Chemical reactions: Rusty cast iron cookware

rustNobody likes rust. It ruins metal. It looks bad. It takes no prisoners. What is rust?

Corrosion is when the metal’s metallic properties are lost due to oxidation. When iron corrodes, it causes rust.

Rust is the red flakes you see on the iron. Those flakes can flake off and eventually the iron metal will develop a hole.

The chemical composition of rust is Fe2O3.nH2O. It occurs when Fe (iron) contacts 02 (oxygen) and h20 (water).

For example, this occurs with cars, which are exposed to the elements, and cast iron cookware.

Cast iron cookware can rust if not seasoned and taken care of properly. It is different than stainless steel or nonstick pans.

Let’s take a look at how to do that to avoid Fe2O3.nH2O and a way to restore or repair that dutch oven or skillet.

Rusted to pieces?

Many people will recondition a cast iron skillet that has been neglected and has rust. Below is a 19 minute YouTube video from a guy who explained how to restore cast iron skillets.

It is pretty amazing how he uses the self-cleaning oven to get the gunk off a skillet.

Cleaning, seasoning new pan

When you get a new cast iron pan or dutch oven that is not seasoned, you want to wash it with soap and water. (Some manufacturers all ready season dutch ovens and skillets this site notes.)

A Brillo pad with soap works well. Once the skillet has been seasoned, you won’t use soap again.

It needs to be dried completely before seasoning. To start seasoning, use a solid shortening and wipe the shortening over the inside and the outside of the skillet.

After adding the shortening, place the pans upside down on an aluminum covered cookie sheet and let them heat in the oven for an hour or so at 350 degrees F. Turn the oven off and leave the pan in the oven, where it can cool.

Now that the pan is well-seasoned, you don’t want to use soap when cleaning it from now on. You should use hot water. After washing, set the pan on the stove-top to air dry completely before putting away. When putting away, don’t put a lid on the pan because it can trap moisture, which will cause your pan to rust.

Before cooking that lovely T-bone in your pan, consider cooking a few high-fat meats first. High fat meats like bacon will continue to improve the seasoning of your pan.

Seasoning will keep the pan in good shape. Cast iron will last a lifetime. Although there are plenty of companies that make new cast iron cookware according to this site, there are plenty of forums and groups of people who seek out older cast iron skillet brands that are made in the USA.

It is tough to say which is better getting a inexpensive, second-hand skillet or spending a lot of money on a new one. Both have their merits and detractors. Either way, keep the rust at bay.

Chemistry used in an EMT’s job

emt to rn
Photo: Billie Ward via Flickr, CC BY 2.0

Emergency Medical Technicians, or EMTs, are the first medical responders to various crisis situations. These are but a few of the emergency situations that EMTs are called to respond to – wounds and injuries of various causes, poisoning, childbirth, heart attacks, burns, animal bites and attacks, suicides and many more.

An EMT has at least 120 hours of training and a certification. Do EMTs need chemistry to become effective professionals in their field? Of course, they need Chemistry among the many things they need to learn. Hereunder are some of the reasons for emphasizing chemistry in the EMT training course.

Foremost in the job of an EMT is the ability to make quick but judicious assessments in crisis situations. A person could be injured or sick and needs medical attention. Medicines and first-aid procedures may need to be administered in transit to save a life. It is one of the EMT’s responsibilities to stabilize the patient, to assess which patient needs to be prioritized in multiple-injury situations, and to ensure that they are secure while waiting for the medical team or while being transported to medical facilities. Chemistry is a broad-range subject and includes temperature, chemical composition of medicines, components of everyday things (soap, toothpaste, toilet cleaners, plastic household items, burnt plastics, food preservatives and hair color), the air we breathe, and the water we drink. Thus, an EMT interacts with chemicals and chemistry every day, as most people do. Awareness on this becomes important when there is a need to respond to persons who have been exposed or harmed by these substances. Fumes from burnt plastic can be instantly dangerous for some people. Clear liquid for cleaning metals that look like water can be swallowed by small children. EMTs respond to these situations and they must be several steps ahead.

