We bring to your attention a set of final Olympiads for preschoolers who will become first-graders in the near future. All tasks are designed to assess the child’s knowledge base and readiness for school. Completing the tasks of developmental olympiads will allow the child to broaden his horizons, increase his interest in learning, and develop perseverance and determination.

We invite you to take part in the Developmental Olympiad in Mathematics. The tasks of the Olympiad meet the requirements for preparing a preschooler for school in the direction of “The Human World: Professions, Transport, Dishes, Furniture, Cooking, etc.”

Diplomas of participation in the Olympiad are available for downloading immediately after receiving your application.

Procedure for holding the Olympiad:

Assignments for the Olympiad “I KNOW THE WORLD” can be found here.

Rules of participation:

1. Necessary (a teacher or parent of the participant can register).
2. Read the Regulations on the Olympiad.
3. Download the form with the task for the Olympiad. (Tasks will be available for downloading only during the Olympiad)
4. Print a receipt and pay the registration fee for participation in any way convenient for you . The registration fee for participation is 90 rubles for each participant. Organizational fees for a group of participants are paid by the Curator with one receipt for the total amount.
5. IMPORTANT! A copy of the receipt must be attached to your application, REGARDLESS OF THE PAYMENT METHOD. If you pay for participation using electronic money (Qiwi, Yandex-Money, etc.), A RECEIPT IS MANDATORY. In the section of our website you can find out where and how you can find a copy of the receipt when paying with electronic money.
6. Follow the link provided in the Regulations of the event you have chosen to download the answers to the Olympiad.
7. Carefully fill out all fields of the competition application. Be careful when filling out the form to upload your entry. The data you enter will be used when processing documents.

For preschoolers, parents or teacher-curators provide assistance in completing assignments, filling out the form, and submitting the form with answers.

After successful submission, you should receive a notification about the process of reviewing the work by the moderator to the email address specified in the application. Works are reviewed by moderators within three working days.

After approval, you should receive a notification about the publication of your work. If this notification is not received within more than three days, you need to re-upload the work.

Competition entries are not published on the website and will not be available for public viewing.

Acceptance of works for participation is carried out only by independently filling out an electronic application on our website www.site. Materials sent to our email will not be accepted.

Requirements for work registration:

The size of the answer file should not exceed 10 MB. Answer forms can be filled out manually or in WORD text format. When filling out the answer form manually, a photo or scan of the form is uploaded to the application form.

Applications for participation are completed for each participant separately for each Olympiad.

Encouragement of winners:

Participants who scored:

100-90 points, are the Winners of the Olympiad and take 1st place;

90-80 points, are Olympiad Prize-winners and take 2nd place;

80-70 points, are Olympiad Prize-winners and take 3rd place;

70-60 points are Olympiad laureates;

the rest are Members.

The jury determines the Winners of the Olympiad, who took 1st, 2nd, and 3rd places, Laureates and Participants of the Olympiad.

The winners are awarded Diplomas of the Winner of the All-Russian Final Olympiad.

The laureates are awarded Diplomas of the Laureate of the All-Russian Final Olympiad.

Participants are awarded Certificates of Participation in the All-Russian Final Olympiad.

Teachers who trained the Winner or Laureate are awarded Teacher Diplomas. If your participant does not take a prize, you will receive a Certificate of the teacher who prepared the participant in the All-Russian final Olympiad.

Procedure for issuing thank you letters:

1. For teachers who prepared 10 or more participants, letters of gratitude are issued*. An application for receiving a letter of gratitude must be sent to the email address . The application must indicate the full names of the participants who took part in the Olympiads; Full name of the curator for whom a letter of gratitude must be issued, position (if necessary), name of the educational institution (if the name differs from that indicated in the applications for participation). Letters of gratitude are issued within 3 working days from the date of receipt of the application. Thank you letters will be sent electronically.

2. For educational institutions whose students took part in Olympiads (more than 15 participants), letters of gratitude are issued*. An application for receiving a letter of gratitude must be sent to the email address . The application must indicate the full names of the participants who took part in the Olympiads; name of the educational institution for which it is necessary to issue a letter of gratitude; if necessary, indicate the full name of the head of the educational institution. Letters of gratitude are issued within 3 working days from the date of receipt of the application. Thank you letters will be sent electronically.

