CHEMISTRY OF GUNPOWDER

Gunpowder is a mixture of potassium nitrate, carbon, and sulfur. Since it is a mixture, it does not, strictly speaking, have a formula. The standard composition for black powder (i.e, Proportions by weight) are 75%potassium nitrate , 15% Carbon, and 10% sulfur.

Sulfur's main role in gunpowder is to decrease the ignition temperature. A sample reaction for sulfur-free gunpowder would be

6 KNO3 + C7H4O → 3 K2CO3 + 4 CO2 + 2 H2O + 3 N2.

With the Fourth of July and American Independence Day on the horizon, a somehow topical post seemed in order. Having already examined the chemical compounds that give fireworks their colours . I decided to examine another important firework component here: the first chemical explosive, gunpowder, also commonly referred to as black powder.
Until the mid-19th Century, gunpowder was the only known chemical explosive. Its use can be traced much earlier than this, however, and there are historical accounts of its use in fireworks in China as far back as 1200AD. In subsequent centuries it had military applications in rifles and cannons, but in these it has long since been replaced by modern, smokeless powders. The fireworks industry is one of the last major industries that still uses traditional black powder.

Rather than being one particular compound, gunpowder is actually a mix of three different components. It consists of potassium nitrate (75% by weight), charcoal (15% by weight), and sulfur (10% by weight). Each of these components plays an important role in the combustion of gunpowder.

Potassium nitrate, also known as ‘saltpetre’, or ‘saltpeter’, decomposes at high temperature to provide oxygen for the reaction. This means that gunpowder doesn’t need to be exposed to air to burn – and is why smothering fireworks won’t stop them burning! The charcoal is often represented simply as being a source of carbon, which acts as a fuel, though it’s actually a broken down form of cellulose, with the approximate empirical formula C7H4O. Finally, the sulfur can also act as a fuel, though its inclusion has more to do with the fact that it undergoes exothermic reactions (reactions that give off heat) at relatively low temperatures, providing more energy and lowering the ignition temperature of the charcoal.
It’s worth noting that just mixing these three constituents together isn’t enough to produce good quality gunpowder; they must be thoroughly mixed, moistened and ground to produce a reactive mixture. Deviations from the ideal ratio given above are sometimes utilised to alter the burning behaviour of the mixture, and the addition of small amounts of water to the mixture can also be used to extend the burning time.
The precise reactions of gunpowder are difficult to elucidate. Rather than being a simple single reaction, the combustion of gunpowder consists of many differing complex reactions. It’s possible, however, to provide simplified equation that provides an overall idea of the products of the various reactions, as shown in the graphic. A mixture of solid and gaseous products are produced by the reactions, along with a very small amount of water.
The obvious use for black powder in firework is as the ‘lift charge’, which propels the firework into the air. The fuse, which allows the delay before the bursting of the firework, and the bursting charge itself, will also utilise gunpowder. The burning of the charcoal in gunpowder is often the source of the sparkling tails of fireworks as they ascend. The gases produced by the combustion reaction are the causes of the propellant effect, and the eventual bursting of the firework.

List of reagents in organic chemistry

Hii everyone I am going share some idea about how many reagents are present in organic chemistry based on current data which I have  so let see, first I am going to tell you what is reagents?
So Reagents are "substances or compounds that are added to a system in order to bring about a chemical reaction or are added to see if a reaction occurs.Some reagents are just a single element. However, most processes require reagents made of chemical compound Some of the most common ones.
Types of reagents ;

Acetic acid: an organic acid is one of the simplest carboxylic acid . systematically named ethanoic acid is a colourless liquid organic compound with the chemical formula CH₃COOH (also written as CH₃CO₂H or C₂H₄O₂). When undiluted, it is sometimes called glacial acetic acid. Vingar is no less than 4% acetic acid by volume, making acetic acid the main component of vinegar apart from water. Acetic acid has a distinctive sour taste and pungent smell. In addition to household vinegar, it is mainly produced as a precursor to polyvinyl acetate and cellulose acetate It is classified as a weak acid  only partially dissociated in solution, but concentrated acetic acid is corrosive and can attack the skin.
This acid is an important chemical reagent and industrial chemical useful for the production of various synthetic fibers and other polymeric materials. These polymers include polyethylene terephthalate, used mainly in soft drink bottles; cellulose acetate used mainly for photographic film; and polyvinyl acetate, for wood glue. In households, diluted acetic acid is often used in descaling agents. The food industry uses it (under the food additive code E260) as an acidity regulator.

