Chemistry Made Easy

 Hello, welcome to today’s lesson. I believe that this series is making a lot of sense to you. Yesterday, we showed that in order to have a substance behave as a Lewis acid, then the substance would have to possess a central atom that has an empty orbital into which it can be able to receive an electron pair. We can never stop repeating this fact because it is the most fundamental fact that you need to know about Lewis acids. We also showed that BF3 and AlCl3 could all act as Lewis acids because we established the fact that there is a free 2pz and 3pz orbital on the central boron and aluminum atoms respectively. This is the orbital into which the electron pair is received when the BF3 or AlCl3 acts as a Lewis acid. Here we have shown the reaction of ammonia with BF3 and AlCl3. In either case, we can see that what is going on actually the formation of a dative or coordinate covalent bond (Refer to the earlier lesson on the formation of H3O^+ ion). The ammonia molecule has a lone pair o

 Hello fam, yesterday, we began our study on the Lewis idea of acids. We said yesterday that acids in the Lewis sense must contain an atom that has an empty orbital. This orbital must be able to accommodate a lone pair of electrons. Recall the analogy of Mr. Smith yesterday? The entire compound of No. 38 Bronx street can be regarded as the atom as a whole. All the floors of the sky scrapper located on the property can be seen as the energy levels in the atom. The eight floor is the arena where we are most likely to find Mr. Smith. This could be the energy level where an electron occupies. The rooms on the floors where individual offices are located are the energy sublevels (orbitals) within that energy level. What if all the rooms on the eight floor in the building at No. 38 Bronx street are not occupied? There just happens to be one room that is empty where we can gather and eat lunch if we like without disturbing the work of the organization that occupies the complex? That free room

 Hello fam! Welcome to today’s lesson. We started to look at the concept of acid definition in yesterday’s lesson. We saw yesterday that acids have been defined by Arrhenius and BrØnsted – Lowry. The Arrhenius definition is limited in the sense that it does not account for behavior of acids in nonaqueous media. Did you try the assignment yesterday? The answers are attached to this post. I believe that the concept of proton donation is now clear to you after looking at the images attached. Reach out to me if you have any challenge. Now let us talk about the Lewis definition of acids. This definition of acids was put out by G. N Lewis in 1923. There is a foundation that we need in order to have an understanding of the idea that was put forward by Lewis.  There is something called an orbital in an atom. It is a region in space where there is a high probability of finding the electron. Now let us assume that your office is at No.38 Bronx street. I may not find you everywhere in the compoun

 Today is yet another interesting study as we continue to talk about acids. I hope we all have been learning something and I anticipate your feedback via the comments section, messenger, WhatsApp and text messages/calls. In one of the previous lessons, I mentioned something about the Arrhenius definition of acids. I did write that the Arrhenius definition of acids is only one of the definitions of acids that exist. Can you remember the Arrhenius definition of acids? I would remind you in the course of this lesson in case you have forgotten. You may also want to go over the earlier lessons to have a quick recap of that concept. So let’s begin! How many definitions of acid are there? We shall find out in a jiffy!  1) Arrhenius definition: Let me take you back to something we talked about sometime ago. The Arrhenius definition looks at an acid as a substance that produces hydrogen ion as its only positive ion when dissolved in water. So far we have only looked at acids from the Arrhenius

 Today we would look at the preparation of acids. Remember I told you that most of the acids occur in nature and that they may also be prepared in the laboratory. In the first few lessons, we showed that the so called vital force theory that opined that organic compounds were synthesized as a result of some vital force in living things is a fallacy. Organic compounds just like any other compound can be synthesized in the laboratory. However, our discussion here would be limited to the synthesis of mineral acids. You would recall that mineral acids are the acids that are prepared in the laboratory. As such, we are going to use the usual laboratory methods that we are conversant with to make up these acids. Methods of preparing Mineral acids; 1) Dissolving acid anhydride in water: The term acid anhydride refers to a substance that is dissolved in water to give an acid. Many of oxides of non metals are acid anhydrides. Let us look at two examples; i) CO2(g) + H2O(l) ---> H2CO3(aq) ii)

