Tips for chem test 1

Tips for chem test 1 - -unbalanced net force up-F bolts +ma...

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Tips: -Force + weight=buoyant force (F +mg object = mg displaced liquid ) m=V*p -For g c divide by 32.32(slug) when using ft/s 2 or any American units (usually for force or energy calcs) -Error: random, systematic(poor accuracy), absolute blunder -Precision: low STD & Accuracy: Average is close to real value, but high STD - additivity of volumes: (m1/m)/p1 + (m2/m)/p2=(1/p) or m1/p1 + m2/p2=m/p -x1/p1 + x2/p2 = 1/p (mass fractions) -flow rates (p=m/v= m rate /v rate ) -rates usually have dot on them -Composition: convert grams to moles(or use given mole percent) and multiply by MW of each atom - air is 21 mol % oxygen and 79 mol % nitrogen -concentration: molarity=mols solute/liters solution -Manometer equations:p2gd2 + pfgh + P2 = P1 + p1gd1 or pressure drop: -pressures in a container: atm force on it, bolt force, weight (all down) & gas is only force up
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Unformatted text preview: -unbalanced net force up-F bolts +ma net upward force=(pi)r^2(p)-Force up from gas=force of weight, bolt, and atm (if nothing is happening)-process classification: batch or semi-batch (both with chem. rXns) or continuous-normally steady state-Residence time: RsT=(Vm 3) /(V rate m 3 /s) or v/V rate is reasonance time-gen mat bal: (input-output) + (production-consumptio) +accumulation-not pro/consum only for chem. Rxns and accumulation only for steady steady-MAT BALANCES:-draw pics and write down all info always!!!-Examples:-Find V in 1 st order reaction (A to B) given concentrations of A in and out, flow rate of A(same for in and out), and given rate constant conc in (flowrate)=conc out (flowrate) + rateconstant(conc out )(volume) -...
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This note was uploaded on 04/06/2008 for the course CHE 2114 taught by Professor Pldurrill during the Spring '08 term at Virginia Tech.

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