There are situations or accidents where EMTs find people exposed to certain chemicals. Their knowledge on the toxicity of certain chemicals may spell life and death for the affected person. More often than not, they would need to do something immediately to contain or control toxicity. Chemical residues in accident sites can be harmful, and they may need to practice protection and precaution. There are water-reactive chemicals and it would definitely be life-saving for EMTs to know which chemical can be neutralized or flushed with water and which ones are dangerous when wet.

When they are part of the response team for fire-fighting or disposing hazardous materials, knowledge in chemistry is something they must be solid on. Symbols might indicate that a particular chamber has gas that’s flammable, poses a health hazard, can undergo spontaneous combustion at certain temperatures, or may explode in reaction to certain conditions. Many situations expose them to acids and bases, and chemical burns are always possible dangers. EMTs are everywhere during emergency situations, and their knowledge on basic chemistry can save people’s lives, if not their own.

EMTs administer rehydration treatment for hypoglycemic emergencies, oxygen supplementation for stroke patients, and other procedures. Deeper understanding of the chemistry behind these protocols will be both beneficial and ethical to patients, especially with issues that too much oxygen can’t be that good after all.

No doubt, an EMT has a lot to learn, even beyond the minimum 12-hour required for entry-level EMTs, basic chemistry, and other job-ready skills. Emergency-responders are often first on the scene – assessing signs and symptoms, taking blood pressure, using a stethoscope for auscultations, giving medication and first aid, recording medical history and events leading to the emergency, transporting patients, and ensuring that the affected persons get the medical attention they need in the fastest and safest manner possible. These responsibilities and dedication to the job motivate EMTs to advance to the next level in three or four higher levels in the EMT profession. Others, too, are inspired to explore other medical-related fields of profession, such as EMT to RN or EMT to other healthcare careers, to pursue even bigger roles in medical and emergency response care. Since EMTs work closely with nurses in handling patients, the EMT-to-RN route is a usual path followed for career advancement. EMTs rarely stay in their jobs for good because the challenges they encounter on a daily basis stimulate them to grow and be more involved with greater responsibilities.

Chemistry in the Kitchen

Credit: mmu-engage, CC-BY-2.0
Credit: mmu-engage, CC-BY-2.0

Kitchens are chemistry laboratories in disguise; but did you know that? When you prepare food, you use ingredients such as sodium bicarbonate, fructose, sodium chloride, lactic acid, sulphur dioxide, and other chemical names, but which we know ordinarily in their kitchen names like baking soda, sugar, or salt. Unknowingly, chemical processes take place in your little chemistry lab, such as oxidation as a reaction of polyphenol oxidase in apples and most fruits with oxygen in the air, or freeing of carcinogenic perfluorooctanoic acid (PFOA) fumes to the environment when you cook on your Teflon-coated non-stick pans.

There are a lot of items in the kitchen which you know by their common names or perhaps brand names, but not in their chemical names or composition. Remember a time when you’re cooking and there’s an ingredient you forgot to include during your weekend shopping? It’s very likely that there’s an item around that could substitute for that lacking ingredient, but what? It would have been a handy thing if you knew kitchen items by their chemical composition or behaviour.
Here’s Kitchen Chemistry 101 – familiarizing with ingredients chemically.

Ammonium bicarbonate

For every ¾ teaspoon of ammonium bicarbonate, you may substitute 1 teaspoon of baking soda (or sodium bicarbonate).

Baking powder

You’re out of baking powder, but you need it very badly or the cake you’re baking will fall flat. Check the pantry if you have baking soda, cornstarch and cream of tartar. Lucky you, we have the ratio for that. For every teaspoon of single-acting baking powder that your recipe requires, use ¼ teaspoon of baking soda, ¼ teaspoon of cornstarch, and ½ teaspoon of cream of tartar. Both baking soda and baking powder result to production of carbon dioxide bubbles and “rising” in the cake. Baking soda must be mixed with an acidic ingredient such as yogurt and cream of tartar. Baking powder, on the other hand, is a ready-mixture of sodium bicarbonate, cream of tartar and starch.

Use the same mixture if your recipe calls for double-acting baking powder, except that you should measure 1 teaspoon of this mixture for every cup of flour used in the recipe.

