Why does a candle produce water when it burns, and what does a candle produce when it burns?

Hehe, candles are carbohydrates, that is, (CH2O)N, the main ingredient of candles is oil, and it is normal to produce water, the composition of candles and their combustion products, candles are usually made of paraffin. Paraffin wax is produced from the waxy fraction of petroleum by cold pressing or solvent dewaxing. Paraffin is a mixture of several higher alkanes, mainly n-dodosecane (C22H46) and n-octadecane (C28H58), containing about 85 carbon elements and 14 hydrogen elements.

Stearic acid (C17H35COOH) is also often added to candles to improve softness.

When the candle burns, the products of the combustion of n-docosane and stearic acid are carbon dioxide and water. The chemical equation for the reaction is as follows:

2c22h46 + 67o244co2 + 46h2oc17h35cooh + 26o218co2 + 18h2o

Because the candle is composed of paraffin wax, which contains hydrogen, according to the law of conservation of mass, the candle burns and reacts with oxygen in the air to form water.

This is the conclusion of experiments, which cover a burning candle with a dry, cold beaker with a mist of water on the inner wall of the beaker. So generate water. I wonder if the burning of the candle heats the air above, and the hot air meets the cold beaker and liquefies into water.

When the candle is burned, it produces: carbon dioxide and water.

Verification: Light the candle, cover a cold and dry beaker over the candle for 5 minutes, quickly invert the beaker, and find that the inner wall of the beaker becomes blurred and water droplets are generated, indicating that the candle burns to produce water.

A small amount of clarified lime water was added to the beaker and shaken, and it was observed that the clarified lime water became turbid, indicating that the candle burned to produce carbon dioxide.

The main component of the candle is carbon oxides, which react with oxygen in the air during combustion to produce water and carbon dioxide. The flame of a candle is divided into three parts, which are divided into the outer flame, the inner flame, and the flame center. The outer flame temperature is the highest, the flame core temperature is the lowest, and the inner flame is the brightest.

Nature of the candle:

The main raw material of candles is paraffin wax (CH) Paraffin wax is prepared from the wax-containing fraction of petroleum by cold pressing or solvent dewaxing, which is a mixture of several high-grade alkanes, mainly n-docosane (C22H46) and n-octadecane (C28H58), containing about 85% carbon and 14% hydrogen. The added excipients are white oil, stearic acid, polyethylene, flavor, etc., among which stearic acid (C17H35COOH) is mainly used to improve softness, and the specific addition depends on what kind of candle is produced.

It is easy to melt, the density is less than that of water, and it is difficult to dissolve in water. It melts into a liquid state when heated, colorless, transparent and slightly volatile when heated, and can smell the unique odor of paraffin. When cold, it solidifies into a white solid form with a slight special odor.

The candle does not go out when placed in water because there is a thin layer of candle around the flame of the candle. The reason for this layer is that the water freezes the wax on the outer layer of the candle so that it will not be extinguished at the edge of the fire. It is better to do this experiment in windless, cold weather, which will be easier to succeed.

Candles: Candles are an everyday lighting tool made primarily from paraffin wax, and in ancient times, were often made from animal fat. Combustible glows.

In addition, candles are used in a wide range of applications: they are also used in birthday parties, religious festivals, mass mourning, ceremonies, and other events. In literary and artistic works, Qin Xuan candles have symbolic meanings of sacrifice and dedication.

In modern times, it is generally believed that candles originated from torches in primitive times, when primitive people applied fat or wax to the bark or wood chips, tied the bark together, and made torches for lighting. There is also a legend that in the pre-Qin and ancient periods, some people tied mugwort and reeds into a bunch, and then dipped some grease and lit them for lighting.

Because the candle liquid is hot and the water is cold, the water will freeze the outer layer of the candle to make the wax, forming a thin layer of candle around the pure dust flame of the candle, preventing the water from entering the wax tank to the cotton core, so the candle will not go out. The main raw material for candles is paraffin, which is made from the wax-containing fraction of petroleum by cold pressing or solvent dewaxing. Candles melt easily, are less dense than water and are poorly soluble in water.

The candle will melt into a liquid state when heated, colorless and transparent, volatile when slightly heated, and has a special smell of paraffin. The candle solidifies into a white solid collapse when condensed, and has a slight special smell.

