1) A and B react according to the scheme 2A + B → C. The reaction is highly exergonic, that is, it goes to completion when A and B are allowed to react. 2.000 tons of A and 1.00 ton of B were mixed in a kettle. A balance, the maximum capacity of which is 0.500 tons with 1% precision was used to weigh A and B. Assume that the molar masses of all chemical species are equal. What is the maximum possible amount of unreacted reactants?
2) An experiment is performed to determine the force constant k of a spring by measuring its length as a function of the applied load. The following data are obtained:
|
Mass (g)
|
Length (cm)
|
|
Mass (g)
|
Length (cm)
|
|
10.0
|
5.1
|
|
110.0
|
36.57
|
|
20.0
|
8.8
|
|
120.0
|
38.57
|
|
30.0
|
10.9
|
|
130.0
|
43.55
|
|
40.0
|
14.3
|
|
140.0
|
46.88
|
|
50.0
|
18.0
|
|
150.0
|
49.01
|
|
60.0
|
20.56
|
|
160.0
|
52.20
|
|
70.0
|
23.94
|
|
170.0
|
54.19
|
|
80.0
|
26.94
|
|
180.0
|
58.52
|
|
90.0
|
30.92
|
|
190.0
|
61.84
|
|
100.0
|
33.91
|
|
200.0
|
64.50
|
Report the values of L0 (initial length) and k (force constant) and their associated uncertainties with 95% confidence limit.
3) Each student measured the lengths of a pencil using calipers. Record and combine your data into one table. Calculate the average value for the length of the pencil. Calculate the standard deviation.
4) From the data below calculate the viscometer constant for 716L viscometer (the viscometer constant is the hypothetical time required for water to flow through viscometer capillary). Water was used to calibrate 100 viscometer, which was in turn used to find the viscosity of liquid 1. Then, liquid 1 was used to calibrate 200 viscometer, which was used to determine the viscosity of liquid 2, and so forth. Use the equation η1/η2 = t1/t2 for the calculations.