There are directions in the Procedure, which if not followed as written, would i
ID: 956591 • Letter: T
Question
There are directions in the Procedure, which if not followed as written, would introduce errors. Consider the deviations below, and comment on how a student's results would be affected. A student allowed all the water in the beaker to boil away, but continued the experiment (refer to steps 3 and 7). Another student was in a hurry and stopped heating, even though bubbles were still emerging from the rubber tubing (refer to step 8). A student used the measure of Flask no. 1 to be 250 mL, without measuring the volume as directed ret ted (refer to step 11). A student recorded the temperature in degrees Celsius and used these values in the calculations (refer to Report Sheet no. 1, no. 3, and no. 8).Explanation / Answer
1.) Unless it is being heated by the boiling water, we have no idea what temperature the gas is at.
It might actually be cooler that 100C, if the flask was heated in a large beaker
and the water had evaporated off
had the flask been heated by the flame directly, I would expect its gas to be hotter than 100C
2.)If another student was in a hurry and stopped heating, even though bubbles were still emerging from the rubber tubing, the whole is not tranfered to the other flask, then the volume used in the caluclation will less than the actual volume that should be used in the calculation and would give wrong results. When bubbles emerge no longer from the rubber tubing, the only the flask must be lifted and placed into the iced water bath
3.) a 250 Erlenmeyer flask holds 250 mls at about the point where the sides become vertical. filled to the brim, it is actually about a 270 ml flask
as the temp changes in degrees Kelvin, we expect that the volume of the gas will change by the same percentage.. so if we cooled it 30% we expect that the volume will drop 30%
so that V1/T1 = V2/T2
but if we expected it to drop 30 % of 250 ml, i.e. by 75ml
we would find that the volume actually droped by about 80 mls , which is 30% of the actuall volume
so that V1/T1 would not equal V2/T2
4.) Charles law :This equation expresses pressure in atmospheres, volume in liters, temperature in degrees Kelvin, and the quantity of gas in moles. These four quantities are related exactly through the use of the ideal gas constant, R; the value for R is 0.0821 L atm/K mole. (Notice that the units for R are in terms of V, P, T, and n.)
V = K . T
charles law
The temperature would be less as in K = 273 L C, so the temperature would be less by 273 K and it would give wrong results due to wrong calculation value
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