Question

need a little help with my lab i am kind of confused

9:50 am 12:40 pm Lab Time (circle): 8:00 am 2:30 pm Pre-Lab chemical structures of methanol, ethanol, and 1-pre IHH HHH t-C-OH H-e-(-014 H-ec.coH It HH methuri Ethan 1. propane! Data Absorbance for 1 Alcohol Concentration Absorbance for Methanol Absorbance for Ethanol propanol 0.323 0.065 10.125 0.081 10.230 0.209 20% T 0.129 0.626 0.152 30% 0.496 71.781 0.127 40% 11.069 0.199 1 0.323 Water = 0.011

Answer 1

Answer 1 and 2 are already correct.

Answer 3

Propanol is most damaging. It is indicated by highest absorbance at all concentrations.

More absorbance means more color, which means more release of pigment. Release of pigment occurs with damage to membranes.

More is the damage, more will be pigment and hence more will be absorbance.

Answer 4

Larger is the size of alcohol, more is the damage. It is indicated by the order of absorbance at a given concentration which is maximum for propanol and minimum for methanol.

This is because, large size means more hydrophobic part. This results in better solubility of lipids of biological membranes. Hence, larger alcohol causes more dissolution of biological membranes.

Answer 5

Isopropanol is a branched chain alcohol. Its structure is

CH3 ОН Нас CH нсон 2-propanol 1-propanol

The hydrophobic character of isopropanol is less than 1-propanol because branching decreases surfacea area which then increases water solubility.

Hence, interaction with lipid is less resulting in less damage to membranes and lower absorbance values.