CHEM 208 Study Guide - Soap Film, Hard Water, Zinc Oxide

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coralalpaca939

15 Jul 2014

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Document Summary

Soaps are manufactured from combinations of natural and renewable resources. Soaps are biodegradable and thus do not pollute bodies of water. Formation of soap film (or scum) in water containing ca2+ and mg2+ ions (hard water). The calcium and magnesium ions react with soap molecules to produce calcium and magnesium salts of fatty acids. These salts are insoluble in water and impair the surfactant properties of soap because the amount of soap available for cleaning is reduced. Soap scum is difficult to rinse away and can be visible, i. e. , on fabrics, bathtubs and sinks. Poor adaptability to diversity of fibers, washing temperatures and water conditions. Tendency to clog sewage systems due to their gelling properties. Detergents are less affected by calcium and magnesium ions in water, thus acting as better cleaning agents and almost eliminating the film formation. Detergents perform well under diverse conditions such as adaptability to diversity of fibers, washing temperatures and water conditions.

Related Questions

help with whole page please

I am doing an experiment on saponification. we conducted a hard water test at the end with 4 different test tubes. this experiment went as follows

"Hard Water Reactions.

Place about one-third spatula full of the soap you have prepared in a 50-mL beaker containing 25 mL of water.

Warm the beaker with its contents to dissolve the soap.

Pour 5 mL of the soap solution into each of 5 test tubes (nos. 1, 2, 3, 4, and 5).

Test no. 1 with 2 drops of a 5% solution of calcium chloride (5% CaCl2), no. 2

with 2 drops of a 5% solution of magnesium chloride (5% MgCl2), no. 3 with 2 drops of a 5% solution of iron(III) chloride (5% FeCl3), and no. 4 with tap water. The no. 5 tube will be used for a basicity test, which will be performed later.

Record your observations on the Report Sheet. "

OUR RESULTS ARE AS FOLLOWS

test tube #4 (water) : Solution turned an thick orange color, no transparency

Test tube #3 (iron III chloride): Solution turned an thick orange color, no transparency

test tube #2 (magnesium chloride): Solution turned an extremely cloudy color, no transparency

test tube #1 (calcium chloride): Solution turned a cloudy white color, solid particle was formed in the middle along with a few bubbles on the top

my question is, what do the results for each test tube mean? i am having trouble writing up my discussion. the full lab link is as follows: http://www.seattlecentral.edu/faculty/ptran/bastyr/Summer%2006/organic/Organic%20Exp/Experiment4Preparation%20and%20properties%20of%20a%20soap1.pdf

This is all the info we are given to make our own procedure.