A series of errors were encountered in doing this experiment. What result would
ID: 507617 • Letter: A
Question
A series of errors were encountered in doing this experiment. What result would each have caused on the calculation of R? Would the value computed be too high, too low, or unaffected? Support your answers with calculations. a. The density and mass percent of the H_2O_2 solution were 1.10g/mL and 4.591% (wt/wt) instead of the 1.01 g/mL and 5.00 % (wt/wt) that you were told. b. The H_2O_2 solution was left out over the weekend in a clear container. You take lab first thing Monday morning and use the concentration written on the bottle in your calculations. Use the ideal Gas Law to support your answer. c. The student read the atmospheric pressure. 30.2 in Hg, off of a second blackboard in the lab that corresponded to yesterday s pressure. Today's atmospheric pressure is actually 759.0mm of Hg. Support with calculations.Explanation / Answer
2. Errors in measurement and its effect on the calculated R value,
a. If the density and the mass percentage used were actually higher than the values mentioned prior to the experiment, the calculated R value would be too low than the theoretical value. The higher the percentage the greater would be the moles of gas produced and thus the R value which is inversely proportional to moles of gas would decrease considerably,
R = PV/nT
with,
n = moles of gas produced.
b. If H2O2 solution was left out, some of it would decompose at room temperature. Thus, now we have lower concentration of it in solution. Moles of gas produced by this would be lower than the actual theoretical value calculated by taking concentration value mentioned on the container. Moles of gas produced would be lower as well in the experiment so, R value would be too high. R is inversely proportional to the moles of gas produced.
c. With actual pressure for the day much lower than the yesterdays pressure, the net pressure of gas calculated would be higher than the actual pressure.
Pressure of gas = atmospheric pressure - vapor pressure of water at that temperature
Thus the R value would be too high as R is directly proportional to pressure.
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.