Chemistryy by Tang Beavan

How does instant ice packs work

nafrizzi — 2017-04-20 09:54:07 UTC

They work by having a smaller bag inside containing ammonium nitrate or calcium ammonium nitrate. The bigger bag surrounding it, contains water. When the smaller bag is broken (by squeezing the bag), the water is allowed to dissolve with the solid, causing an endothermic reaction. This reaction absorbs heat from the surroundings, lowering the bag's temperature, making it cold without the need of ice!

For further reading : http://www.ehow.com/how-does_4925771_instant-ice-packs-work.html

It is relevant for the chapter Thermochemistry! Thermochemistry studies the relationship between heat and chemical reactions. In this case, the reaction results in heat being absorbed from the surroundings and the pack becoming cold

How does baking powder make baked goods rise?

charmian13 — 2017-04-20 14:30:07 UTC

Baking powder contains sodium bicarbonate (NaHCO₃, also known as baking soda) which is alkaline and potassium bitartrarte (KC₄H₅O₆, also known as cream of tartar) which is acidic. When baking powder is added to batter which contains water, the baking soda and cream of tartar dissolve and react together to release carbon dioxide in a process which can be illustrated in the following chemical equation: NaHCO₃ + KHC₄H₄O₆ → KNaC₄H₄O₆ + H₂O + CO₂. This is useful to turn baked goods from a chewy and dense mass of flavoured flour to a light, fluffy and airy network filled with gas bubbles that you can bite through easily.

For further reading: https://www.thoughtco.com/how-baking-powder-works-607382

This is relevant to the chapter 'Acids and Bases' where we study the reactions and products between the many acids and bases.

How does strong acid such as sulfuric acid damage and burn our skin?

2017-04-21 09:19:44 UTC

The corrosive acid will react with the skin by hydrolyzing the fats and proteins in the skin. The strong acid denatures proteins and fats in the living tissues and hydrates them. This removes water from the living tissues in which the the acid reacts with the water and ionizes ,causing an exothermic reaction which releases large amounts of heat. This explains why it would feel warm initially when it comes into contact with the skin before the temperature rises up rapidly as more water reacts with the acid thus producing more heat. Instantaneously, the intense heat will in turn damage or kill cells deeper into the skin.

For further reading : https://www.quora.com/How-does-acid-damage-the-skin-biochemically-speaking

This is relevant to our module as there will be some practicals which involves the use of acids. Therefore, knowing how strong acid can burn our skin will enable us to understand the reason behind safety precautions such as wearing gloves in the lab and encourage us to be more careful when handling such acids.

The question is also relevant for the chapter "Acids and Bases" as it shows the corrosive property of acid and the chapter of "Redox Reactions" as the reaction between acid and water from our skin is an exothermic reaction which releases heat.

Uses of chemistry in cooking?

clonezinx — 2017-04-21 14:55:07 UTC

Cooking in itself involves a lot of chemistry, such as physical and chemical changes that ingredients undergo to become the dishes to be served, or specific chemical reactions to form a certain taste. One method of cooking, called Molecular Gastronomy however uses more advanced chemistry techniques to create dishes.
The definition of Molecular Gastronomy is the application of scientific principles to the understanding and development of food preparation.
An example of molecular gastronomy is Spherification - a simple gelling reaction between calcium chloride and alginate

When sodium alginate (a polymer) is placed in a solution of calcium ions, the calcium ions

replace the sodium ions in the polymer. Each calcium ion attaches to the polymer strands (called cross linking) (ref. below)

This culinary technique makes use of this reaction to shape liquids into caviar like spheres. These spheres are filled with ingredients such as orange juice to be mixed with cocktails and other dishes.
For further reading:
http://splice-bio.com/molecular-gastronomy-the-food-science/
https://www.chemistryworld.com/news/cooking-with-chemistry/3001121.article

This is relevant to the chapters of Chemical reactions and Chemical Bonding. A chemical bond is a lasting attraction between atoms that forms chemical compounds, much like the bonds in spherification, and such bonds are formed after a chemical reaction between the two reagents.

