Answer:
The same instrument must be used to measure the unknown solution as was used to measure the known (standard) solutions that were used to create the calibration curve.
The analyte in the unknown solution must be the same analyte (or type of analyte) that is present in the known (standard) solutions that were used to create the calibration curve.
Domain and range restrictions must be observed.
Explanation:
Calibration curves are tools necessary in understanding the instrumental response for any analyte.
A calibration curve is obtained by preparing a set of standard solutions with known concentrations of the analyte. The instrument response for each concentration is measured and plotted against the concentration of the standard solution. The linear portion of this plot may be used to determine the unknown concentration of a sample of the analyte.
The equation of the best-fit line is used to determine the concentration of the unknown sample.
Answer:
Explanation:
We are given the percent composition: 22.5% phosphorus and 77.5% chlorine.
We can assume there are 100 grams of this compound. We choose 100 because we can simply use the percentages as the masses.
Next, convert these masses to moles, using the molar masses found on the Periodic Table.
- P: 30.974 g/mol
- Cl: 35.45 g/mol
Use the molar masses as ratios and multiply by the number of grams.
Divide both of the moles by the smallest number of moles to find the mole ratio.
The mole ratio is about 1 P: 3 Cl, so the empirical formula is written as:<u> PCl₃</u>