Abnormal precipitation: “colored” rain and “chocolate” snow. Reference

Colored rains are often frightening in their appearance: while amazingly colored water is pouring onto the ground, people usually immediately begin to feverishly remember whether there have recently been any chemical releases from an industrial plant located nearby (it becomes especially scary if you find yourself on street when it was pouring black rain). In fact, red, white, yellow, green rain is not always associated with anthropogenic human activity and is often of a natural nature.

Colored rains consist of the most ordinary water droplets, which, before spilling onto the ground, mixed with natural impurities. These could be leaves, flowers, small grains or sand brought into the upper layers of the atmosphere by a strong wind or a tornado, which gave the drops an interesting and unusual shade, for example, chalk particles create white rain.

Black, chocolate, red, green, yellow and white rain can fall everywhere - both on the European continent and elsewhere globe. People have known about strange colored rains for a long time; Plutarch and Homer recalled them in their works. You can also often find their description in Medieval literature.

Rain with a red tint

Precipitation comes in different shades, but red rain makes a particularly shocking impression on people. Showers of this particular color have long been considered an unkind sign and a harbinger of an approaching war. Both ordinary people and eminent philosophers of antiquity have always been wary of such sediments. For example, Plutarch, when he wrote about the red rain that fell on earth's surface after battles with the Germanic tribes, he argued that raindrops acquired their color precisely thanks to the bloody fumes from the battlefield. According to him, it was they who saturated the air and gave the water droplets a brown tone.

Interestingly, it is red rain that falls on the earth’s surface most often (usually either in Europe or near the African continent). Why exactly this happens has long been no mystery to modern scientists, and they do not see any mysticism in this phenomenon.

The cause of red rain is ordinary dust from the African desert (also called trade wind dust), which contains a huge number of red microorganisms:

• A strong wind or tornado lifts dust with red particles into the upper layers of the atmosphere, from where air currents carry it to the European continent.
• Over the European continent, dust mixes with water droplets and colors them.
• After this, the drops fall down in the form of rain, surprising and astonishing the local population.

This is far from the only explanation for this phenomenon. For example, several years ago in India there was red rain for two months (which could not but alarm the local population) - and African dust had nothing to do with it. Because during this period, both the weather and the wind changed their direction several times, while the showers almost never stopped.

The red rain also had a negative impact on the leaves; they quickly became quite dry, but also acquired a dirty gray tint, after which they fell off - a phenomenon that is not typical for India at this time of year.

Scientists have put forward a variety of reasons for this phenomenon. There have been suggestions that the impurities that color the rain red are of extraterrestrial origin and are associated with an exploding meteorite in the upper atmosphere, microparticles of which mixed with precipitation. Another version, which was adhered to by more skeptical scientists, and along with them the Indian government, said that the color of precipitation was quite strongly influenced by spores growing on trees of algae from the lichen family, therefore, the red color of rain is absolutely harmless to living organisms.

Rain is black

Black rain falls much less frequently than red rain. It appears due to the mixing of water droplets with volcanic or cosmic (meteorite explosion) dust. Black rain is often dangerous if it is caused by industrial enterprises whose activities involve, for example, burning coal or refining petroleum products.

For example, in the late 90s, during the war in Yugoslavia, several petrochemical enterprises were destroyed, after which black rain fell, containing a lot of heavy metals harmful to human health and life. organic compounds. Black rain also had a negative impact on environment, since the soil, groundwater and one of the most big rivers Europe - Danube.

Snow White Rain

For regions with chalk rocks, milky rain (white rain) is a fairly common phenomenon, since raindrops here often contain tiny particles of chalk and white clay. At the same time, white rain may well fall in other places on our planet.

For example, in the capital of a European city several years ago there was a milky rain, after which white puddles appeared on the roads, and with big amount foam, which greatly frightened the local residents.

Experts have not been able to fully determine what exactly caused the appearance of such a phenomenon. Some agreed that the white rain fell due to the active construction of houses and roads, which was taking place in the city during this period. Others suggested that the milky rain fell due to the spores of flowering ambrosia, which were flying in the air.

All experts clearly agreed that white rain is dangerous to the health of local residents, especially allergy sufferers, asthmatics, and people with lung and bronchial diseases.

Yellow and green precipitation

You can get caught in green or yellow rain when pollen from various plants (both flowers and trees) mixes with water droplets. For example, when mixed with birch particles, green rain often falls. But in the Omsk and Arkhangelsk regions, water drops contain admixtures of sand and clay, so yellow rain often falls here.

More interesting cases can cause a similar phenomenon. For example, one day yellow rain fell on one of the villages in India, Sangrampur, causing panic among the local population. Fearing the presence of toxic substances in the sediment, tests were carried out, the results of which shocked scientists. It turned out that the green, sometimes yellow rain was ordinary bee excrement (several swarms of bees flew in this area at once), in which traces of honey, flower and mango pollen were found.

Green rain can often fall due to impurities chemical substances. For example, several years ago it rained green in the Krasnoyarsk Territory. After this, people living in this region began to complain of severe headaches and watery eyes.

Despite the fact that colored rains are an interesting, surprising and impressive phenomenon, it is better not to fall under them: you never know what exactly the water drops were mixed with in each specific case. It’s good if nature turned out to be the cause of this phenomenon - then colored rain can even be good for health. But if you are unlucky and you are caught in, for example, white rain or black rain caused by an anthropogenic factor, this will definitely not have the best effect on your health.

Let's imagine this situation:

You are working in a laboratory and have decided to conduct an experiment. To do this, you opened the cabinet with reagents and suddenly saw the following picture on one of the shelves. Two jars of reagents had their labels peeled off and safely remained lying nearby. At the same time, it is no longer possible to determine exactly which jar corresponds to which label, and the external signs of the substances by which they could be distinguished are the same.