Why do we need to condition our hair after we shampoo it?

cheyenne_kohqien — 2017-04-22 03:10:51 UTC

Our hair’s original pH level is 4.5 to 5.5. Each strand of hair is surrounded by cuticle scales which lay flat when the hair is at its healthy, normal acidic level. Since shampoos tend to be alkaline due to the cost-related poor ingredients used, the hair cuticles will rise up, causing your hair to be tangled and frizzy. Therefore, we need conditioners, which are acidic, to bring back the original pH level of the hair. When the hair is acidic, the cuticles lay flat which retains moisture and results in non-frizzy and mosturised looking hair. Thus, reducing any tangles in our hair, giving off a ‘shiny’ and non-frizzy appearance.

This is related to our module, as this is under the topic of acids and bases. During our lessons, we will learn the reaction between acids and bases and the reaction between the shampoo and conditioner is a simple example of how the acidic and alkaline levels play a part in our daily lives.

For further reading: https://www.quora.com/Why-is-hair-conditioner-acidic

Photo source: http://1.bp.blogspot.com/_GkQ08Dsvo30/TBeVp1CwIMI/AAAAAAAAAn4/3KYStQdg2VU/w1200-h630-p-nu/stepheight.png

Solubility

yingtong_soo — 2017-04-22 05:35:28 UTC

Why is it that when too much milo powder is added to a fixed volume of water, and no matter how much stirring is done, there are still remnants of undissolved milo powder?

This is due to the concept of solubility. When a solid is added slowly to pure water, it dissolves initially until it reaches a point where no more solid can dissolve. This also means that the solution is saturated.

A saturated solution refers to a chemical solution containing the maximum concentration of a solute dissolved in the solvent. Additional solute will not dissolve in a saturated solution.

However, if we were to add the same amount of milo powder to a higher temperature of water, the milo powder might dissolve even in the same volume of water. This shows that factors are involved in solubility of a mixture, be it solids in liquids, or liquids in liquids.

This is relevant as we will be covering on the topic of solubility and this can also be linked to the factors that affects solubility, such as the surface area and temperature of the solute. We will also be able to determine if a salt will be completely soluble in a solvent by looking at its solubility and the solubility product. The chemical nature of the solute will also play a part in the solubility of a product. Some solutes are also insparingly soluble, which explains why they just don't dissolve.

For further reading:

https://chem.libretexts.org/Textbook_Maps/General_Chemistry_Textbook_Maps/Map%3A_Chemistry%3A_The_Central_Science_(Brown_et_al.)/13%3A_Properties_of_Solutions/13.2%3A_Saturated_Solutions_and_Solubility

Why do copper wires conduct electricity well? (Chemical Bonding- Metallic Bonds)

booyahowned — 2017-04-22 11:09:11 UTC

Metal atoms are held strongly together to each other by metallic bonds to form a giant lattice structure.

In this lattice, metal atoms lose their outermost(valance) electrons and form positively charged ions(cations) to achieve stable electronic configurations.

Their outermost electrons no longer belong to any metal atom and are ‘delocalised’. Thus, this ‘sea of delocalized mobile electrons’ can move freely between metal ions to carry electrical charge. Hence, metals such as copper are good conductors of electricity and can be used as wires.

For further reading: http://www.edinformatics.com/math_science/why_metals_conduct.htm

This is relevant to the topic of Chemical Bonding as it involves metallic bonding, which is the force of attraction between positively charged metal cations and the negatively charged ‘sea of delocalized mobile electrons’.

How Do Safety Matchsticks Light Up?

amirayeo — 2017-04-22 11:17:07 UTC

A common misconception is that people think that only friction will cause a matchstick to light up. However, are you aware that a chemical reaction is involved?

A safety matchstick is made up of a strong oxidising agent, Potassium Chlorate (KClO₃) and a powerful reducing agent, Antimony Trisulfide (Sb₂S₃). The wooden part contains Ammonium Phosphate ((NH₄)₃PO₄ ), which suppresses the afterglow when the flame burns out. The striking surface consists of red Phosphorus. Phosphorus is a necessary component for the ignition process.

Striking the matchstick against the surface creates friction which causes Potassium Chlorate and the red Phosphorus to react. The red Phosphorus changes to white due to heat from friction. The volatile white Phosphorus then produces a flame because it ignites immediately. Furthermore, Oxygen in the air keeps the flame alive by fuelling it. Antimony Trisulfide is oxidised to Antimony Trioxide (Sb₂O₃), and Sulfur Dioxide (SO₂). Also, Potassium Chlorate is reduced to Potassium Chloride (KCl). Heat produced by Phosphorus decomposes Potassium Chlorate and this releases Oxygen. Sulfur is combined with this oxygen to keep the flame lit.

