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Math ability and Culture QotW - Why doesn't an injured spinal cord re-grow? Ask The Naked Scientists. Humans navigate inefficiently in cities. If you treat a copper penny with Ammonia it will turn Blue.
Why does it turn Blue? The ammonia that I am referring to is common household ammonia which is Ammonium hydroxide. Hello justwondering-ga! I was able to find a couple of articles that describe various aspects of the chemical reaction that you are describing.
When ammonia is dissolved in water, the interaction of the ammonia molecules with the water molecules results in the production of ammonium ions and hydroxide ions.
You can actually watch a chemical reaction take place -- mix two things together, each of which has no color, and watch some colored liquid form. In dehydrated copper sulphate there are no copper ions free, the copper is ionically bonded to the sulphate. Why the copper is blue in color? This is the question given to me on which I am having seminar I should explain it for minutes in front of all. Hi Akansha.
I'm afraid your lecture on this topic will be excruciating for you and the listeners if you don't put effort into it. Please read the page, ask a followup question, and engage us in a practice run for your lecture :- Alternately, look up "black body radiation", study it a bit, and I'm betting you'll deliver a fascinating minutes!
Good luck, and Regards,. The oxidation state refers to how many electrons an atom has gained or lost compared to its neutral state. With one or two or three electrons missing the available energy states empty electron shells are different and the electron energy transition jumping to a lower energy state and emitting a photon of a specific wavelength that is the primary contributor to the observable color will be different.
Thanks Ray. It may be beyond Akansha's pay grade, I know it's beyond mine, but this funny business about the color of glowing metals is what forced Max Planck, completely against his will and contrary to his sense of logic, to drag the whole damn world into the wacky age of quantum mechanics :- Regards,.
Why mercury subchloride and mercuric perchloride are white in color and red sulphate of mercury in red color, but these three compounds are derived from mercury?
Hi Suganya. Please try your best to detail what you understood and didn't understand from the previous discussion so we can keep moving forward. A deep blue copper sulphate solution turns pale blue when water is added. Name and describe the phenomenon which causes the change in colour from deep blue to pale blue.
Sorry, Loreal, but I can't get my brain going 'til I've had a proper morning coffee, and I think my wife made the pot with 1 scoop of ground coffee instead of 6. It tastes like dishwater and looks very pale from dilution as well. I'll be back after I make a fresh pot of strong, deep black, coffee :- Regards,. This is because of the Jahn-Teller effect, because the electrons crowd each other. Hi Lorial The amount of light that passes through a solution the colour you see depend upon the concentration of the solution.
The more dilute the solution by adding water the more light in this case blue that passes and the colour is lighter. Heat causes molecules to move faster, whether those molecules are bouncing around in the air or a liquid. Higher temperatures cause more reactions to happen at the surface of the copper. The higher the temperature, the faster chemical reactions can occur. Faster-moving molecules move with more energy, so their collisions with each other are more likely to break connections within a molecule.
More than that, high-energy collisions help to form bonds between two molecules. This is similar to how it is easier to dissolve sugar in hot tea than it is to do so in iced tea. Ever wonder why the sugar always sits at the bottom of your iced tea, even though you have been stirring it for five minutes? Inland and desert areas can be very hot, while coastal regions are cold.
Regions at high elevations are colder than valleys. Often the location where you keep your copper products determines the temperatures that your copper is exposed to. This heat can warm up the entire room or nearby copper objects. The chemical reactions that form patina require the presence of water.
Water exists in the form of moisture in the air, mist, rain, and snow. Some regions have both high temperatures and high humidity, which promotes the chemical reactions that form the patina.
Some regions are very dry, so there is minimal natural water vapor in the air. Copper objects exposed to wet weather are frequently drenched or moist. Some regions have rain for most of the year, while others receive only a few weeks of rain per year. Kettles, water boilers, and pressure cookers release significant amounts of steam that can affect nearby copper objects or ones in the same room.
Copper ore taken from the ground has many impurities in it. Through the process of electrolysis, pure copper is obtained. However, copper can contain impurities in the form of other metals, such as iron, nickel, cobalt and molybdenum. These impurities can also react with oxygen and water vapor, just like copper does, to form compounds that have color.
Iron can form iron oxides that have a reddish brown color. Cobalt can form cobalt oxides that have a greenish-brown color. The amount of impurities in the copper can affect the color of the patina.
In Equation 6 above, copper oxide reacts with sulfur oxide and water to form brochantite, which gives a greenish color to patina. Sulfur exists in the atmosphere in the form of sulfur oxide. One source of sulfur oxide air pollution is through burning fossil fuels, such as oil and gasoline.
In fact, acidic rain that damages buildings and statues gets its acidity in part from the sulfur oxides that mix with water vapor to form sulfuric acid. Other sources of sulfur oxide production in the air are industrial regions that release smoke, such as power plants and chemical production plants. Copper has been a key architectural material throughout history. The Statue of Liberty might be the most famous copper patina in the world. Here are a few more buildings that feature copper patinas in various shades of green:.
The Berlin Cathedral is one of the most recognizable buildings in Berlin. It was built between and , and features five copper domes and multiple copper statues.
Although it was damaged in World War II, it has since been restored, and retains its iconic green patina. Also located in Berlin, the Nordic Embassies are another unique example of copper in architecture, this time with a distinctly modern appearance. It contains buildings representing each of the Nordic Countries, surrounded by a green copper wall that winds its way around the complex. The Belvedere Palace in Vienna is an example of copper as used in Baroque architecture. Built in the early s, the copper roof is still intact years later and looks great today.
Allegedly, the design was inspired by the shape of Ottoman army tents camped outside the city of Vienna. The Temppeliauko Church in Helsinki, Finland, is another stunning piece of modern architecture. Completed in , this church was excavated out of solid granite bedrock, and features a large copper dome surrounded by window panes that act as a skylight.
The church is known for its great acoustics, and has an organ with pipes! The copper adds to the rugged, cave-like interior, while its patina-covered exterior is visible on the top of the hill. The roof is made of a plywood frame covered with a copper plate to protect it from the marine air. Since the building was only opened in , you can see that the roof is still primarily its original brownish copper color, and is slowly developing a green patina.
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