Determination of Copper Oxide's Percentage Composition and Empirical Formula - Prof. Patri, Lab Reports of Chemistry

Download Determination of Copper Oxide's Percentage Composition and Empirical Formula - Prof. Patri and more Lab Reports Chemistry in PDF only on Docsity! Date Performed:9/30/09 Name: Dillan Date Submitted:10/07/09 Partner: Instructor: Zhang Yafen Determination of a Chemical Formula Objective To determine the percentage composition and the simplest formula for an oxide of copper by its reduction with CH 4 at approximately 500°C Experimental Data Mass of test tube = 17.52g ± 0.01g Mass of test tube+Cu oxide = 19.81g ± 0.01g Mass of test tube+Cu = 19.35g ± 0.01g Sample Calculations Mass of Cu oxide: 19.81g ± 0.01g - 17.52g ± 0.01g = 2.29g ± 0.01g Uncertainty: S=√Sa 2 +Sb 2 S=√0 .012+0.012 S=0.01 Mass of Copper: 19.35 ± .01 - 17.52g ±.01 = 1.83g ± 0.01g Uncertainty: S=√Sa 2 +Sb 2 S=√0.012+0 .012 S=0.01 Mass % of Cu: 1.83±0.01 2.29±0.01 ×100=79.9 %± .6 % Uncertainty: ( SrR ) 2 =( SaA ) 2 +( SbB ) 2 ( Sr79.9 ) 2 =( 0.011.83 ) 2 +( 0.012.29 ) 2 Sr=79.9√.000049 Sr=.6 Mass of Oxygen: 19.81g ± 0.01g - 19.35g ± 0.01g = .460g ± 0.01g Uncertainty: S=√Sa 2 +Sb 2 S=√0 .012+0.012 S=0.01 Mass % of oxygen: .460±0.01 2.29±0.01 ×100=20.1 %± .004 % Uncertainty: ( SrR ) 2 =( SaA ) 2 +( SbB ) 2 ( Sr.201 ) 2 =( .01.460 ) 2 +( .012.29 ) 2 ( Sr.201 ) 2 =( .01.460 ) 2 +( .012.29 ) 2 Sr=.004 Moles Cu = Mass ofCu MollarMass of Cu 1.83 g±0.01 g 63.55g /mol±.01 g/mol =.0288mol± .0002mol Moles O= Mass ofO MollarMass of O .460g±0.01g 16.0 g mol ± .01g /mol =.029mol± .0006mol