The chemical equation of lighting a safety matchstick is given by:
3KClO₃ + Sb₂S₃ --> 3KCl + Sb₂O₃ + 3SO₂

For further reading on Safety Matchsticks: https://www.quora.com/What-is-the-reaction-involved-in-lighting-a-matchstick and https://www.slideshare.net/ayesca/matchespptx1pptx2

This is relevant because we will be studying Chemical Reactions involving Chemical Equations, reactants and products. Redox reaction is also included in one of our lab session.

How does toothpaste prevent tooth decay?

nhnicholasho2000 — 2017-04-22 11:40:30 UTC

When we use toothpaste, it helps to neutralize the acids in our mouths as it acts as a base. One of the active ingredients found in toothpaste is Sodium Fluoride (NaF). The presence of fluoride in toothpaste is the primary reason why the use of toothpaste aids in the prevention of tooth decay or dental caries which is the breakdown of teeth as a result of bacteria. Tooth enamel which is found on our teeth acts as a barrier that helps to protect our teeth from decaying, however, it is vulnerable and susceptible to acid attacks due to bacterial plaque. Tooth enamel is primarily made up of a mineral called hydroxyapatite Ca10(PO4)6(OH)2. Overtime, the minerals found in tooth enamel are dissolved when acid-producing bacteria found in dental plaque erodes away the enamel on our teeth, leading to cavity when demineralization (a process by which minerals are removed from enamel) occurs more often than remineralization of the teeth. However, by using toothpaste, fluoride ions found in toothpaste bind with hydroxyapatite in the tooth enamel to form a stronger barrier called fluorapatite Ca10(PO4)6F2.

Ca10(PO4)6(OH)2 + 2F- -> Ca10(PO4)6F2 + 20H-

The presence of fluorapatite inhibits tooth decay, making the tooth structure more acid-resistant to caries attack. This helps to prevent tooth decay as a result.

For further reading: https://en.m.wikipedia.org/wiki/Remineralisation_of_teeth

https://www.thoughtco.com/how-fluoride-works-prevent-tooth-decay-607857

This is relevant to the topics on ‘Acids and Bases’ and ‘Chemical Reactions’ as we will be learning about neutralization of acids and how certain chemicals react in a certain way to form a new product.

How do oxidising agents work as disinfectants?

hafizin55 — 2017-04-22 14:47:46 UTC

Disinfectants are anti-microbial agents. They are used to destroy, or inhibit the growth of micro-organisms living on the surface of non-living objects. One example of such chemicals is the well-known CLOROX bleach, a common disinfectant that can be found in many household kitchens.

But how do they work???

Sodium hypochlorite (NaClO), the main active ingredient in bleach, is a strong oxidising agent, and has the ability to cause other substances to lose electrons (to be oxidised). When bleach is thus applied to a surface, bacterial molecules lose their electrons which disrupts their cell structure, leading to their death – which is how these types of disinfectants are able to eradicate micro-organisms in large quantities.

But what is oxidation and its other related phenomena? To explain this, we can refer to a simpler chemical, but with roughly the same areas of usage and application – hydrogen peroxide.

Hydrogen peroxide (H₂O₂) is another oxidising agent, which is a disinfectant commonly used for the sterilisation of medical equipment. Let us take a glance at its electronic structure, or rather (due to technical difficulties), its structural formula;

H-O-O-H

This compound seems stable as each oxygen atom is bonded to two other atoms covalently. But is it really the case? Let us look at the two elements that form hydrogen peroxide;

o Hydrogen atoms, with an oxidation state of +1

o Oxygen atoms, with an oxidation state of -1

Hydrogen peroxide has an oxidation state of 0.

The oxidation state of oxygen in hydrogen peroxide is unstable – it is only stable at numbers -2 and 0, where oxygen would be in the compounds H₂O and O₂respectively. Thus, hydrogen peroxide would decompose to form water and/or oxygen gas;

2H₂O₂ --> 2H₂O + O₂

As mentioned earlier, oxidising agents can cause other substances to lose electrons. This is the half equation for which hydrogen peroxide gains electrons from another substance;

H₂O₂ + 2e^- --> 2OH^-

Read up more on: https://www.quora.com/Why-does-the-extra-oxygen-atom-in-hydrogen-peroxide-H2O2-make-it-an-antiseptic-while-water-H2O-is-not-antiseptic

This is relevant to the topics Electronic Structure and Redox Reactions, as we assess the properties of chemicals with respect to – you guessed it – their structure. We can ponder upon the effects of minor differences of the composition of the compound, and explore one of many common uses of redox reactions in modern life.