Correspondence Olympiad in Biology and Ecology

On the basis of the Republican Ecological and Biological Center (REBC) of the Kabardino-Balkarian Republic in Nalchik, correspondence Olympiads for schoolchildren in biology and ecology are held annually. Anyone can take part in them – students in grades 6–10. All schools in the republic have the opportunity to receive assignments for the correspondence Olympiad in printed or electronic form. Over the past ten years, we have gained experience in selecting assignments, sending them to all schools in the republic, summing up the results of olympiads and awarding the winners.

Recently, we have moved from open test tasks to closed ones, requiring short and clear answers. In the process of formulating such answers, students develop the ability to highlight the main thing and briefly express their thoughts.

Students are asked to complete 10 tasks. The answers must be written down on the assignment sheet, in which the appropriate space is provided for this (see Appendix). Answers are scored based on the difficulty of the task.

In this publication, we offer questions and assignments for grades 6–8 of the Republican Correspondence Olympiad “I Explore the World,” held in September–October 2004*

I'm exploring the world

Assignments for 6th grade

Task No. 1. What is an iceberg? Where and how do icebergs form? What is their significance for humans?

Task No. 2. What do the words "aphelion" and "perihelion" mean? What unites these concepts?

Task No. 3. If you take a cup of boiling water, a cup of sand of the same temperature and a bucket of hot water out into the cold, which will cool down faster? What factors have the greatest influence on cooling?

Task No. 4. Place three jars of cold, warm and hot water on the table. Dip one finger at a time into hot and cold water, hold, and then simultaneously dip both fingers into a jar of warm water. How will you feel? Explain why this happens?

Task No. 5. What was the first thermometer? Who invented it? On what factors did his testimony depend and on what physical phenomenon was his action based? Why was it inaccurate?

Task No. 6. It is known that bodies expand when heated and contract when cooled, i.e. their density increases. However, when water freezes, the resulting ice does not sink, but floats and breaks the container in which it is located. Why?

Task No. 7. If you leave water in a small container, it will disappear after a while. When we get out of the water, we feel chills. What phenomenon are these two facts associated with? What factors have the greatest influence on it? Is this phenomenon typical only for liquid substances or for solids too?

Task No. 8. Is it possible to pour a teaspoon of salt into a glass filled to the brim with water without the water starting to overflow? Why?

Task No. 9. The earth is inhabited by organisms of various sizes. How long do they live and is their size related to life expectancy?

Task No. 10. There are two expressions: “aquatic plants” and “algae”. Are there any differences between them? Give examples.

Sample answers

1. Icebergs are huge blocks of continental ice that break off from coastal glaciers in Antarctica and Greenland and float in the ocean. Icebergs can pose a danger to ships. It is possible to use them as a source of fresh water.

2. Planet Earth moves around the Sun. The point of its orbit farthest from the Sun is aphelion; the closest to the Sun is perhelion.

3. The sand will cool first to 0 °C, and then lower, then the water in the cup will freeze, and later ice will appear in the bucket. The cooling rate is affected by the heat capacity - for sand it is less than that of water, and the size (mass) - in a bucket of water it is much larger than in a cup.

4. The finger that was kept in hot water will be cool, and the one that was kept in cold water will be warm, since the concepts of “warm” and “cold” are relative. Human sensations are also relative: the same air temperature can be perceived differently, depending on the circumstances.

5. The first thermometer was invented by Galileo - it was an inverted flask in a vessel with water. The thermometer readings were based on the expansion of air when heated - the warmer it was, the less water there was in the flask, but also depended on changes in atmospheric pressure. Therefore, such a thermometer was inaccurate.

6. Water has special properties: its highest density is observed at a temperature of 4 ° C, and with a further decrease in temperature, the density decreases again. When cooled to 0 °C, ice is formed, which is lighter than water and therefore does not sink. The volume of ice is greater than the volume of water, so it can rupture the container it is in if it is not strong enough.

7. The phenomenon of evaporation. When a liquid evaporates, energy is consumed, so both the liquid itself and the object with which it comes into contact are cooled during evaporation. The rate of evaporation depends on temperature and open surface area - water from a saucer will evaporate faster than from a bottle. Some solid substances can also evaporate: naphthalene, iodine, camphor, ice, “dry ice” (carbon dioxide frozen to a solid state).

8. Yes, if you add salt in small portions so that it has time to dissolve. There are empty “gaps” between the water particles (molecules), and the salt particles (molecules) fit between the water particles.

