The History of Paint Pigments
Chem 111-404
April 24, 2013
Introduction:
This report expresses five different pigments that were formed during chemical reactions. Three out of the total five reactions went through a metathesis, or double-replacment reaction. A metathesis reaction can be defined as “a chemical reaction in which an element or radical in one compound exchanges places with another element or radical in another compound.” (Webster). The other two pigments underwent a neutralization reaction, which is “A reaction between an acid and a base that yields a salt and water.” (Webster). In both types of reaction two substances are being combined to form a new solution. The metathesis reaction produces a solution and a
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The first half was filtered and stored for the completion of the experiment, while the other half was stored for a week, unfiltered. The next week the unfiltered solution in beaker was filtered and set aside for another week.
The fifth, and final pigment, was Prussian blue. One milliliter of 0.5 M iron (III) chloride was measured into a test tube. Then, 0.25 M solution of potassium ferrocyanide was mixed in. They were then filtered, and left to dry. The next week there were four paint binding options: egg tempura, casein, acrylic, and water color or gum arabic. This experiment used watercolor. The first step was to grind the pigment with water to make a stiff paste. Then, gum Arabic was added in a 1:1 ratio.
Results:
The data produced from the experiment demonstrates that when two solutions are mixed, they undergo a reaction that produces a pigmented or colored precipitate and also a liquid. The precipitate produced then can be fashioned into paint. In the first pigment, chrome yellow was produced. The yellow sodium chromate combined with the clear zinc sulfate created an orange liquid and a yellow precipitate. This is a metathesis reaction that causes the solution to be neutralized. The addition of sodium hydroxide causes the solution to become more basic. After the solution was filtered it created a yellow solid, and when the precipitate was crushed up and gum Arabic was it created a yellow
There was an assortment of different changes indicating that chemical changes were taking place such as change in color or chemicals bubbling when combined with another chemical.
In the Dyes and Crimes laboratory experiment, the phosphorescence, fluorescence, and chemiluminescence properties i.e. traits of several chemicals were examined using (UV) Ultraviolet lamp. Observations on color, intensity, duration of glow, etc. were analyzed to determine the traits of the several chemicals. Correspondingly, the author of the unsigned note was determined through ink extraction, (TLC) Thin Layer Chromatography, (UV-Vis) Ultraviolet-visible spectroscopy along with the Rf values for of each individual sample of ink compared to the unknown: the ink of the author on the unsigned note. Phosphorescence substances
Procedure: In this experiment, various chemicals were mixed together, to determine a reaction. Using two drops from chemical 1 and two drops of chemical two, unless otherwise stated, then recording the type of physical reaction or color changes that occurred.
tube was placed inside, then another test tube with an equal amount of substance would be placed
3. The “new” substances that were formed as a result of chemical change were many. When I took the candle and lit it, it burnt and formed smoke. When I took the wooden split and lit the paper on fire, the color around the green paper changed to be brown, burnt and changed into ashes. Also, I poured Hydrochloric acid and magnesium ribbon in a test tube and it started bubbling and it heated up in the bottom.
During this project, the group will be attempting to turn a penny green. Needed in this experiment will be pennies dated before 1982 because that was when pennies were made of copper. During this experiment, the group will be mixing together different chemical reactions in order to get the penny to turn green. The group is trying to create a patina coating on the penny. Patina is referring to the blue-green layer of corrosion that expands on the surface of copper when it is exposed to oxygen and sulfur compounds. However, instead of using simply sulfur and oxide compounds, like the Statue of Liberty, the experimenters will be using a vinegar substitute. The vinegar is being substituted for the acid rain, the acid is the
When the tip of the rod touched the pH paper, the color of the pH paper became blue.
Drawing the Color Line by Howard Zinn the second chapter from A People’s history of the United States. The authors writes this chapter to explain racism and how it started, “a continent were we can trace the coming of the first whites and the first blacks-might supply at least a few clues” he wants to use history to try to explain why it started. In this chapter Howard Zinn gives us an insight on Slavery and racism in the early 17th century of America. This chapter does not only tell us why slavery accrued but how it happened. The author Howard Zinn tells us how the Americans were simple prone to having slaves because of the circumstances they faced in the early 17th century. It was a period of starvation Howard
Boynton, R.M. 1987. Color. In McGraw-Hill Encyclopedia of Science & Technology (Vol. 4, 165-166) McGraw-Hill, Inc.
The colour of the precipitate was black and were quite small in size, so it was a bit hard to distinguish between the zinc powder present and the copper formed by the displacement reaction because copper formed should be reddish brown is colour – which is also a dark colour and thus two dark colours were hard to be distinguished.
Heavy precipitate emerged immediately and solution turned white in color; solution then became opaque and turned light, bright blue in color.
The colors blue, red, yellow, and green were used in this work
Then we set them under a light for 30 minutes. After the researchers observed the changes in the color of
The art of painting dates back to pre-historic times, the finger used as a paintbrush on the canvas of cave walls. When it comes to painting, artists have many mediums to choose from: acrylics, oils, gouache, fresco, and watercolors. Watercolors is one of the toughest mediums to achieve, its transparent streaks almost impossible to cover up and its various techniques prestigous and precise, but satisfying when accomplished. The incentive a watercolor artist has to get a taste of perfecting their talents is impecable; therefore, striving for perfection can only be accomplished with the understanding of the watercolor history, the use of the tools of the trade, the practice of techniques, and observation of former artists’ approaches.
"A picture can paint a thousand words." I found the one picture in my mind that does paint a thousand words and more. It was a couple of weeks ago when I saw this picture in the writing center; the writing center is part of State College. The beautiful colors caught my eye. I was so enchanted by the painting, I lost the group I was with. When I heard about the observation essay, where we have to write about a person or thing in the city that catches your eye. I knew right away that I wanted to write about the painting. I don’t know why, but I felt that the painting was describing the way I felt at that moment.