"Man cleaning table in the kitchen" - Shutterstock

How Nuclear Plant works?

2017-04-23 02:46:39 UTC

In summary, nuclear plants make use of energy released during atom splitting to generate electricity. Uranium-235 is often used as a nuclear fuel as it is an unstable element in which the forces inside the nucleus are unbalanced, hence it splits or fission more easily, making it an ideal fuel. Inside the reactor core, neutrons from the neutron source bombards the Uranium-235 atoms resulting in Nuclear Fission.

In most cases, the reactions causes Uranium-235's nucleus to break up and split into 2 nuclei, along with neutrons being released. The difference in mass between the original reactant and products is converted into energy( Einstein's E=MC^2). The released neutrons would then collide with other Uranium-235 atoms causing them to split, resulting in a Chain Reaction, releasing large amount of energy.

The energy released from the chain reaction is used to boil water to steam which drive turbines, generating electricity. In a nutshell, nuclear plants generate clean energy without the release of greenhouse gases.

Want to know more? http://www.explainthatstuff.com/how-nuclear-power-plants-work.html

This is relevant to the module "Nuclear Chemistry" where we learn about radioactivity and the use of radioactive material for different purposes and processes.

Image: http://www.atomicarchive.com/Fission/Fission1.shtml

How is electronegativity relevant in our everyday lives?

2017-04-23 05:18:42 UTC

Why do farmers add lime to the soil where their crops are grown?

2017-04-23 05:44:51 UTC

This is because soil can be acidic due to impurities present or acid rain.

Why do Farmers add lime to the soil where their crops are grown?

nithillap — 2017-04-23 05:52:37 UTC

Sometimes soil can have a low pH value, and the soil can be acidic due to impurities or acid rain. This is not optimal for plant growth, hence lime is added. Lime (CaO) is alkaline in nature, and it has a higher pH. This will result in a chemical reaction known as neutralization, which results in the soil having a pH more optimal for plant growth.

This is relevant to the topic of acids and bases as it explores the use of reactions involving such substances. We will learn about how acids and bases can be used to complement each other and how they can be applied in the real world. It also teaches us the importance of learning about pH values.

For further reading:
http://encap.net/why-add-lime-to-soil/

Photo: https://emswcd.org/farm-incubator/headwaters-farm/photo-galleries/headwaters/9-27/

I'm unable to attach it here, so I added the link.

What are Transition metals

adikasen — 2017-04-23 09:33:07 UTC

•The transition elements are the elements that make up Groups 3 through 12 of the periodic table. These elements are all metals. Like most metals they are lustrous or shiny in appearance and malleable. ( can be mould into shapes without breaking )

Read more: http://www.scienceclarified.com/everyday/Real-Life-Chemistry-Vol-1/Transition-Metals-Real-life-applications.html#ixzz4esAa4xgL

Where can it be found in the periodic table?
http://www.chem4kids.com/files/elem_transmetal.html

Some examples of transition elements and their common uses/relevance to everday life :
- TITANIUM : Aircraft Engines
https://tmstitanium.com/titanium-and-the-aerospace-industry/
- IRON : Iron Bridge
http://www.alamy.com/stock-photo-the-world-s-first-bridge-made-entirely-from-iron-spans-the-river-severn-25314185.html
- NICKEL : Coins
https://www.reference.com/science/made-out-nickel-207018c8f54a25a4
- ZINC : Used in batteries
https://simple.wikipedia.org/wiki/Zinc

Common properties of transition metals

they form coloured compounds
they are good conductors of heat and electricity
they can be hammered or bent into shape easily
they are less reactive than alkali metals such as sodium
they have high melting points - but mercury is a liquid at room temperature
they are usually hard and tough
they have high densities

http://www.bbc.co.uk/schools/gcsebitesize/science/edexcel_pre_2011/patterns/transitionmetalsrev1.shtml

Interesting Facts :
1) The only elements that can produce a magnetic field are Cobalt, Nickel and Iron
2) Of the 38 transitional metals in the periodic table, Australian mines currently produce 10 of them
3) Transition metals are found everywhere on Earth in various amounts. Most are not found in a pure substance, but rather in compounds buried in the Earth’s crust. This means that we must extract the metal from the compound in one of two ways. One process is pyrometallurgical which is when you use extremely high temperatures. The other is hydrometallurgical if you used aqueous solution. ( http://www.chem.uwec.edu/chem115_f02/batesdj/paper.html )

http://www.miningoilgasjobs.com.au/mining/all-you-need-to-know-about-the-mining---metals-sec/quick-facts-about-transition-metals.aspx

How is it relevant to the content of our module?
Towards the end of this semester we will be learning about transition metals so it is good for us to have general idea about what it is before we formally start learning it.

