105a postlab1

Data Trial 1: pipet density = sample + beaker − beaker volume Density for 2% NaCl: 85.4 − 80.2 5.2 = 1 g / cm 3 Average density for water: 1.234 + 0.8 + 0.966 + 1.126 4 = 1.0315 Standard deviation for DI density: √ ( 1.234 − 1.0315 ) 2 +( 0.8 − 1.0315 ) 2 +( 0.966 − 1.0315 ) 2 +( 1.126 − 1.0315 ) 2 4 = 0.1895776 %error(accuracy) for water= ¿ averagevalue − truevalue ∨ ¿ truevalue ¿ ×100% = 1.0315 − 1 1 ×100%=3.15% Trial2: buret

Average DI water density: 0.9955g/cm3 Standard deviation for water density: 0.0198 %error(accuracy) for water= ¿ averagevalue − truevalue ∨ ¿ truevalue ¿ ×100% = 1 − 0.9955 1 ×100%=0.45% Percent error in buret trial is smaller, so buret is more accurate than pipet. Graph Trial 1 Linest equation