9. It is impossible to calculate life expectancy based on size, but in general, the larger the organisms, the longer they usually live. Bacteria can live for several minutes, insects for several months, weeks or days, rodents and small birds for several years, elephants and whales live for 50–70 years. Small organisms begin to reproduce early, leave many offspring and die, while large animals take a long time to mature and have a few offspring, which they care for for a long time.

10. Algae belong to the lower plants, they are weakly divided (they do not have true leaves, roots, stems), they do not have flowers and fruits. There are unicellular and multicellular algae (chlorella), filamentous - ulotrix, brown - kelp, green - hara, etc. But higher (flowering) plants can also grow under water - for example, elodea, pondweed, and bladderwort.

Assignments for 7th grade

Task No. 1. Our “northern” orchids are no less interesting than their tropical counterparts. Why are our orchids such as lyubka, nesting, and insect-bearing orchids interesting? Orchids of which ecological group grow only in tropical forests and are absent in ours?

Task No. 2. What is “weeping grass”, what is its scientific name? “What are she and some other plants crying about? What is the “crying” of plants, how and why does it happen?

Task No. 3. What is a flower clock? Who and where arranged them for the first time? Are such clocks always accurate?

Task No. 4. Typically, the roots of a plant are immersed in the soil and supply it with water and substances dissolved in it. But there are completely unusual roots - what do you know about them? What is their purpose?

Task No. 5. How do soil and plants influence each other? Can plants grow without soil?

Task No. 6. What type of forest do you know? Where do they grow?

Task No. 7. How did the following plants get their names: hold-the-tree, bashful mimosa, bottle tree, candy tree, berry yew?

Task No. 8. What are the main methods of nutrition characteristic of animals and what is their main difference from the nutrition of plants?

Task No. 9. What “clothes” did Egyptian mummies wear? What features of this clothing allowed the mummies to survive to this day?

Task No. 10. Aspirin is probably the most widely known medicine. Do you know when it was discovered and what plant gave it its name?

Sample answers

2. Weeping grass – loosestrife. Plant “crying” – guttation – is the appearance of water droplets on the leaves. “Crying” occurs in conditions of excess moisture, which in humid air does not have time to evaporate in the usual way and is removed in the form of drops through special holes - hydathodes. The mantle, arrowhead, and aroids are distinguished by their abundant “crying.” These plants are called living barometers, or weather forecasting plants - their “crying” indicates an increase in air humidity, which often occurs before rain.

3. The flower clock was developed by Carl Linnaeus, who grouped plants with different opening and closing times in his flowerbed in Uppsala (Sweden). The flower clock “works” correctly only in dry sunny weather.

5. The chemical and mechanical composition of the soil and its moisture determine the species composition of the plants growing on them. In turn, vegetation can change the characteristics of the soil: sphagnum causes waterlogging; eucalyptus drains the places where it grows; Legumes enrich the soil with nitrogen. Humus is formed from plant residues - an important component of the soil, ensuring its fertility.
Plants can grow without soil if the whole plant or its roots are immersed in water in which the necessary mineral salts are dissolved. There are many floating aquatic plants in nature; artificial cultivation of ordinary plants without soil - hydroponics.

6. Coniferous northern forest - taiga; temperate forest of coniferous and deciduous species - mixed; Broad-leaved forests grow to the south. Tropical rain forests grow near the equator. In the tropics, on the ocean shore, mangrove forests grow in areas flooded with water. ( When answering, students can give and other examples of forest communities.)

7. Numerous thorns on the thick elastic branches of the tree cling to clothes, skin, and do not allow passage; the leaves of mimosa pudica fold and fall when touched; the trunk of the bottle tree is very thick and serves to store water for the dry period; the growing stalks of the candy tree taste sweet; in yew, a bright juicy shell is formed around the seed, reminiscent of a berry (although it is not a berry - conifers, or gymnosperms, do not produce real fruits.)

9. The Egyptians wrapped the bodies of the dead in strips of fabric impregnated with resins that did not allow air to pass through and had bactericidal properties.

10. Aspirin is acetylsalicylic acid. The name of this substance comes from the name of the willow - Salix, in the bark of which it is contained. As far back as 2,400 years ago, the ancient Greeks used willow bark extract for medicinal purposes. However, salicylic acid was isolated in 1839 from spirea. In 1853, a more complex substance was obtained - acetylsalicylic acid. In 1899, this drug was given the name aspirin.