Baking soda

Most households seem to never get enough of this versatile item simply because they’re multipurpose – they bleach teeth, whiten the fridge, clean the bathroom tiles, make the loaf crusty and the cookie well-browned, help in the kids’ science projects, plus a host of other home uses. To substitute in baking, you may substitute 2 teaspoons of double-acting baking powder per ½ teaspoon baking soda required. A teaspoon of potassium bicarbonate is also equivalent to a teaspoon of baking soda. Unfortunately, these substitution tips won’t work in your son’s science volcano project.


You can still cook your buttermilk waffles even without buttermilk if you have 1 tablespoon lemon juice or vinegar and milk. One cup of this mixture is equivalent to 1 cup of buttermilk – just allow it to stand for 10 minutes before you pour it into your recipe.

Cake flour

What’s a cake without cake flour? Well, as long as you have all-purpose flour and cornstarch, the cake shop will continue to be in business. One cup (130 grams) of cake flour can be substituted with ¾ cup (105 grams) of all-purpose flour and 2 tablespoons (30 grams) of cornstarch. But what happens if you only have all-purpose flour? Stress not. For every 1/3 cup of cake flour needed, use 1/3 cup all-purpose flour less ½ teaspoon.


You may use 15 grams of unsweetened chocolate and 1 tablespoon sugar for every 30 grams of bittersweet chocolate required. On the other hand, if it’s unsweetened chocolate you need but you don’t have it at the time you’re baking, you may mix together 20 grams of natural cocoa powder with 14 grams of vegetable oil for 30 grams of unsweetened chocolate. Instead of vegetable oil, you may also use unsalted butter or shortening in the same proportion.

Cocoa powder

For a recipe that requires cocoa powder, you may replace it with unsweetened chocolate and baking soda. Use the ratio of 30 grams unsweetened chocolate and 1/8 teaspoon baking soda to 20 grams of cocoa powder. Since chocolate is already high in fat, decrease the butter or shortening in the recipe by 1 tablespoon for every 30 grams of chocolate added.


For every ¼ cup of black coffee called for in the recipe, you may substitute 2 tablespoons instant coffee dissolved in 3 tablespoons of hot water.

Corn syrup

There are recipes, such as caramels, that require dark corn syrup. If what you have in stock is light corn syrup, you may use ¾ cup of it mixed with ¼ cup light molasses to take the place of 1 cup dark corn syrup.

One cup white sugar in ¼ cup liquid (water or the liquid used in your recipe) may replace 1 cup of light corn syrup.


Cornstarch is the preferred ingredient for thickening sauces, possibly because it thickens quickly and kitchen cooks have grown in the kitchen using them for the purpose. However, all-purpose flours give equally satisfying results, just double the measurement.

Cream of tartar

You’d think that you substitute another powder for cream of tartar, but nope! Use ½ teaspoon of lemon juice for 1/2 teaspoon of cream of tartar. If there’s not a piece of lemon anywhere near you, use white vinegar instead.

Cream half-and-half

This is simply 2 tablespoons of melted unsalted butter added to 7/8 cup of whole milk. Presto! You have a cup of cream half-and-half.


Concoct your own heavy cream by mixing 2/3 cup of whole milk and 1/3 cup of melted unsalted butter. That’s equivalent to 1 cup of heavy cream.

For sour cream, you may use plain yogurt, cup for cup. If there’s neither yogurt or sour cream and your cheese cake can’t wait, mix this 1 tablespoon lemon juice and whole milk to make 1 cup. That should be equivalent to 1 cup of sour cream.


You can’t be out of flour, can you? But you can be out of wheat flour. Now, if you have flour and wheat germ in the cupboard, there’s no reason anybody is going to miss her wheat loaf in the morning. Mix 7/8 cup of all-purpose flour and 2 tablespoons of wheat germ to replace 1 cup of whole wheat in the bread recipe.
Marshmallow cream

Unless you’re a fan of homemade Whoopie Pies, marshmallow cream is not a staple item on the shopping list. However, if you ever need it in any of your dishes, you can use a cup of marshmallows for 2.5-oz cream.


