lay:ial95m '직 Mass of test tube, rubber band and fo cover (g) Temperature of water bath (°C) Mass of test tube and foil and condensed gas sample (g) Mass of the condensed gas sample (g) Barometric pressure (mmHg) Volume of the test tube (mL) Molar mass of the unknown sample (g/mole) 113过140 Average molar mass (g/mol): DATA ANALYSIS (Show your calculations) 1. Determine the mass of the condensed portion of the unknown that you placed in the test tube. 2. Use the equation 4, along with the recorded temperature of the boiling water bath and the barometric pressure of the room, to calculate the molar mass of your unknown compound The molar mass of the unknown sample can be calculated using the ideal gas law: PV=nRT (Equation 1) P = pressure (mmHg) V = volume (mL) n = number of moles mL. xmm Hg ideal gas constant molx K The number of moles, n, is the mass, in g, divided by the molar mass (M): n =-m(g) Equation 2) M (g/mol)

Molar Volume of a Gas Room temperature (T,): 23.4a Barometric pressure: 6s torr 23. "c Trial 2 Trial 3 Trial 1 0,012 9048 007b Mass of Mg strip Temperature of water in the 600-mL beaker Vapor pressure of water at the temperature 22.(4 o2oborr 1032t torr in the 600-mL beaker Volume of gas collected at room temperature Volume of gas in liters (V) Partial pressure of hydrogen gas at room Partial pressure of hyd Volume of hydrogen gas at STP torr torr torr 761.5 temperature rogen gas in atm (P) atm atm atm L. PSTpVSTP, TSTP (solve for Vsrr) P,v, T2 = Moles of hydrogen produced based on amount Molar volume of hydrogen (L/mol) at STP Average molar volume of hydrogen mol mol of Mg used (use balanced equation) L/mol L/mol L/mol (calculated from your data) L/mol Molar volume of an ideal gas at STP L/mol Percent error