Assignments for 8th grade

Task No. 1. Photo mystery. Many people are not even aware of the existence of these living fossils, which lived on Earth 200 million years ago and have remained virtually unchanged since then. Meanwhile, they can be found in the most ordinary puddle. Who are they? What do you know about them?

Task No. 2. Many animals travel for various reasons. What are these reasons and what are such trips called?

Task No. 3. Some plants live entirely or partially at the expense of other plants. What are these plants called? What features distinguish them? Give examples.

Task No. 4. Sometimes predatory animals attack people. What are the reasons for the appearance of “man-eating” predators?

Task No. 5. As practice shows, people bitten by snakes more often die not from the effects of the poison, but from the consequences of the “help” that was incorrectly provided to them. Do you know what you should and should not do if you are bitten by a snake?

Task No. 6. Who is called the “black widow”? Why is it scary and how did it get its name? Where can she be found?

Task No. 7. Why 150 years ago the Russian government exiled convicts not only to Siberia, but also to the Caucasus? What danger threatened people’s lives, more than war, and how was it eliminated?

Task No. 8. What did the red flag mean in the Middle Ages, raised on the mast of a ship or over the walls of a city? Why did he inspire mortal terror in people? What animals are associated with this horror and why?

Task No. 9. Crabs usually live in sea or fresh water, but land species are also known in warm countries. What adaptations allow them to live on land?

Task No. 10. Marine worms (worm-like organisms - pogonophores) are known to live on the walls of underwater volcanoes at water temperatures of about 100 °C. However, unique endurance records belong to other worms. What do you know about this?

Sample answers

1. These are shieldfish - representatives of the class of crustaceans, reaching a size of several centimeters. They live in puddles and stagnant bodies of water. They lay eggs (each female - up to several thousand), which, after the reservoirs dry out, thanks to special shells, can remain viable for many years. If the reservoir is filled with water again, larvae emerge from the eggs after 2–3 days, which feed on small invertebrates and detritus and after 2 weeks become adults and begin to lay eggs.

2. Directed movements of animals are called migrations. One of the main reasons is different conditions throughout the year - changes in temperature and the ability to obtain food. For birds, these are autumn and spring migrations or feeding migrations over shorter distances (migration - thrushes, crossbills). Migrations to places where deer and whales are currently making more food. Animals also migrate from places where they constantly live and feed to breeding grounds (fish: salmon, eels; sea turtles).

4. People can be attacked by lions, tigers, leopards, wolves, etc. But only individual individuals become cannibals, usually sick, weakened or wounded, unable to hunt traditional prey. In hungry years, predators can also attack domestic animals.

5. Immediately after the bite you should try to suck out the poison from the wound; after five minutes it is too late to do this. It is necessary to lay the person down and provide him with peace. Give plenty of fluids. See a doctor as soon as possible. Do not cauterize the bite site, apply a tourniquet, or give alcohol.

6. “Black widow” is the name given to karakurt, a black poisonous spider whose bite can be fatal to humans and animals. Karakurts are found in deserts and semi-deserts of Asia and America. The female karakurt is larger than the male and after mating often eats him, which is why this spider got its name.

7. Nowadays the Caucasian coast is a resort, but 150 years ago these were disastrous places where malaria was rampant, claiming thousands of lives. As a result of the drainage of the swamps and the acclimatization of the Gambusia fish, which eats the larvae of mosquitoes that carry the malaria pathogen, foci of this disease were suppressed.

8. A red flag meant there was a plague on the ship or in the city. The population of entire cities died from the plague. The carriers of plague are rodents: rats, gophers, gerbils, and fleas living on them.

9. Land crabs have a dense shell that protects them from drying out, their respiratory organs are located in the legs of the membrane, penetrated by a network of capillaries, their eggs develop in a special chamber that protects them from drying out. But in places where it is very dry and there is no source of water nearby, crabs cannot live.

10. The record holders for survival among worms are rotifers - being in an inactive state, they are able to survive in a vacuum, tolerate the temperature of liquid nitrogen (-273 ° C), and boiling.

To be continued

Application.

Sample assignment for 8th grade

* When preparing the material for publication, the wording of some assignments was changed in accordance with the editorial rules.

