I just someone to check my work, i have already done all of them but there is missing stuff i didn’t solve
FOR Lab one
what i want
On page 7i need Part A : single melting point determination of unknown sample Table
Page 8 all page, page 9all pages, page 10nothing.
And check every thing i solve
Experiment 1 Melting Point Observations
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Appearance of Unknown 350-1-A-1 -dull white powder
Appearance of Unknown 350-1-B-1 -dull white powder
Part A
packing of tube accomplished using a drop tube.
Amount of compound in melting point (mp) tube = 1 mm
Observations during mp = (see lab manual for a time lapse of step observed)
Temperatures recorded = 68.2-69.1 C
Part B
50:50 mixture created and mixed by mortar and pestle -dull white powder
packing of tube accomplished using a drop tube.
Amount of compound in mp tubes = 1 mm
Observations during mp = (see lab manual for recording of the time lapse of step observed)
Temperatures recorded = 1.B.1 alone = 106.1-106.8 C
mixed mp of 1.B.1 mixed with 4-nitrobenzaldehyde = 106.1-106.8 C
mixed mp of 1.B.1 mixed with 2-methylbenzoic acid = 93.0 – 98.5 C
therefore 1.B.1 id is 4-nitrobenzaldehyde
Experiment 2 Recrystallization Observations
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pages 14, 15, 16, 17
and check the rest of the pages if i solve it right
and check everything i solve
Appearance of Impure Acetanilide? -dull white powder with some dark flecks
Amt weighed = 5.00g
Appearance of solvent selected = distilled water = clear and colorless
Volume of solvent used to dissolve the impure acetanilide = 50 mL
Appearance before charcoal addition = clear/colorless solution with white pptte on bottom of flask
Appearance after charcoal addition = clear/colorless solution with black charcoal powder throughout
and white pptte on bottom of flask
Appearance after gravity filtration = black charcoal powder on filter paper, filtrate = clear and
colorless
Appearance after cool down = crystals formed after 5 minutes, white shiny flakes growing in flask
Appearance of final purified acetanilide – white shiny flakes
Yield of final purified acetanilide = 2.98 g
mp of final purified acetanilide = 113-3-114.0 C
mixed mp of purified acetanilide + mp standard = 113-114 C.
Experiment 3 Distillation Observations
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pages 21,22,23,24
there a missing stuff i didn’t solve
and i want you to check all my work
-uncalibrated thermometer used throughout for all temp. readings
Part A Simple Distillation
Appearance of Impure cyclohexanol? -clear and colorless liquid
Amt weighed/measured = 20.0 mL
Appearance of forerun = clear/colorless solution
Volume of forerun = 6.2 mL
Obs. bp range for forerun = 78 C – 138C (first drop at 78C)
Appearance of product = clear/colorless solution
Yield of final purified cyclohexanol = 13 mL
Obs. bp range of final purified cyclohexanol = 140 C – 155 C
bp of final purified cyclohexanol = 155 C (observed temp at which bp was constant
distillation rate = 1 drop per second, slowing to 1 drop per 3 sec towards the end
Part B Fractional Distillation
Appearance of 50:50 cyclohexene/toluene mixture? -clear and colorless liquid
Amt weighed/measured = 25.0 mL
Appearance of forerun = clear/colorless solution
Volume of forerun = 0.0 mL (no forerun collected)
Obs. bp range for forerun = NA
Appearance of Fraction 1 = clear/colorless solution
Yield of Fraction 1 = 7.3 mL
bp range of Fraction 1= 77 C-83 C
distillation rate = 1 drop per second
Appearance of Fraction 2 = clear/colorless solution
Yield of Fraction 2 = 10.3 mL
Obs. bp range of Fraction 2= 83 C -97 C
distillation rate = 1 drop per second
Appearance of Fraction 3 = clear/colorless solution
Yield of Fraction 3 = 5.5 mL
Obs. bp range of Fraction 3= 97 C -110 C
distillation rate = 1 drop per second
Appearance of Residual in Distilling Flask = clear/colorless solution
Yield of Residual= ~2.0 mL
**the biggest thing to remember to do for this experiment is to do the Barometric Pressure
temperature correction on all your observed boiling point readings. The equation for correcting
the boiling point of a solution is:
corr.bp(C) = obs.bp(C) + ((760 mmHg -obs.BP mmHg)/10 mmHg) x 0.5 C)
where:
corr. = corrected
bp = boiling point
C = degrees Celsius
obs. = observed
BP = barometric pressure, in mm Hg (760 mmHg or torr = sea level pressure)
i.e., “for every 10 mmHg below 760 the BP is, you must correct by adding 0.5 C to the observed
bp.” So for instance, if the observed BP was 700 mmHg, this is 6 x 10 mmHg below 760, and
therefore you must add 6 x 0.5 C, or 3 C to the observed bp.
You need to do the correction for both the lower and upper limit of the bp range (it is the same
number that is added or subtracted from the observed value for both limits).
Please note that you may have any additional number for the actual bp. e.g., for cyclohexanol in
Part A of Exp.3, you may also have observed a particular temperature that was fairly constant
towards the end of the distillation…this is the boiling pt of cyclohexanol and it also needs to be
barom. press. corrected.