Purple region : Transition elements

Why Do Onions Make You Cry?

2017-04-23 09:37:06 UTC

When you cut an onion, you break cells, releasing their contents. Amino acid sulfoxides form sulfenic acids. Enzymes that were kept separate now are free to react with the sulfenic acids to produce propanethiol S-oxide(C₃H₆OS), a volatile sulfur compound that wafts upward toward your eyes.
This gas reacts with the moisture in your eyes to form sulfuric acid(H₂SO4)
Sulfuric acid burns and stings the eye, stimulating your eyes to release more tears as it helps to wash the irritants away.
This will make you look as if you're crying.

How is this relevant to the content of the module?
This topic is related to chemical reaction of acids and bases . We will be learning on how certain things occur due to a chemical reaction. In this case, how we start to tear due to reaction of acids.

link: https://www.thoughtco.com/why-do-onions-make-you-cry-604309
for further reading:
http://recipes.howstuffworks.com/question5391.htm

propanethiol S-oxide(C3H6OS)

2017-04-23 10:07:32 UTC

hafizin55 — 2017-04-23 10:43:59 UTC

How does a glow stick work scientifically?

beavantang — 2017-04-23 10:46:21 UTC

•Just like many other living things that glow such as fireflies ,fungi ,earthworms and even in the oceans where fishes living at great depths .They have glowing organs containing (chemiluminescence which is an essential ingredient for the glow stick to glow)enabling them to emit light/glow.
•A glowstick consists of a plastic tube filled with hydrogen peroxide( H2O2). There is a small glass tube inside that is filled with phenyl oxalate esters(2,4,6-trichlorophenyl)oxalate (TCPO). When you bend the glow stick, the little tube breaks and the chemicals begin to mix. The result is a glow.

•Reaction type:Glow sticks involve a Redox reaction.
•Word Equation:Hydrogen peroxide + Cyalume [also known as bis(2,4,6-trichlorophenyl)oxalate] + dye ------>>>> trichlorophenol + carbon dioxide + excited dye.

•Chemical Equation:H2O2(aq) + C14H10O4(aq) + dye -> C6H2Cl3OH + 2CO2 + excited dye
Reduction: O is reduced as oxidation state decrease from -1 in H2O2 to -2 in CO2.
Oxidation: CL is oxidised as oxidation state increase from -1/2 in Cyalume to +23/3 in trichlorophenol .

•This is relavant to the topic Redox reaction as it is a chemical reaction in which the oxidation states of atoms are changed. It involves both a reduction process and oxidation process which are the two key concepts involved with electron transfer processes ,which is similar to the reaction occurring in the glowstick.
•For further reading: http://dpglowstick.weebly.com/chemistry-stuff.html
https://www.thoughtco.com/how-do-lightsticks-work-607878
https://en.m.wikipedia.org/wiki/Glow_stick
https://www.thefactsite.com/2009/01/brighten-up-your-day-with-glow-sticks.html

What kind of reaction is Respiration under?

2017-04-23 11:24:30 UTC

The energy that our body needs comes from the food that we eat. The Mitochondria in our cells is where energy is harvested from food molecules. Respiration(aerobic) takes place in the mitochondria as follows :

Glucose + Oxygen ----> Carbon dioxide + Water + Energy(large amount)

Hence, heat energy is produced during respiration. This is why during exercise, we feel the heat that is coming out from our body it is respiration that provides us with sufficient energy to allow us to keep exercising.

Therefore, Respiration is an exothermic reaction. An exothermic reaction is one in which heat energy is given out, causing a rise in temperature of the surroundings.

eskailashwaran — 2017-04-23 12:01:04 UTC

WHAT IS ACTIVATED CARBON?

2017-04-23 12:34:11 UTC

What is it?

Activated carbon is carbon that is processed to have many small pores that increase the surface area for more absorption or chemical reaction.