Full name of the participant
City (village), district
Educational establishment
FULL NAME. teachers

Cipher
Job No.											Sum

1. Adaptation to the environment:

a) is inherent in living organisms from the moment of their birth;

b) occurs through long-term training of the body;

c) is the result of long-term natural selection;

d) is the result of artificial selection;

2. Organisms capable of living in various environmental conditions are called:

a) stenobionts;

b) oligobionts;

c) commensals;

d) eurybionts;

3. If the population size (density) increases excessively:

a) animals reproduce faster and more efficiently;

b) living conditions for all individuals are improved, and their protection from predators increases;

c) individuals stop reproducing, their life expectancy is reduced, aggressiveness increases, and stress arises;

d) competition between males for a female decreases;

4. The following phenomenon is not associated with periodic changes in the environment:

a) photosynthetic activity of plants;

b) hibernation of animals;

c) autumn leaf fall;

5. Coprophagia occurs:

a) in hares;

b) in hippopotamuses;

c) in elephants;

d) in tigers;

a) accelerating the growth of the victim’s body;

c) increased nutrition of the victim;

d) reduction of the victim’s diet;

7. Limiting environmental factors determine:

a) location of the species in the ecosystem;

b) species range;

c) ecological niche of the species;

d) mutation frequency;

8. Soil as a habitat includes all groups of animals, but the bulk of its biomass is formed by:

a) large predators (1st order consumers)

b) saprophages (saprotrophs);

c) producers (autotrophs);

d) heterotrophs - consumers of the 2nd order

9. The identification of life forms depending on the types of habitat and methods of movement is typical for the following groups of animals:

b) animals;

d) arthropods.

10. Water has become a secondary habitat:

a) for a number of fish;

b) for some amphibians;

c) for some mammals;

d) for echinoderms.

11. The ecosystem is:

a) a site of biogeocenosis;

b) an intermediate link between the biocenosis and the biosphere;

c) functional part of the biota;

d) a structural unit of the biosphere.

1 2. The ecosystems most sensitive to the impact of anthropogenic factors are located:

a) on land in the temperate zone;

13. Ecosystems can rightfully be considered accumulators of various wastewater, “natural orderlies” and “purification plants of nature”:

Ecology

Full name of the participant
City (village), district
Educational establishment
FULL NAME. teachers

Cipher
Job No.											Sum

Choose one correct answer from the four given.

1. The following are not heterotrophs:

b) decomposers – saprotrophs and iron bacteria;

c) consumers of the 2nd order;

d) producers

2. The ratio of productivity and biomass shows:

a) the rate of consumption of food resources;

b) the rate of growth of organic matter;

c) the rate of biomass consumption per unit time;

d) metabolic rate

3. Some of the most unstable ecosystems include:

a) rock ecosystems;

b) meadows and steppes;

c) taiga forests;

d) deciduous forests

4. The edificatory species (they determine the structure and composition of phytocenoses) in the southern steppes are:

a) meadow timothy and awnless brome;

b) feather grass and fescue;

c) meadow foxtail and wormwood;

d) hedgehog grass and meadow fescue.

5. The ecosystems most sensitive to the impact of anthropogenic factors are located:

a) on land in the temperate zone;

b) on land in the tropics and subtropics;

c) on land in northern latitudes;

d) in marine areas

6. The ecosystem (or community) that emerges at the site of the fire is called:

a) ruderal ecosystem (community);

b) segetal community (formed by weeds);

c) pyrogenic ecosystem (community);

d) pioneer (initial) ecosystem (community)

7. Car exhaust is a source of lead, which has a detrimental effect on:

a) central nervous system, autonomic nervous system;

b) kidneys and the entire excretory system;

c) primarily the respiratory system;

d) cardiovascular system

8. Constant consumption of mineralized water leads to changes in the functioning of various organ systems, in particular, it causes:

a) increased tissue hydrophilicity, decreased diuresis, impaired water-salt metabolism;

b) increased diuresis and rapid removal of water from the body;

c) decrease in blood pressure;

9. Electromagnetic fields affect primarily:

a) on the nervous and immune systems;

b) on the excretory and genitourinary systems;

c) on the musculoskeletal system;

d) on the senses and digestive system.