Here’s a good substitute for condensed milk. Mix 1 cup of non-fat powdered milk, 2/3 cup granulated sugar, 3 tablespoons unsalted butter, and ½ cup boiling water. The blended mixture is equivalent to 1 cup of the real thing.

For 1 cup whole milk, combine 1 cup skimmed milk and 2 tablespoons margarine or unsalted butter.

Evaporated milk and half-and-half can take each other’s place in most recipes.

Substituting does not only come handy when you’re short of an ingredient. You may also resort to it when a member of the family reacts to, or has a health condition that does not sit well with a particular ingredient. This additional knowledge goes a long way. It does not need hard-core chemistry, and it does save you from unnecessary errands to the grocer or an allergic reaction.

Household chemicals which don’t go together

Credit: David Carroll
Credit: David Carroll

The home is a family’s symbolic shelter that keeps every member safe from elements and intruders. Yet, it may also house innocent-looking household chemicals that may not be so safe, after all.

These things don’t mix

1. Different brands

As a general rule, don’t mix different brands of the same type of products. Not because they are competing products, but because you don’t exactly know their chemical composition or how they will react with each other. A toilet cleaner, for instance, is manufactured from strong chemicals. Mixing it with another chemically-potent cleaner will most likely produce toxic fumes, dangerous chemical reaction, or an ineffective product.

2. Bleach and other products

Bleach is generally a chlorine compound. Chlorine bleach, for example, may have a chemical name of sodium hypochlorite. If mixed with toilet cleaning agents, ammonia, vinegar or other acidic products, hazardous vapors (such as chloramine) are released. Rubbing alcohol (ethanol or isopropyl) plus bleach equals chloroform, chloroacetone and hydrochloric acid.

3. Acidic and alkaline products

The reaction between acidic (such as hydrochloric acid and oxalic acid) and alkaline products (such as sodium hydroxide for drain cleaning) can be quite violent and may cause burns or blisters.

4. Disinfectants and detergents

Detergents contain quaternary ammonium compounds which may reduce the effectiveness of disinfectants.

5. Hydrogen peroxide and vinegar

Hydrogen peroxide is an antiseptic that has many uses (it often acts as hair bleach and teeth whitener). When mixed with vinegar, though, it produces parecetic acid which is a corrosive and irritating acid. In high concentrations, it may even cause permanent scars to the skin and damage the eyes.

These things are mild poisons

If you have curious tykes around the house, you can’t have too many poisons (mild or otherwise) lying around. Run the list below to see if you have these items at home.

1. Antifreeze (ethylene glycol)

It tastes sweet and is common in households – bad combination. That it’s a mild poison isn’t reassuring at all. It usually comes labelled with a warning, but kids and pets are not known for reading labels before they nibble at anything that fancies them.

2. Rat poisons (containing strychnine)

Water sometimes gets contaminated with this toxic chemical. Aside from that, strychnine may also be contained in commercial rat poisoning products and other pesticides. It results to convulsions and death by asphyxia. Those exposed to the poison have a chance of surviving, if that’s any consolation.

3. Nicotine patches and vaporizer (Nicotine)

They say that smoking is a slow and enjoyable form of suicide. That’s because nicotine kills, albeit slowly. Quitting smoking via alternatives like nicotine patches or nicotine vaporizers are common solutions. If you’re not careful, however, death may come quicker. A dose of 50mg could be quite lethal for a 65-kg adult, and the chemical is accessible in many households either as nicotine patches or nicotine liquid (used for vaporizing).

4. Formaldehyde in your nail polish, car exhaust and paint

It could even be on your carpet. Formaldehyde can cause allergies, headaches, and even cancer. It’s toxic to animals, too.

5. Fluorine

Fluorine is toxic to humans. It has damaging effects to the brain and the nervous system. What’s worse – it’s everywhere and in almost everything. Fluorine is in your toothpaste, water, reconstituted fruit juices, canned food, non-stick pans, and drugs.

If you’re getting paranoid, then it’s not baseless. At any rate, get hold of yourself. It might be impossible to totally avoid these things. The thing is, you know what you feed yourself and your family.
Read labels, listen to issues, and learn the chemistry of ordinary things.

