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What is Molarity? Molarity is by far the most common way to measure a solution concentration. So whenever you see the word concentration in a problem always immediately think molarity. The definition of molarity is moles of solute per liters of solution. I have written the equation below. Molarity = Moles of Solute Liters of Solution In order to think of it in a more simplistic way and help with problem solving I have simplified the formula…

What sections should I know before attempting to learn this section? —> Covalent, Ionic, and Metallic Bonds —> Forming Ionic Compounds —> Breaking Apart Ionic Compounds —> Introduction to Polyatomic Ions Part 1   How do you name ionic compounds with polyatomic ions? The last hurdle to tackle in ionic compounds has to do with polyatomic ions. These examples and practice problems work in the same ways as…

  One immediate division you might have seen on the periodic table is that the elements and their corresponding boxes are organized into vertical (up and down) columns and horizontal (left to right) rows. This link shows a periodic table with the columns (groups) and rows (periods) labeled. You should open that link up and keep it with you to compare with the explanations and examples in this section. In chemistry , we call the vertical…

What are phase diagrams? Phase diagrams are a way to display how the conditions of pressure and temperature act separately or together to change or create the different phases of solid, liquid, and gas. Now that we know some of the terminology used with phase diagrams from the last section we can move on to displaying and analyzing them. All phase diagrams display the same information but depending on which chemical you are analyzing in your…

How do different states of matter form? Why do different states of matter form? VIDEO explanation of the formation of states of matter. The different states of matter form because of the specific conditions of chemicals in that part of the universe. Where we most commonly interact with matter, our planet Earth, the different states form mainly because of the amount of gravity that the earth generates. This gravity is sorting the chemicals on…

How do you use the reaction quotient? Now that we know how to calculate the reaction quotient (Q) we can talk about what it means and how to use it. Most books explain it in terms of comparing the reaction quotient (Q) to the equilibrium constant (K).   These are the classic phrases that people put in books:   If Q is LARGER than K then the reaction will proceed to the LEFT. If Q is SMALLER than K then the reaction will proceed to the…

What are Partial Pressures? The concept behind partial pressures is quite simple, but many books and example questions make the thinking behind them overly complicated. Partial pressures is all about adding up the pressures of each gas separately in a container to get the overall (total) gas pressure inside that container. For example, our atmosphere is a container. 99% of our atmosphere is made up for Nitrogen (N2), Oxygen (O2), and Carbon…

What is the relationship between different equilibrium constants? VIDEO Explanation and Example Problems for the Relationship Between Equilibrium Constants. Within the same chemical equation, questions can be asked about what happens to the equilibrium constant if we change something to that equation. There are two classic examples that pretty well illustrate the point of how it works. The first is what happens when you multiply the chemical…

  Now we explore the next step in our conversion map. This step will help us explain the definition of a mole. A mole is something that is hard to understand at first. Quite simply , a mole is just a number of objects in this case atoms or molecules. Therefore , a mole is an amount of something. The best analogy to a mole is a dozen. A dozen is an amount of something, specifically 12 of them. The only difference between a dozen and a mole…

How do you do conversions between pressure units? Fundamentally, the pressure of a gas is how many times and with how much force are the molecules of air striking the container. It is like a massage. The person giving you a massage can strike your skin in many different ways. They can strike hard and often which would be high pressure or they can strike soft and infrequent which would be low pressure. The same is true with the molecules of air…

HOW DO WE CALCULATE Δ G (First Way)? There are two different ways to calculate Δ G (Delta G). The first is look up the Δ G values on a Gibbs Free Energy Table (DELTA G) and then take the Δ G of the products minus the Δ G of the reactants. This is the same technique you used in the how to calculate Δ H section only you are going to use values found in a slightly different table (Gibbs Free Energy / Spontaneity Table) . The equation for the Δ G…

  How do we calculate the energy required to move an electron between energy levels? The answer is the Rydberg equation. Note this Rydberg equation can only be used for hydrogen energy levels or shells . It is shown below. The equations are written two different ways. Both of the equations are the same but the second one is organized better for future demonstrated examples.   Δ E = R H ((1/n I 2 ) – (1/n f 2 ))   Δ E = 1 –…

What sections should I know before attempting to learn this section? —> Covalent, Ionic, and Metallic Bonds —> Forming Ionic Compounds —> Breaking Apart Ionic Compounds   How do you name ionic compounds with transition metals? From this point, we also have to tackle ionic compounds that are made up of what are called transition metals. These metals are roughly in the center of the periodic table and do not always…

