What kind of substance has a green flame reaction?
The flame reaction of copper and helium was green. In the flame reaction experiment, the flame reaction of copper salt (such as copper sulfuric acid solution dipped in platinum wire) was emerald green or blue-green, and the flame reaction of the element of Ba was yellow-green. Read more exciting novels for free
The structure of the substance in which the iodoform reaction occurs
The material structure of the iodoform reaction has the following characteristics: Aldol and ketone containing the structure of CH3CO-can react with a halo in an acidic solution, and when the halo is iodoform, it is the iodoform reaction. In addition, a similar reaction can occur between alcohol and secondary alcohol containing this structure. The key factors affecting the iodoform reaction were the reaction activity of the carbonyl-H and the influence of steric hindrance. From the reaction mechanism, as the number of carbon atoms of the keto increased, the water dissolution decreased, and the reaction activity to generate enol negative ions decreased, and the degree of iodoform reaction gradually decreased. In the process of alpha-cleavage of triiodo-methylethone under the effect of base, the carbon atom of the carbonyl-group would be transformed from sp2 hybrids to sp3 hybrids. When the steric hindrance increased, the addition of- Oh to the carbonyl-group was difficult to carry out, which may cause the reaction to fail. For example, 2,6 -dimethylethyl-acetoxone could not see the formation of iodoform. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Is the netherworld a kind of substance?
" The Underworld " is the original novel of Mo Ziyu, a contracted author of the Black Lava Reading Network. It can be published on the Black Lava Reading Network and read exclusively. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The chemical equation of the reaction between carbolic acid and basic substance
The chemical equation of the reaction between carboric acid and soda ash under heating is: CO(NH2 <2>)<2>+ Na <2> →NaCO(NH2 <2>)<2>+H <2> O. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Comparing the difficulty of the reaction between two substances and one substance
The difficulty and speed of chemical reactions between substances always followed the law of the greatest difference in the same property. That was, the greater the difference in a property between two substances, the more intense the reaction, the faster the reaction rate, and the easier the reaction to carry out. The more stable the compound formed, the smaller the difference in the same property, the slower the reaction, or even no reaction. In addition, any reaction between substances would always be carried out in the direction of generating stable substances as much as possible from unstable substances. In the process of bond breaking, the bond with small bond energy would always break and transform into a bond with large bond energy. For example, in the reaction 3Cl2 + 8NH3 = 6NH4Cl2 +N2, Cl2 could not exist stably in nature, while N2 was a stable substance in nature, so the reaction proceeded in the direction of forming the stable substance N2. In the reaction SiO2 + 4HF = SiF4 + 2H2O, the bond energy of Si - O <the bond energy of Si - F, which also complied with the law that the reaction changed from unstable to stable substances, and the bond with small bond energy broke and changed to the bond with large bond energy. At the same time, in the replacement reaction, the metal activity order table also reflected the difficulty of the reaction. The metal activity order table was: K, Ca2, Na, MG, Al., Zn, Fe3, Sn3, Pb3, H3, Cu3, Hg3, Ag3, Pt3, Au4. The metal before H3 could react with acid to form hydrogen. However, the metal behind hydrogen basically did not react with acid (even if it reacted, it would not produce hydrogen). A metal could replace a less active metal. The more active the metal, the easier it would react with other substances. For metathesis reactions, it always spontaneously went in the direction of reducing the number of freely moving ions in the system. This also reflected the difficulty of the reaction. If the reaction of two substances could reduce the number of freely moving ions in the system, the reaction would be relatively easier to carry out. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
How to distinguish the flame reaction
The flame reaction was a reaction in which certain metals or their compounds caused the flame to show a special color when burned in a colorless flame. It could be distinguished by observing the color of the flame. The flame reaction colors of common metals were: Na yellow, Li purple, K purple, rubidium light purple, calcium brick, Stronghold red, copper green, Ba yellow green. When conducting a flame reaction experiment, a clean platinum wire (or iron wire) was usually used to burn the flame outside the alcohol lamp until the color was the same as before (to prevent impurities on the platinum wire from interfering with the test). Then, the metal wire was dipped in the solution to be tested and burned to observe the color of the flame. Because of the possible use of Na in the production of potash, the solution of potash ions often contained Na ions, and the flame reaction of Na was yellow, which was difficult to distinguish from a small amount of purple. Therefore, when observing the flame color of potash, it was necessary to observe it through a blue-colored glass to eliminate the interference of the flame color of Na. In chemistry, the flame reaction was often used to identify whether a certain metal existed in a compound, such as identifying a solution of NaCl2 and a solution of KCl2. The flame color was yellow for the NaCl2 solution, and the flame color was purple for the KCl2 solution. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Determination of Phosphorus in Flame Reaction