10. The infamous Minamata disease (accompanied by loss of vision and hearing), discovered in Japan, was caused by:

a) high cobalt content in food;

b) high mercury content in food;

c) lack of microelements in food;

d) excess magnesium, sodium and copper in food

11. Plants that synthesize special substances - phytoncides, stimulating the absorption of ascorbic acid and enhancing regenerative processes in tissues include:

b) peppermint;

c) coniferous species;

d) deciduous trees

12. Modern environmental and demographic problems arose due to:

a) increasing the settled population of the world;

b) population migration to cities and developed countries;

c) population migration to rural areas;

d) increasing the number of small settlements

Fill in the blanks in the text

13. Ecosystem development comes from _____________________________________________

to _________________________________ state

14. Stable stages of development of biocenoses are also called ____________________________________ stages.

15. Organisms living in soil are called ________________________________

16. The biomass of each subsequent link in the food chain progressively decreases - so says ___________________________________________________________________

17. Increased sensitivity of the body to the effects of a number of environmental factors, called _____________________________________, manifests itself in the form of _____________________________________________________________________.

18. A disease that leads to obesity with low mobility, especially often occurs in urban conditions and is called _____________________________________________________.

Find the matches and write down the correct answers (a, b, c,...)

19. Ecosystems:

1) more autonomous; 2) less autonomous;

Examples: a) forest; b) river; c) meadow; d) steppe; e) lake; e) a site on a steep mountain slope.

Answers: 1) ___________________________ 2) ____________________________ .

20. Selective accumulation of radioactive substances by organs and tissues:

1) thyroid gland;

2) bone tissue;

3) spleen and liver

4) light

Examples of substances: a) radon; b) iodine; c) polonium; d) radium

Answers:

21. Medicinal plants used in herbal medicine:

1) foxglove;

2) primrose officinalis;

3) sandy immortelle;

4) great celandine

Application: a) removal of warts, choleretic agent; b) an expectorant for colds and lung diseases (contains a lot of vitamin C); c) treatment of the cardiovascular system; d) treatment of liver and kidney diseases

1) ________________________ ; 2) __________________________;

3) _________________________; 4) __________________________

Educational project “I explore the world”

XVI Republican correspondence Olympiad for schoolchildren in biology, ecology, chemistry and geography

60 years

RDEBC

2006

Grade 10

Cipher
Job No.	1	2	3	4		5	6	7	Sum
points Max.
	6	6	7	7		10	4	10	50

Task No. 1. Calculate the amount of heat that will be released during the decomposition of ammonium dichromate if the reaction results in the formation of 5.6 g of nitrogen. The heats of formation of (NH4)2Cr2O7, Cr2O3 and H2O are 1808, 1141, and 286 kJ/mol, respectively.

^ Task No. 2. Determine the possible structural formula and name of an alkane if it is known that the number of bonds between carbon atoms in it is three times less than the number of bonds between carbon and hydrogen atoms, and its chlorination leads to only one monochlorine derivative. Write an equation for the reaction of alkane chlorination. Name the reaction product

Answer: ___________________________________________________________________________________________

__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
^ Task No. 3. After passing 8.96 l (n.s.) of a mixture of ethane and acetylene into an excess of ammonia solution of silver oxide, 72 g of a precipitate were obtained. Calculate the mass fractions of gases in the original mixture.

__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
^ Task No. 4. A mixture of calcium carbide and calcium nitride was dissolved in water, and a gas 9.4 times heavier than hydrogen was released. Determine the mass fraction of carbide in the initial mixture.

Answer ___________________________________________________________________________________________

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Task No. 5. A gas mixture weighing 24.0 g and volume 14.76 l (27ºС, 1 atm), consisting of ethane and an unknown gas, the volume fraction of which is 25%, was passed through an aqueous solution of potassium permanganate. Determine the mass of the deposited sediment

Answer ___________________________________________________________________________________________

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Task No. 6. Three test tubes without labels contain aqueous solutions of nitric acid, ammonium nitrate and silver nitrate. How can one distinguish between these solutions using one reagent? Write the reaction equations and indicate their characteristics

Answer ___________________________________________________________________________________________

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Task No. 7. Phosphorus obtained from 46.5 g of calcium phosphate was burned in excess oxygen and 295.5 ml of an 8% sodium hydroxide solution with a density of 1.1 g/ml was added to the resulting combustion product. Determine the composition of the resulting solution in mass fractions

Answer ___________________________________________________________________________________________

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