In this case, the problem can be solved using the so-called qualitative reactions.

Qualitative reactions are called such reactions that make it possible to distinguish one substance from another, as well as to find out high-quality composition unknown substances.

For example, it is known that cations of some metals, when their salts are added to the burner flame, color it a certain color:

This method can only work if the substances being distinguished change the color of the flame differently, or one of them does not change color at all.

But, let’s say, as luck would have it, the substances being determined do not color the flame, or color it the same color.

In these cases, it will be necessary to distinguish substances using other reagents.

In what case can we distinguish one substance from another using any reagent?

There are two options:

• One substance reacts with the added reagent, but the second does not. In this case, it must be clearly visible that the reaction of one of the starting substances with the added reagent actually took place, that is, some external sign of it is observed - a precipitate formed, a gas was released, a color change occurred, etc.

For example, it is impossible to distinguish water from a solution of sodium hydroxide using hydrochloric acid, despite the fact that alkalis react well with acids:

NaOH + HCl = NaCl + H2O

This is due to the lack of any external signs reactions. A clear, colorless solution of hydrochloric acid when mixed with a colorless hydroxide solution forms the same clear solution:

But on the other hand, you can distinguish water from an aqueous solution of alkali, for example, using a solution of magnesium chloride - in this reaction a white precipitate forms:

2NaOH + MgCl 2 = Mg(OH) 2 ↓+ 2NaCl

2) substances can also be distinguished from each other if they both react with the added reagent, but do so in different ways.

For example, you can distinguish a sodium carbonate solution from a silver nitrate solution using a hydrochloric acid solution.

Hydrochloric acid reacts with sodium carbonate to release a colorless, odorless gas - carbon dioxide (CO 2):

2HCl + Na 2 CO 3 = 2NaCl + H 2 O + CO 2

and with silver nitrate to form a white cheesy precipitate AgCl

HCl + AgNO 3 = HNO 3 + AgCl↓

The tables below present various options for detecting specific ions:

Qualitative reactions to cations

Qualitative reactions to anions

Anion	Impact or reagent	Sign of reaction. Reaction equation
SO 4 2-	Ba 2+	Precipitation of a white precipitate, insoluble in acids: Ba 2+ + SO 4 2- = BaSO 4 ↓
NO 3 −	1) Add H 2 SO 4 (conc.) and Cu, heat 2) Mixture of H 2 SO 4 + FeSO 4	1) Formation of a blue solution containing Cu 2+ ions, release of brown gas (NO 2) 2) The appearance of color of nitroso-iron (II) sulfate 2+. Color ranges from violet to brown (brown ring reaction)
PO 4 3-	Ag+	Precipitation of a light yellow precipitate in a neutral environment: 3Ag + + PO 4 3- = Ag 3 PO 4 ↓
CrO 4 2-	Ba 2+	Formation of a yellow precipitate, insoluble in acetic acid, but soluble in HCl: Ba 2+ + CrO 4 2- = BaCrO 4 ↓
S 2-	Pb 2+	Black precipitate: Pb 2+ + S 2- = PbS↓
CO 3 2-		1) Precipitation of a white precipitate, soluble in acids: Ca 2+ + CO 3 2- = CaCO 3 ↓ 2) The release of colorless gas (“boiling”), causing cloudiness of lime water: CO 3 2- + 2H + = CO 2 + H 2 O
CO2	Lime water Ca(OH) 2	Precipitation of a white precipitate and its dissolution with further passage of CO 2: Ca(OH) 2 + CO 2 = CaCO 3 ↓ + H 2 O CaCO 3 + CO 2 + H 2 O = Ca(HCO 3) 2
SO 3 2-	H+	Emission of SO 2 gas with a characteristic pungent odor (SO 2): 2H + + SO 3 2- = H 2 O + SO 2
F −	Ca2+	White precipitate: Ca 2+ + 2F − = CaF 2 ↓
Cl −	Ag+	Precipitation of a white cheesy precipitate, insoluble in HNO 3, but soluble in NH 3 ·H 2 O (conc.): Ag + + Cl − = AgCl↓ AgCl + 2(NH 3 ·H 2 O) = ) Loading... You might be interested: Proper nutrition Than the work of Pinocchio 80 years of the book by A.N. Tolstoy “The Golden Key, or the Adventures of Pinocchio” Kondratieva Alla Alekseevna, primary school teacher MBOU “Zolotukhinsk secondary school”, Kursk region Description of the material: this material can be used by Salads and snacks Marinated pork in the oven with potatoes Pork marinade offers endless possibilities for improving taste, tenderness and aroma. Juicy meat goes well with fruits, dairy products, herbs and spices, which makes it possible to prepare it in various ways. Salads and snacks Salad with fried chanterelles Salad with pickled chanterelle mushrooms This dish appeared on our holiday tables as an alternative to the usual herring under a fur coat. Chanterelle has gained popularity due to its delicate taste and bright, original appearance, which can decorate any feast. How to prepare salad L Categories Flowers Blanks Beverages Animals Proper nutrition Houseplants Home Economics Latest articles Salad with canned tuna and corn Tuna salad corn pickled cucumber Lenten dumplings – cook at least every day! Lazy cutlets "Tepsi Kebabi" (Turkish cuisine) How to straighten your legs with exercises How to check if an egg is rotten? Is it possible to read character from a man's face? Kefir okroshka diet: weekly menu with recipes Kefir okroshka diet The best varieties of coffee beans, ground, instant: names, list, rating Origin of the expression "bash to bash" Advertising Copyright 2023 Flowers Blanks Beverages Animals Proper nutrition