User:Elizabeth Ghias/Notebook/Experimental Chemistry/2013/02/11: Difference between revisions
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|style="background-color: #EEE"|[[Image:BDLlogo_notext_lr.png|128px]]<span style="font-size:22px;"> Experimental Chemistry</span> | |style="background-color: #EEE"|[[Image:BDLlogo_notext_lr.png|128px]]<span style="font-size:22px;"> Experimental Chemistry</span> | ||
|style="background-color: #F2F2F2" align="center"| | |style="background-color: #F2F2F2" align="center"|[[File:Report.png|frameless|link={{#sub:{{FULLPAGENAME}}|0|-11}}]][[{{#sub:{{FULLPAGENAME}}|0|-11}}|Main project page]]<br />{{#if:{{#lnpreventry:{{FULLPAGENAME}}}}|[[File:Resultset_previous.png|frameless|link={{#lnpreventry:{{FULLPAGENAME}}}}]][[{{#lnpreventry:{{FULLPAGENAME}}}}{{!}}Previous entry]] }}{{#if:{{#lnnextentry:{{FULLPAGENAME}}}}|[[{{#lnnextentry:{{FULLPAGENAME}}}}{{!}}Next entry]][[File:Resultset_next.png|frameless|link={{#lnnextentry:{{FULLPAGENAME}}}}]]}} | ||
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==Objective== | ==Objective== | ||
To crosslink the films prepared last class, to test the effects of using a lower molecular weight PVOH on the film, and to prepare a 0.2 M NaOH solution for use next class. | |||
==Description== | ==Description== | ||
<u>Crosslinking</u> | |||
# Determined the concentration of HCl needed, by determining the amount of H+ in the H<sub>2</sub>SO<sub>4</sub> used in previous crosslinking. | |||
#* 20ml of 100% H2So4 in 1 L of H20 was used, assuming complete dissociation | |||
#** 20ml* 1.84g/ml ÷ 98.079g/mol = 0.375moles of H2SO4 ÷ 1 Liter= 0.369 Molar H2SO4 | |||
#** 0.369mols of H2SO4/L * 2mols HCl/1mol of H2SO4 = 0.7M HCl → 6ml of 12 M HCl | |||
# Heat up a solution of 94 mL water and 6 mL 12 M HCl to 70°C | |||
# Place the film in the solution and heat for 1 hour. | |||
# Prepare a solution of bicarbonate (1.68 g in 100 mL). | |||
# At the end of one hour, remove the films from the HCl, rinse with water, then place in the sodium bicarbonate solution for 15 minutes. | |||
# Then remove the films from the bicarbonate solution and place in water. | |||
# Leave the films in water until Friday. | |||
<u>Preparation of Lower Weight PVOH Films</u> | |||
# Measured out 6 1 g samples of PVOH (MW = 22,000) | |||
# Prepared a solution of 0.22 g phenol in 10 mL water. | |||
# Dissolved the PVOH samples in 30 mL water (in 100 mL beakers) | |||
# Once the PVOH had dissolved, the corresponding amounts of phenol solution were added (1% film = 1 mL, 0.1% = 0.1 mL, 0.01% = 0.01 mL, 8.5% = 8.5 mL) | |||
# 1 mL glutaraldehyde was added to each film | |||
# The solution was allowed to stir and then was poured into an plastic dish and allowed to evaporate until Friday. | |||
<u>NaOH Calculations and Preparation</u> | |||
* need to prepare 50 mL of a 0.2 NaOH solution from a 0.5 N NaOH soln. | |||
(0.5 moles/L)(X) = (0.2 moles/L)(0.05 L) → X = 0.02 L = 20 mL | |||
# Measure out 20 mL 0.50 NaOH | |||
# Add to 30 mL water | |||
# Save for use on Friday. | |||
==Data== | ==Data== | ||
No data was collected today. | |||
==Notes== | ==Notes== | ||
<u> Description of Films Prepared Last Class</u> | |||
* 1% film prepared in Erlenmeyer flask looked the best, was uniform, etc. | |||
* 0.1% and 9% films were not uniform, had lumps of PVOH | |||
* The poor quality of the films was attributed to the high molecular weight of the PVOH. | |||
Latest revision as of 22:26, 26 September 2017
Experimental Chemistry | Main project page Previous entry Next entry |
ObjectiveTo crosslink the films prepared last class, to test the effects of using a lower molecular weight PVOH on the film, and to prepare a 0.2 M NaOH solution for use next class. DescriptionCrosslinking
(0.5 moles/L)(X) = (0.2 moles/L)(0.05 L) → X = 0.02 L = 20 mL
DataNo data was collected today. NotesDescription of Films Prepared Last Class
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