Properties of Carbon:
Atomic number : 6
Melting point: 3652 °C
Boiling point: 4827 °C
Others: Black,odourless, tasteless & nontoxic

Common Usage :

1.  Rid Your Body of Toxins in Emergency Situations! ∑(ﾟДﾟ)

Since our body is unable to digest activated charcoal, toxic substances that are bind and attached to the surface of the charcoal will not be absorbed into the bloodstream and eventually be excreted from our body.

Short Video for your Reference: https://youtu.be/fnt0Ub_tem8

2.Manufacturing Beauty Products !! (⁎⁍̴̛ᴗ⁍̴̛⁎)

Nowadays activated carbon is being made into toothpaste, masks and other beauty products. As activated charcoal removes toxins, it helps to reduce acne and other skin impurities. It also works well on teeth whitening!!!

Further Reading :
https://draxe.com/activated-charcoal-uses/
This is simply relevant to the chapter of Periodic Table! Which we learn about the properties and different usage of the elements .

hafizin55 — 2017-04-23 13:18:51 UTC

hafizin55 — 2017-04-23 13:18:52 UTC

hafizin55 — 2017-04-23 13:18:53 UTC

hafizin55 — 2017-04-23 13:18:56 UTC

hafizin55 — 2017-04-23 13:19:42 UTC

How does antacids work to relieve acidity and heart burns

s10180225 — 2017-04-24 10:39:43 UTC

Antacids are a group (class) of medicines which help to neutralise the acid content of your stomach. Antacids include aluminium hydroxide, magnesium carbonate and magnesium trisilicate. These come in various brand names and are available as tablets and liquids.

Some antacids are combined with another medicine called simeticone which helps to reduce wind (flatulence).

Another group of medicines called alginates are found in some brands of antacid medication. Alginates are added to help protect the lining of the gullet (oesophagus) from stomach acid. Alginates include sodium alginate and alginic acid. They are present in antacid medications with various brand names.

For further reading:
https://patient.info/health/antacids

This is relevant to the topic of acids and bases as it is a neutralisation reaction between acid and bases.

How do batteries work(Alkaline)

eskailashwaran — 2017-04-24 11:50:22 UTC

In a battery there is two electrodes which cathode(positive terminal) and anode(negative terminal). In between the electrodes there is electrolyte, a ionic liquid which conducts electricity.
In context of alkaline battery, the anode is zinc, cathode is manganese dioxide and electrolyte is potassium hydroxide. Reactions will be taking place at both electrodes. It is redox reaction too.
At positive terminal:
2MnO_2(s) + H₂O_(l) + 2e⁻ → Mn₂O_3(s) + 2OH⁻_(aq).At negative terminal:
Zn_(s) + 2OH⁻_(aq) → ZnO_(s) + H₂O_(l) + 2e⁻ Overall reaction:
Zn_(s) + 2MnO_2(s) ⇌ ZnO_(s) + Mn₂O_3(s) All this reactions will make the electrons to move around the circuit. Moreover, difference in electronegativity between the materials of electrodes plays a part in making the electrons to move around the circuit.
For further reading:http://www.explainthatstuff.com/batteries.html
https://www.electrical4u.com/alkaline-batteries/

This is relevant to the topic chemical bonding as the example above shows the application of electronegativity which is a measure of the tendency of an atom to attract a bonding pair of electrons.This also serves as a example for redox reactions.

What is acid rain?

mahirahwaled — 2017-04-24 13:50:48 UTC

Normal rain has a slightly acidic pH of 5. However, acid rain has an even lower pH of 4 Acid rain is formed when compounds like sulfur dioxide and oxides of nitrogen dissolve in rainwater, causing the rainwater to turn acidic. Acid rain is dangerous as it damages agriculture crops, kills aquatic life and corrodes buildings. Compounds of sulfur dioxide and oxides of nitrogen are found in the atmosphere due to human activities such as the burning of fossil fuels. Therefore, in order to stop acid rain, we must learn to conserve energy which will help in reducing the emission of such compounds in the atmosphere.

For further reading : http://www.nationalgeographic.com/environment/global-warming/acid-rain/

This is relevant as in inorganic chemistry, we will learn about the harmful effects of acid in “Acids and Bases”. Furthermore, we will learn how we can neutralise acids using a base in “Chemical reactions”.