Acetone ;  an  organic compound with the formula (CH₃)₂CO. It is a colorless, volatile, flammable liquid and is the simplest and smallest ketone.

Acetone is misible with water and serves as an important solvent in its own right, typically for cleaning purposes in laboratories. About 6.7million tonnes were produced worldwide in 2010, mainly for use as a solvent . It is a common building block in organic chemistry Familiar household uses of acetone are as the active ingredient in nail polish remover and as paint thinner.Acetone is produced and disposed of in the human body through normal metabolic processes. It is normally present in blood and urine.

Acetylene;( systematic name Ethyne ) is the chemical compound with the formula C₂H₂. It is a hydrocarbon and the simplest alkyne.this is colorless gas is widely used as a fuel and a chemical building block. It is unstable in its pure form and thus is usually handled as a solution. pure acetylene is odorless, but commercial grades usually have a marked odor due to impurities.

As an alkyne, acetylene is unsaturated because its two carbon atoms are bonded together in a triple bond  The carbon–carbon triple bond places all four atoms in the same straight line, with CCH bond angles of 180°.
Ammonia : 
 Compound of nitrogen and hydrogen with the formula NH3 The simplest pnictogen hydride ammonia is a colourless gas with a characteristic pungent smell. It is a common nitrogenous west particularly among aquatic organisms, and it contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food fertilizer. Ammonia, either directly or indirectly, is also a building block for the synthesis of many pharmaceutical  compound and is used in many commercial cleaning products. It is mainly collected by downward displacement of both air and water. Ammonia is named for the Ammonians, worshipers of the Egyptian god Amun who used ammonium chloride in their rituals.

Ammonium hydroxide: 
 also known as ammonia water, ammonia solution, ammoniacal liquor, ammonia liquor, aqua ammonia, aqueous ammonia, or (inaccurately) ammonia, is a solution of ammonia in water. It can be denoted by the symbols NH₃(aq). Although the name ammonium hydroxide suggests an alkali with composition [NH₄⁺][OH⁻], it is actually impossible to isolate samples of NH₄OH. The ions NH₄⁺ and OH⁻ do not account for a significant fraction of the total amount of ammonia except in extremely dilute solutions.

Azobisisobutyronitrile (abbreviated AIBN): is an organic compound with the formula [(CH₃)₂C(CN)]₂N₂. This white powder is soluble in alcohols and common organic solvents but is insoluble in water. It is often used as a foamer in plastic and rubber and as a radical initiators.


Baeyer's reagents : is an alkaline solution of potassium permanganate; used in organic chemistry as a qualitative test for the presence of unsaturation, such as double bonds.

World's fastest hydrogen sensors

Hii everyone I am going to share some important things on hydrogen as sensors how it can help for us and how it is work its most important part because we all know hydrogen is present very large amount so we can use for so many thing .
 So sensors hydrogen is good thing for current world let see how it work
Credit; a Ph.D. student Ferry Nugroho and his supervisor Christoph Langhamme.

Hydrogen is a clean and renewable energy carrier that can power vehicles, with water as the only emission. Unfortunately, hydrogen gas is highly flammable when mixed with air, so very efficient and effective sensors are needed. Now, researchers from Chalmers University of Technology, Sweden, present the first hydrogen sensors ever to meet the future performance targets for use in hydrogen powered vehicles.

The researchers' ground-breaking results were recently published in the prestigious scientific journal Nature Materials. The discovery is an optical nanosensor encapsulated in a plastic material. The sensor works based on an optical phenomenon – a plasmon – which occurs when metal nanoparticles are illuminated and capture visible light. The sensor simply changes colour when the amount of hydrogen in the environment changes.

