Question

2. Three students from your lab have to determine a boiling point of an unknown sample that is supposed to be butanone (Bp.-80°C). Although, all three students have conducted their experiment eorrectly, they came up withe different values: 79°C, 84°C and 75°C. a)Explain what could have beon the source of crror if the sample given to the students is a pure sample and student carried out their measurements properly. b) Propose a solution to correct these diverging data if you knew in advance that the sample was butanone (BP-80C 3. A setting apparatus for a distillation includes a thermometer. What it is for? Explain. romet b) What will be the outcome of a distillation without a thermometer? Explain. 4. Define the distribution constant for extraction (ka) by giving the formula used to calculate this constant Kp- 5. A mixture: Acetone (Bp. 62°C) and 2-propanol (Bp. 83°C) has to be distiled. During the distillarion whik compound is collected last? Justify your answer. a) Advantage (fractional distillation) b) Disadvantage (fractional distillation): 10. How is the effectiveness of a distillation changed by each of the following? Explain a) Rapid heating: b) Selecting liquid with identical boiling points: c) Using a long packed column: d) Using a short unpacked column Lcannet read what yow write, I cannot give any poind sece I cannar gwess your thoueh es 3

Answer 1

2. The cause of error may be following

(I) the sample may be contain some non volatile impurities in it due to this the boiling point of the sample will be higher

(II) There may be some error in the caliberation and arrangement of the thermometer that the thermometer may be touch on the bottom surface of the dish instead of holding middle of the smple

(B) The proposed solution may be Propanonone because it is also an aldehyde and have lower boiling point than Butanone . So after mixing of this propanone the resultant boiling point will be adjusted around 80 degree C.