What does hydrochloric acid (HCl) in the stomach do?

nicchan — 2017-04-25 12:19:41 UTC

Functions of hydrochloric acid in stomach:

Stomach lining cells produce a substance known as pepsinogen. HCl in the stomach converts this pepsinogen into the enzyme
pepsin, allowing us to digest the protein in our food.
Acidic environment caused by HCl kills harmful bacteria that enters the stomach, hence protecting stomach and small intestine from harm.
HCl aids in the absorption of minerals such as iron and vitamin C.

For further reading: https://owlcation.com/stem/Hydrochloric-Acid-in-the-Stomach-and-Digestive-Problems

This is relevant to the chapter “Acids and Bases”. In the chapter, we will get to study the various types of acids. In this case, we get to learn about some of the functions of hydrochloric acid and how it is used in the human body.

How is radiation used in medicine?

shanyareddyy — 2017-04-26 09:44:26 UTC

Radiology is a branch of medicine concerned with the use of radioactive material in the diagnosis and treatment of diseases.

X-rays are the most well known form of radiology, and they are electromagnetic radiation (photons) that can be emitted from radionuclides or from certain types of devices. An X-ray is able to pass through many materials opaque to light and penetrate the body, being absorbed to different degrees by different materials.

X-rays are thus used to produce photographic or digital images of the internal composition of the body, such as the chest, ribs, lungs and heart, and help identify broken bones and diagnose or locate tumors.

Computerized tomography, or CT scans, use x-rays and computer processing to generate two-dimensional pictures of the inside of the body. This allows doctors to see through an entire organ to identify causes of pain or diagnose tumors without cutting.

For further reading: http://www.radiationanswers.org/radiation-sources-uses/medical-uses/radiology.html

This is relevant to the content of the module as radiation is a part of nuclear chemistry, and we can learn how nuclear chemistry is applied in the medical industry through radiation.

2017-04-26 11:30:27 UTC

2017-04-26 11:30:31 UTC

Catalytic converter in vehicles.

2017-04-26 11:36:43 UTC

Catalytic converters in simple term is like breaking up harmful molecules of gases and turning them to less harmful gases when leaving the engine of cars and before the gas gets released into the air. So, they are basically important in reducing the amount of harmful pollutants that gets exposed to our atmosphere.
Catalytic converters works in a way that gas will flow pass a dense honeycomb structure made of ceramic and is coated with catalyst. The catalyst speeds up chemical reaction which speeds up the conversion of harmful gases into less harmful gases. The catalyst used are Platinum, Rhodium and Palladium, in which are Platinum group metals(transition metals). One catalyst will convert
2NO → N₂ + O₂
(Reduction of Nitrogen)
Another catalyst converts
2CO + O₂ → 2CO₂
(Oxidation of Carbon)
Lastly converts, (hydrocarbons)
C_xH_y + O₂ → CO₂ + H₂O
(Oxidation of hydrocarbons)

Catalytic converter may not be what we will learn in the upcoming topics, but the relevant topics includes transition metals and redox reaction.
Further reading & reference
>http://www.chemistry.wustl.edu/~edudev/LabTutorials/CourseTutorials/Tutorials/AirQuality/CatalyticConverter.htm
>http://www.explainthatstuff.com/catalyticconverters.html

Is it possible to turn lead to gold?

legreen321 — 2017-04-26 13:26:23 UTC

Since the 300 BC right till the advent of modern chemistry and physics, alchemy had been practiced widely throughout it's land of origin in Egypt, Asia and most commonly known in Europe. Alchemists had sought after the Philosopher's Stone, a substance said to help turn lead into gold.

Theoretically, turning lead to gold is entirely possible. After all, all substances are just made up of a different numbers of the same 3 things-protons, neutrons and electrons.

With the aid of technology and better understandings of science, transmutation is made possible today and in 1980, Glenn Seaborg had successfully transmuted bismuth into gold. However, due to the large amounts of energy needed to extract the protons, the gold obtained is lower in value than compared to the bismuth used.

This relates to our module as atoms play a vital role in chemistry and chemical reactions. After all, atoms make up everything in the world. It is also truly fascinating to think that everything we see and know in this world is made simply of different combinations and arrangements of neutrons, protons and electrons.

Further reading:

legreen321 — 2017-04-26 13:57:33 UTC

The Alchemist Discovering Phosphorus by Joseph Wright of Derby, 1771

hafizin55 — 2017-04-27 03:08:50 UTC