37. Solving a chemistry problem

1 A sample of an organic compound with a mass m (g) was burned in a stream of oxygen. Water was frozen out in the gaseous products of pyrolysis, and carbon dioxide was passed into a cell for measuring electrical conductivity containing a solution of Ba(OH)2. The resistance of the solution in the cell before and after the experiment changed by ΔRx. Standard substances containing from 200 to 1000 μg of carbon were burned under similar conditions, and the ΔR value was also measured for each sample. The measurement results are shown below:
mC in the sample, µg 200 400 600 800 1000
ΔR •10-6, Ohm 80 150 220 285 355
Construct a calibration graph and calculate the mass fraction (%) of carbon in an organic compound using the following data:
m, mg 0.9982
ΔR •10-6, Ohm 115