CHEM 116 Midterm: CHEM 116 UMass Boston CH116 PracticeExam1 ErrorAnalysis
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Use graham"s law of effusion to identify an unknown gas by comparing its effusion rate to that of a known gas under the same conditions. 44 g/mol speed of fast gas speed slow of gas. M little or speed of fast gas speed slow of gas. Conclusion: first figure out what the question is asking, then conceptualize, then estimate, then do the math. Use various gas laws to calculate predicted values of measurable variables in a gas. Given known values for all initial conditions and all but one final variable, calculate value of unknown final variable. 2 (cid:149) 50% of students used correct equation but forgot to change temperature to kelvin (cid:149) 10% of students did algebra upside down and also did not convert temperature to kelvin. Conclusion: don"t forget to use absolute (kelvin) temperatures in equations. Use the ideal gas law in calculating density. Given p, t and molecular formula, calculate density.