Candle burning is not the burning of paraffin solids, but the ignition device ignites the cotton wick, and the heat released melts the paraffin solids and revaporizes them to produce combustible paraffin vapor.

It is because the water isolates the candle from the air, so the candle will not be extinguished when placed in the water.

Preparation materials for candles burning in water: a box of matches, a glass, a candle, some water inside the candle to light the candle, and fix the candle at the bottom of the glass in the same way**. Then carefully fill the glass with water 1 cm from the top of the candle.

Doing my observations, I found that when the candle burned close to the surface of the water, the candle did not go out.

Continuing to observe, I noticed that a thin cylindrical wall had formed around the burning groove of the candle. The wick of the candle has reached below the surface of the water. It turns out that because the candle liquid is hot and the water is cold, when they meet, they form a circular protective layer around the candle (that is, the column-like wall we see).

Stop the water from entering the wax trough to the wick, the candle will not go out, and we will see the candle burning in the water.

You first have to have a longer candle, preferably new. Find another bucket that is taller than the candle. After lighting the candle, stick it to the bottom of the bucket and slowly drain the water down the walls of the bucket.

until the water is a little lower than the candle. Remember to put it on the ground at a level! Don't touch it again.

Let it burn slowly. Then you'll find that the flame won't be extinguished even below the surface of the water. Because there is a thin layer of candle around the flame of the candle, it is it that blocks the water and extinguishes the fire.

The reason for this layer is that the water freezes the wax on the outer layer of the candle so that it will not be extinguished by the fire. It is better to do this experiment in windless and cold weather, so that it will be easier to succeed!

Of course, the fire will not be extinguished if it is placed outside the water, but it will be extinguished if the flame is put in the water.

Because the candle can float on the water, it can continue to burn as long as it is not extinguished.

This is because the specific gravity of wax is less than that of water and is always floating on the surface of the water.

In the process of burning, the candle undergoes both physical and chemical changes, the candle melts into a liquid state, and then into a gaseous state, so a physical change occurs, and then the candle reacts with oxygen to produce carbon dioxide.

This produces a new substance that conforms to a chemical reaction.

There are two processes in wax combustion: melting by heat and forming other substances.

1. Melting of wax when heated is a physical phenomenon.

2. The combustion of wax to produce water and carbon dioxide is a chemical reaction.

3. Wax combustion is a chemical reaction that is first heated and melted, and when the flammable temperature is reached, other substances are generated.

Experiments have shown that after the candle is burned, it does not "burn off", it only turns into two other substances - water and carbon dioxide.

Scientists carefully studied the burning process of candles, and they found that the weight of water and carbon dioxide produced after the candle was burned was equal to the total weight of oxygen in the air consumed by the candle and the candle when it was burned.

When a candle burns, the products of combustion are carbon dioxide and water. Chemical expressions.

C25H52+O2 (ignition) CO2+H2O.

in oxygen cylinders. The combustion phenomenon is that the flame is bright and emits white light, emitting heat, and there is a mist of water on the wall of the bottle.

Simple proof experiment:

Light the candle and cover it with a cold, dry beaker over the candle.

After 5 minutes, the beaker was quickly inverted, and it was found that the inner wall of the beaker was blurred and water droplets were formed, indicating that the candle was burning to produce water.

Add a small amount of clarified lime water to the beaker.

Oscillation, observed to clear lime water to become turbid, indicating that the candle burns to produce carbon dioxide.

Candles under the surface of the water can continue to burn, because the wax that melts during the burning process of the candle will quickly turn solid when it encounters water and freeze around the fire Senki flame. However, when the flame is below the surface of the water, the water will quickly carry away the heat that is forcing on the wax cylinder, so the wax cylinder can protect the flame from burning.

Water plays a key cooling role so that candles close to the water do not melt due to the burning of the wick, so that the water is separated by the unburned wax layer, protecting the candle in the middle from continuing to burn until it reaches the bottom of the cup.

Place the plate on the table and fill the plate with a small amount of water. Light the paper and quickly stuff it into the glass, then immediately place the rim downside down on the plate. As the fire is extinguished, the cup is like a thirsty and smoking throat, "drinking" the water in the plate, and the water that enters the cup will not flow out again.

If you put a coin under the water in the bottom of the plate, you can take it out without getting your fingers wet. Of course, when buckle the cup, be careful not to cover the coin with the rim. Be careful not to put too much water in the dish, otherwise the cup may not be able to drink the water in the dish.