Chemistry is not restricted in school; it’s everyday life. Knowing the chemical breakdown of things will help you make decisions on what items to remove from your home, and what things simply don’t mix.

Basic Chemistry Questions: Let’s Get the Brain Stewing

Chemistry nomenclature questions

Horia Varlan
Horia Varlan

Here are a series of chemistry nomenclature questions, along with questions about pressures, gas laws, and a little history about Charles, Dalton, Graham, and Boyle. Answers are at the bottom.

1. What are positive ions called?
2. What are negative ions called?
3. What are two types of bonds that hold compounds together?
4. Compounds that contain a metal will create what type of bond?
5. A ___________ bond uses a prefix method for naming compounds.
6. What type of bonds hold polyatomic ions together?
7. Metals bonded with polyatomic ions will create a compounds with which type of bond?
8. What type of bond can create a single molecule?
9. Why can oxide of iron have the formula Fe2O3 and FeO?

10. What is the proper name for each formula below:

  • AgOH
  • SiBR4
  • N2O4
  • Fe(NO3)2
  • CO
  • KH2PO4
  • PbF2
  • Na2CrO4
  • PCI5
  • As2S3
  • NH4C2H3O2
  • Cu2SO4
  • Li2O
  • SnCO3
  • P4O10

12. What is the proper formula for each compound below:

  • Aluminum chloride
  • Calcium bromide
  • Dinitrogen monoxide
  • Iron (III) oxide
  • Sodium bicarbonate
  • Lead (IV) nitrate
  • Mercuric sulfate
  • Carbon tetrachloride
  • Copper (I) phosphate
  • Calcium acetate
  • Iodine heptafluoride
  • Magnesium hydroxide
  • Ammonium sulfide
  • Carbon dioxide

True or False questions

13. Charles’ Law can be represented as PV=K
14. The value for pressure at standard conditions is 101.3kPa.
15. A temperature of -23K is equivalent to 250 degrees Celsius
16. Boyle’s law is an example of a direct proportion.
17. Doubling the volume of a gas at a constant temperature would change the pressure to 1/4 of the original pressure.
18. Boyle, Charles, and Dalton all have ties to the kinetic theory of gases.
19. The equation R=PV/nT, where R=8.3 kPa–L/mole K, is a representation of the ideal gas law.
20. Four moles of carbon dioxide gas and four moles of oxygen gas have the same mass.
21. The density of bromine gas at STP is 7.13 g/ml.
22. The volume of a 150 g sample of sulfur dioxide with a pressure of 745 torr and a temperature of 15 degrees Celsius is 5L.
23. Charles’ law represents an example of an inverse proportion.
24. Dalton is attributed to the law of partial pressures.
25. Absolute zero is equivalent to -273K.
26. When you solve a problem using the combined gas law, the pressure must be held constant.
27. Temperature determines the average kinetic energy of the molecules of a gas.
28. Standard volume of a mole of any gas is 22.4L.
29. An increase in the temperature of a gas will cause an increase in the density of the gas.
30. Graham’s law is about the diffusion rate of a gas.
31. The pressure on a container wall increases as the number of collisions on the walls of the container increases.


1. cations
2. anions
3. ionic and covalent
4. ionic
5. covalent
6. covalent bonds
7. ionic bonds
8. covalent bonds
9. Iron is a transition metal that can form cations with a +2 or +3 charge. Because the total ionic charge has to equal zero, iron’s charge will vary based on what element (and how many atoms of that element) that it’s attached to.
– silver hydroxide
– silicon tetrabromide
– dinitrogen tetraoxide
– iron (II) nitrate
– carbon monoxide
– potassium dihydrogen phosphate
– lead (II) flouride
– sodium chromate
– phosphorus pentaflouride
– diarsenic trisulfide
– ammonium acetate
– copper sulfate
– lithium oxide
– tin (II) carbonate
– tetraphosphorus decaoxide

12. False
13. True
14. False
15. False
16. False
17. True
18. True
19. False
20. False
21. False
22. False
23. True
24. False
25. False
26. True
27. True
28. True
29. True
30. True
31. True