To calculate the percentage of organic carbon in the soil sample, we need to use the calibration data and the instrument readings for the soil sample.
First, we need to calculate the response factor (RF) using the calibration data. The response factor relates the instrument reading to the actual amount of organic carbon in the sample. It is calculated using the following formula:
RF = (amount of organic carbon in the reference sample) / (instrument reading of the reference sample)
The reference sample used in this case is oxalic acid (COOH)2, and its weight is 0.1005 g, while the instrument reading is 102540.
RF = (0.1005 g) / (102540) = 9.8 x 10^-7 g/instrument reading
Next, we need to determine the amount of organic carbon in the soil sample. We can calculate this using the following formula:
amount of organic carbon in the soil sample = (instrument reading of the soil sample) x RF
For the soil sample, the instrument reading is 14515.
amount of organic carbon in the soil sample = (14515) x (9.8 x 10^-7 g/instrument reading) = 0.0142 g
Finally, we can calculate the percentage of organic carbon in the soil sample using the following formula:
percentage of organic carbon = (amount of organic carbon in the soil sample / weight of the soil sample) x 100
The weight of the soil sample is given as 0.1115 g.
percentage of organic carbon = (0.0142 g / 0.1115 g) x 100 = 12.75%
Therefore, the soil sample contains approximately 12.75% organic carbon.