To calculate the pressure of hexanol while we made a vacuum, compare them with the results obtained by our classmates which are working with methanol, ethanol, propanol, butanol, pentanol, heptanol and octanol, and learn how to create a plastic model of a molecule of hexanol.
Materials:
- Hexanol
- Shlenk tube
- Stand
- 2 Rubber bands
- Clamp
- Interphase
- Gas sensor
- Rubber tube
- Computer with Logger Pro.
Background by Elisa Millán:
According to the Encyclopedia Britannica vapor pressure is the pressure exerted by a vapour when the vapor is in equilibrium with the liquid or solid form, or both, of the same substance—i.e., when conditions are such that the substance can exist in both or in all three phases. Vapour pressure is a measure of the tendency of a material to change into the gaseous or vapour state, and it increases with temperature.
Oral Procedure by Claudia Falcón:
Results:
Table 1: Vapor pressure depending on the number of carbons
Graph 1:
Explanation of best fitting line:
The relation between the variables is that the lower the number of carbons, the higher the vapour pressure. Meaning, in the graph the best fiitting line has an exponential appearance due to the inversily proportional relationship between the independent and dependent variable.
However, in order to desing a straight fitting line, we just need to calculate the inverse of each pressure value and use them as the independent variable. If we apply it, the regression coefficient might be altered.
Conclusion of the Experiment by Carmen Lérida:
Observations of the graph by Marina Bayón:
Scientific reasoning:
The scientific reason of the results obtained in the lab is that when an alcohol contains a huge amount of carbon atoms the chain of carbons will be more fragile, meaning less temperature is needed in order to brake the carbon atom chain. Therefore, when we need less temperature that alcohol will excert less vapor pressure.
For instance, propanol exerts less amount of vapor pressure as the chain of carbons is only composed of three of them, while ethanol change is created by six carbon atoms so the chain is more fragile, consequently it will need less tempeture and it will exert less amount of vapor pressure.
Bibliography:
- En.wikipedia.org (2013). Hexanol - Wikipedia, the free encyclopedia. [online] Retrieved from: http://en.wikipedia.org/wiki/
Hexanol[Accessed: 23 Mar 2013]. - En.wikipedia.org (2005). 1-Hexanol - Wikipedia, the free encyclopedia. [online] Retrieved from: http://en.wikipedia.org/wiki/
1-Hexanol [Accessed: 23 Mar 2013]. - En.wikipedia.org (1892). Chemical nomenclature - Wikipedia, the free encyclopedia. [online] Retrieved from:http://en.wikipedia.org/wiki/
International_Union_of_Pure_ and_Applied_Chemistry_ nomenclature [Accessed: 23 Mar 2013]. - Encyclopedia Britannica (n.d.). vapour pressure (physics). [online] Retrieved from: http://global.britannica.com/EBchecked/topic/623199/vapour-pressure [Accessed: 7 Jun 2013].
- Ivy-rose.co.uk (2012). Naming Alcohols : Names of Alcohol Compounds : Organic Chemistry. [online] Retrieved from: http://www.ivy-rose.co.uk/Chemistry/Organic/Naming-Alcohols.php [Accessed: 23 Mar 2013].
- Pubchem.ncbi.nlm.nih.gov (n.d.). 1-hexanol - PubChem. [online] Retrieved from: http://pubchem.ncbi.nlm.nih.
gov/summary/summary.cgi?cid= 8103 [Accessed: 23 Mar 2013]. - Rsc.org (2013). 1-Hexanol- Learn Chemistry. [online] Retrieved from: http://www.rsc.org/learn-
chemistry/resource/ rws00007812/1-hexanol [Accessed: 23 Mar 2013]. - Sigmaaldrich.com (2012). 1-Hexanol, reagent grade, 98% | CH3(CH2)5OH | Sigma-Aldrich. [online] Retrieved from:http://www.sigmaaldrich.com/
catalog/product/sial/h13303lang=es®ion=ES [Accessed: 23 Mar 2013].