  What is matter and what are the elements? Matter consists of all the things we interact with physically in our daily lives. Matter is anything that we can physically touch or has a mass. So matter is everywhere. It is in the computer you are reading, the chair you may be sitting in, and even the air around you is made up of matter. The only thing we commonly think of that does not have matter is outer space. Elements are the individual…

What are chemical equation coefficients? Chemical equations also need to be balanced. The above chemical equations are not balanced. All further chemical equations on this page should be balanced (If they are not practice problems). This means they have to have the same amount of each element on the reactants side as they do on the products side . The trick to balancing is that you cannot change the compounds by changing the subscript. However,…

  What is this lesson about? This lesson is about the units of measurement chemistry uses and how you can use those units to covert between each other. It also includes and introduction to skills in how to solve word problems, which very often contains the units talked about in this lesson. This problem solving work will also continue throughout many of the chapters but it starts here.   Why is it critical to understand? Perhaps the…

How do you learn to find polyatomic ions in compounds? What you want to start doing in this section is getting good at spotting polyatomic ions whenever and wherever you see them. Many of them will be hidden in the chemical formulas you will see in the future of chemistry. The better you become at identifying them, the better you will be at solving future chemistry problems.   Examples: Pick out the POLYATOMIC IONS from the chemical…

What is Fusion? There are two basic ways to go about creating new elements. One is to take lighter elements like Hydrogen and turn them into heavier elements like Carbon and Iron. This lighter to heavier process is called fusion . In fusi on, y ou basically take two lighter elements and smash them together to make heavier elements like taking two pieces of small co okie dough a nd making a bigger cookie. The most common way for fusion to…

  What is the atomic radius? For this section, open up your atomic radius periodic table with this link. The atomic radius means the size of an atom. Since the atom is a circle and the length of a radius of a circle determines its size , this is why they call the size of the atom the atomic radius. T here are two factors that determine the atomic radius. First is the amount of electrons or electron shells it has. The more electrons an…

HOW DO YOU CALCULATE ΔH (DELTA H)? Once you memorized the relationship between the side the energy is on in a chemical equation, the Δ H and endothermic or exothermic, you are probably curious about how Δ H is calculated. It is calculated by the total energy contained in the molecules of products minus the total energy of the molecules in the reactants. Any time you are calculating the Δ of something it is always FINAL – INITIAL. Another way to…

What sections should I know before attempting to learn this section? —> Covalent, Ionic, and Metallic Bonds   How do you use a covalent (molecular) name to create the covalent compound? Now that we have taken the covalent chemical compound and produced the chemical name (as we did in the previous section) we should try the other direction. That is taking the chemical name and producing the chemical compound. Remember to use the…

How can you tell if products or reactants are favored in equilibrium? Sometimes questions are asked about what the equilibrium constant, K, tells you about the equation. The answer that they are looking for is either K tells you that the products are favored or the reactants are favored. If the products are favored then K will be a number larger than 1. Another way to say it is that the numerator will be large or the denominator will be small….

  Proportions or ratios are an important part of math in chemistry. They are normally used when comparing two different elements, compounds, or amounts. Don’t let the two words confuse you. They are actually the same thing. A proportion is a ratio and and ratio is a proportion. I know some math fanatics out there may argue that last statement with me but this a science website so I don’t care. Most importantly, what is a…

What are ICE or RICE tables and how do you use them in equilibrium? EXPLATION VIDEO Solving ICE Tables Demonstrated Example 1 : If the initial concentration of N 2 was 2M, and the initial concentration of H 2 was 7M. What would be the concentration of NH 3 be at equilibrium if the concentration of N 2 at equilibrium is 1.5M? Use the balanced chemical equation below. N 2(g) + 3 H 2(g) <—-> 2 NH 3(g)   First set up the ice table….

What is a spontaneous process or what is spontaneity? Spontaneous has to do with completing a process without any outside help . For purposes of chemistry we will be talking about the chemical reaction (chemical equation) when we talk about the process. So, what is meant by outside help? The best and easiest way to think about outside help, in terms of chemistry, is that outside help is any form of energy put into the process . In other words,…

What is an Equilibrium? This is one of the most confusing concepts and chapters in chemistry. The reason is not many people tend to think of an equilibrium in their lives. An equilibria or an equilibrium is creating a balance. This does not have to be an equal balance. Here is example of a non-chemical equilibrium. You strike a balance in your every day life. The balance is between work, sleep, and school. Not everyone creates a perfectly equal…