The plastic around the tiny sensor is not just for protection, but functions as a key component. It increases the sensor's response time by accelerating the uptake of the hydrogen gas molecules into the metal particles where they can be detected. At the same time, the plastic acts as an effective barrier to the environment, preventing any other molecules from entering and deactivating the sensor. The sensor can therefore work both highly efficiently and undisturbed, enabling it to meet the rigorous demands of the automotive industry – to be capable of detecting 0.1 percent hydrogen in the air in less than a second.

"We have not only developed the world's fastest hydrogen sensor, but also a sensor that is stable over time and does not deactivate. Unlike today's hydrogen sensors,our solution does not need to be recalibrated as often, as it is protected by the plastic," says Ferry Nugroho, a researcher at the Department of Physics at Chalmers.

It was during his time as a Ph.D. student that Ferry Nugroho and his supervisor Christoph Langhammer realised that they were on to something big. After reading a scientific article stating that no one had yet succeeded in achieving the strict response time requirements imposed on hydrogen sensors for future hydrogen cars, they tested their own sensor. They realised that they were only one second from the target – without even trying to optimise it. The plastic, originally intended primarily as a barrier, did the job better than they could have imagined, by also making the sensor faster. The discovery led to an intense period of experimental and theoretical work.

In that situation, there was no stopping us. We wanted to find the ultimate combination of nanoparticles and plastic, understand how they worked together and what made it so fast. Our hard work yielded results. Within just a few months, we achieved the required response time as well as the basic theoretical understanding of what facilitates it," says Ferry Nugroho.

Detecting hydrogen is challenging in many ways. The gas is invisible and odourless, but volatile and extremely flammable. It requires only four percent hydrogen in the air to produce oxyhydrogen gas, sometimes known as knallgas, which ignites at the smallest spark. In order for hydrogen cars and the associated infrastructure of the future to be sufficiently safe, it must therefore be possible to detect extremely small amounts of hydrogen in the air. The sensors need to be quick enough that leaks can be rapidly detected before a fire occurs.

"It feels great to be presenting a sensor that can hopefully be a part of a major breakthrough for hydrogen-powered vehicles. The interest we see in the fuel cell industry is inspiring," says Christoph Langhammer, Professor at Chalmers Department of Physics.

Although the aim is primarily to use hydrogen as an energy carrier, the sensor also presents other possibilities. Highly efficient hydrogen sensors are needed in the electricity network industry, the chemical and nuclear power industry, and can also help improve medical diagnostics.

"The amount of hydrogen gas in our breath can provide answers to, for example, inflammations and food intolerances. We hope that our results can be used on a broad front. This is so much more than a scientific publication," says Christoph Langhammer.

In the long run, the hope is that the sensor can be manufactured in series in an efficient manner, for example using 3-D printer technology.

Facts: The world's fastest hydrogen sensor

• The Chalmers-developed sensor is based on an optical phenomenon – a plasmon – which occurs when metal nanoparticles are illuminated and capture light of a certain wavelength.
• The optical nanosensor contains millions of metal nanoparticles of a palladium-gold alloy, a material which is known for its sponge-like ability to absorb large amounts of hydrogen. The plasmon effect then causes the sensor to change colour when the amount of hydrogen in the environment changes.
• The plastic around the sensor is not only a protection, but also increases the sensor's response time by facilitating hydrogen molecules to penetrate the metal particles more quickly and thus be detected more rapidly. At the same time, the plastic acts as an effective barrier to the environment because no other molecules than hydrogen can reach the nanoparticles, which prevents deactivation.
• The efficiency of the sensor means that it can meet the strict performance targets set by the automotive industry for application in hydrogen vehicles of the future by being capable of detecting 0.1 percent hydrogen in the air in less than one second.
• The research was funded by the Swedish Foundation for Strategic Research, within the framework of the Plastic Plasmonics project.