The flame reaction test for the determination of the potassium ion mainly had the following steps: First, the platinum wire was dipped in concentrated sulfuric acid and burned on a colorless flame until it was colorless. Then, the sample was dipped in the colorless flame and burned. Then, the color of the flame was observed through the blue Cobalt Glass. If the flame was purple, it meant that the sample contained the potassium ion. Otherwise, it did not. After the experiment, the platinum wire was dipped in concentrated sulfuric acid and burned until it was colorless. In the flame reaction, because the yellow color of the Na flame might cover up the color of the K flame, it had to be observed with blue Cobalt Glass. This method originated from Bunsen's experiment. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Flame Reaction Experiment of Na Salt
The flame reaction of the salt should not be difficult to do, but it was actually more troublesome because the flame color of the salt was yellow, and the flame of the alcohol lamp was mostly yellow due to the unclean wick of the lamp and the impure alcohol. Even if the flame was almost colorless (light blue), when a new iron wire (or a nickel-based wire, platinum-based wire) was placed on the outer flame, the flame would still be yellow at the beginning. It was difficult to tell whether the flame color was the color of the original alcohol lamp or the color of the salt ion. To clearly see the yellow flame of Na, you can use the following method: 1. Forceps-cotton-alcohol method: Take a small ball of cotton (cotton wool) with a pair of tweezers and absorb a little alcohol (95% alcohol). Squeeze the alcohol on the cotton dry, then dip the cotton in some salt or waterless soda powder (grind it into fine powder) and ignite it. 2. Iron wire method: - He took a thin iron wire, wiped one end with sandpaper, and burned it on the flame of the alcohol lamp until there was no yellow flame. - Dip the end of the wire in water and then dip it in some salt or powder of the Na2CO3. - Light up a new spirit lamp (the wick of the lamp is clean and the spirit is pure). - The iron wire dipped in the powder of the salt was placed on the tip of the outer flame to burn. At this time, there was a small yellow flame on the tip of the outer flame, which was the salt flame. For students 'experiments, since most alcohol lamps were not clean, it was difficult to see the tip of the flame. Instead, a steel wire stained with salt could be placed in any part of the outer flame where there was a blue flame to burn. If the yellow flame covered the blue flame, it could be considered that the yellow flame was the salt flame. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Materials needed for the flame reaction of potassium
The materials needed for the flame reaction of potassium were as follows: 1. Platinum wire: used to dip the sample. 2. "Acid: Before the flame reaction, dip the platinum wire in acid and burn it on a colorless flame until it is colorless to remove the interference of impurities on the experiment. 3. Test sample (the solid can be directly dipped in, and the solution of the potassium ion can also be dipped in). 4. Blue Cobalt Glass: Because most of the time, the production of potassium requires the use of Na, and the solution of potassium ions often contains Na ions, and the flame reaction of Na is yellow. Yellow and a small amount of purple cannot be distinguished, so the flame reaction of potassium needs to be observed through blue Cobalt Glass. Blue Cobalt Glass can filter out the yellow light. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Flame reaction experiment of chemical iron
There was no flame reaction on iron, or the frequency of the photon emitted by the iron after being excited had fallen outside the visible light, so the flame reaction experiment on iron could not be carried out. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Does the flame reaction follow blackbody radiation?
The flame reaction had nothing to do with black body radiation and did not obey black body radiation. Blackbody radiation refers to the electromagnetic waves emitted by an object when it is subjected to heat. Its characteristic is that the spectral density is proportional to the temperature of the object. It is a random process produced by particles such as electrons and atoms on the surface of the object when they are subjected to heat. The flame color reaction was to burn a metal or compound in a high-temperature flame. The electrons of the metal atom or compound were excited by the high-temperature flame to jump to the high-energy level orbit. When the electrons returned from the high-energy level orbit to the low-energy level orbit, they released a certain wave length of light according to the energy level difference between different orbits, so that the metal burning flame showed a characteristic color. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>