  If we look at the periodic table , we notice that there are different individual boxes. Each of these boxes represents a different element and what a single atom of each element consists of. The different elements are represented by one or more letters. These letters are the elemental symbol . For example , the element hydrogen is represented by H and the element Calcium is represented by Ca. If a letter is uppercase that means it is the…

How does Equilibrium relate to acids and bases? Ka and Kb Ka and Kb are the representations of the equilibrium constant for acid or base reactions. Again , there is nothing different in the math or equation set up for Ka or Kb. All equilibrium acid or based chemical equations are set up in one direction like the examples below ; where the acid or base together is shown on the reactants side and the ions of the acid or base is shown on the…

What sections should I know before attempting to learn this section? —> Protons and Electrons   How do I find the neutrons of an element? Depending on the information you are given there can be many different ways to find the neutrons of an element. We are going to start off by finding the neutrons of an element using the periodic table. Other sections that may help you find he neutrons in a different way (starting with different…

This is one of the most difficult lessons for most students. Make sure you put a lot of effort into this lesson.   NOTE: None of the thermochemical numbers for the Δ H of chemical equations are true (EXCEPT NUMBERS ON OR THAT COME FROM THE Δ H or Δ G or Δ S TABLES). Also when I say that a certain equation is endothermic or exothermic I assigned these distinctions to demonstrate an example. I never actually looked them up in a book to see…

  What is light? VIDEO Explanation of light. The technical name for light is electromagnetic radiation. Light is made up of tiny particles (spheres) called photons and is a form of energy. The sensation you get of feeling warmth on your skin when you walk outside on a sunny day is actually billions and billions of photon particles smashing into your skin and the reaction of your nerves sensing them. So , whenever there is light around ,…

What sections should I know before attempting to learn this section? —> Orbitals Part 1 —> Energy Level Part 2 —> Complete Electron Configuration Part 3 —> Electron Configuration Diagram Part 5 —> Quantum Numbers Part 1 (n) —> Quantum Numbers Part 2 (L) —> Quantum Numbers Part 3 (mL ) —> Quantum Numbers Part 4 (ms ) —> Quantum Numbers Part 5 (All Together)  …

What are freezing point depression and boiling point elevation? Freezing point depression and boiling point elevation are talking about how you take a solution and influence it to change its freezing point (freezing temperature) or boiling point (boiling temperature). The freezing point and the boiling point change when you add more of either the solute or the solvent to the solution therefore, changing it’s molality. The vast majority of the…

What is the lesson about? This lesson is about how the properties of the small molecules relate to the properties of the large objects we interact with. We can learn how to manipulate these properties to our advantage in order to produce the exact state of any chemical we desire. At a gym we can go from a steam room to swimming pool to drinking a cup of water with ice in it. All of those were examples of one chemical H 2 O, b ut each of them…

  One representation or function that a lot of people can be unfamiliar with is the exponent. Simply put, exponents are causing a chain of multiplication events. For example, 10 with an exponent of 6 (looks like this: 10 6 or 10^6) means that you take 10 and multiply it by 10, 6 times in a row. The formula is: 10*10*10*10*10*10. Exponents can also appear with a negative in front of them, like 10-4. The formula for this one is: 10 / 10 / 10…

What sections should I know before attempting to learn this section? —> Introduction to Units —> Unit Prefixes   How do you solve word problems in chemistry? Perhaps the most fundamental problem that most students have in chemistry is the lack of problem solving and organizational skills. I can never overstate how crucial these skills are for doing well in chemistry (and in life). One of the few regrets in all my life is…

What is a solution? Unfortunately there are many definitions you have to learn in the solution lesson before you can move on any further. If you do not learn them first they will be handicapped the rest of the lesson. First we will focus on the definition of a solution. A solution is when two or more substances are mixed together on a molecular level. D ifferent parts of a solution are not able to be separate d simply by waiting for them to…

What is entropy? It is one of the most confusing scientific t erms, but it is also one of the concepts that people are most familiar with. Entropy is the measure of disorder. As time goes on the entropy of all things will increase . All things will become more disorderly. Something with more entropy (more disorderly) has a higher value (number) associated with it. Something with less entropy (more orderly) has a lower value (number) associated…

What sections should I know before attempting to learn this section? —> Covalent, Ionic, and Metallic Bonds —> Forming Ionic Compounds —> Breaking Apart Ionic Compounds   How do you use an ionic name to create the ionic compound with transition metals? Now let’s try answering the problems in the other direction (having the ionic name and creating the compound). Remember to count up all the charges and total them…