 Hello fam, hope we are getting something from the lessons so far? Let’s now get into the idea of the basicity of an acid. We define the basicity of an acid as the number of replaceable hydrogen atoms in one molecule of the acid. Let’s put it this way; you have many clothes in your house but not all your clothes are meant to be worn outdoors. I am sure that you do not go to your office or school wearing a pyjamas. Is your pyjamas not a cloth? It sure is but it’s not the kind of cloth that should be worn outdoors. Now you get my point? I am sure you do! If you still don’t get it then reach me via whatsapp, messenger or calls/text. So an acid may have many hydrogen atoms in a molecule of acid but not all the hydrogen atoms in the acid can be replaced by another positive ion when a salt is formed. Remember our definition of a salt yesterday? You may want to quickly review our lesson yesterday to check up that detail. We can also look at the basicity of the acid as the number of hydrogen i

  Hello fam, we are at it again! Like I said yesterday, the discussion today would focus on the properties of acids. By properties, I mean those things that make acids unique. The way acids behave. We would look at them individually in this study. The properties of acids could be physical or chemical. Chemical properties are characteristics that can be seen or measured as a result of a substance's chemical transformation. Physical properties are characteristics that can be seen without carrying out a chemical reaction. Thus a chemical change is a property that must be demonstrated through a chemical reaction. Physical properties of acids The following are the physical properties of acids; 1) A dilute acid would have a sour taste. Have you ever tasted vinegar? That’s a sample of acetic acid and it tastes sour right? 2) Acids turn blue litmus paper red. A litmus paper is a strip of paper that is composed of an organic dye that changes color in response to the concentration of the hyd

 Hello fam! Yes,  we are almost there! Our discussion on acids would soon be wrapped up. I hope you are learning something? After our discussion on acids, we would discuss bases, pH, buffers, salts, titration curves and everything else that relates to these. We have a long ride ahead of us so relax and enjoy the journey! You would certainly agree with me that chemistry is indeed fun. Do I have a witness in the house? Today I want to start talking about the properties of acids. Before I get into that, let me touch on something. An acid  could be dilute or concentrated. A concentrated acid is an acid that contains more acid molecules than water molecules. A dilute acid is an acid that contains more water molecules than acid molecules. Meanwhile, we need to understand the concept of concentration in chemistry. I have noticed over my ten years of teaching science and mathematics that a lot of folks use terms that they do not know the meaning. This makes deep comprehension of topics in the

 Hello fam! I trust you woke up strong and ready for the day today. I didn’t see your comments in answer to the question of yesterday so I would post the detailed answer at the end of today’s lesson. Like I told you, we would deal with the idea of percent ionization of a weak acid today. Remember that we have established long before that a weak acid would only dissociate to a very small extent when dissolved in water. The extent to which the weak acid can ionize or dissociate in solution can be expressed as a percentage. This percentage is what we call the percentage dissociation of the weak acid. In the simplest terms, the percentage dissociation is the percentage of the ions A- and H3O+ that are formed when the acid is dissolved in water. Here I have written a simplified formula for the percentage dissociation of a weak acid. I have avoided all the intricate processes of deriving the final equation and I have simply given the result of the derivation for simplicity. The formula for t

 Hello fam, today is yet another day! As I informed you yesterday, today we are going to take an example in which the Ka is given and we would need to obtain the equilibrium concentration of either of the ions H3O^+ and A-.  I hope all these are making sense? If you are confused, feel free to reach out to me via the comments section, Whatsapp or messenger. We also take phone calls and text messages on our dedicated phone number displayed on the page.  Now lets look at this example. Question; Vinegar is a dilute solution of acetic acid(HC2H3O2). If the concentration of HC2H3O2 in a vinegar solution is 0.210 M, calculate the concentration of the C2H3O2^- ion present. (Ka for acetic acid = 1.75 * 10^-5) Solution; As we saw yesterday, we would have to set up the ICE table in order to help us to navigate the solution to the problem. If we set up the ICE table, then we would have that;               HC2H3O2(aq) + H2O(l) <---> C2H3O2^-(aq) + H3O^+(aq) I            0.210                 

 Hello fam, we are here again! Today we would delve further into the concept of the acid dissociation constant. It is imperative that we note that the acid dissociation constant is an example of an equilibrium constant. It reflects the concentrations of the species involved when equilibrium has been attained. Remember that equilibrium is attained in the system when the rate of forward reaction is equal to the rate of reverse reaction. This implies that the reactants are being converted to products just as fast as the products are being changed back to reactants. The implication of this is that the concentration of each of the species in the reaction system remains fairly the same unless something disturbs this equilibrium. Before we proceed further in this discussion, it is important to note that the value of Ka does not depend on the initial concentration of the acid. This is because, we can only define the Ka at a point when the concentration of the system is no more changing drastic

  Hello fam, we are making significant progress so far and that’s really impressive ! So far we have covered the basics of the concept of acids and we are moving on to look at the acid dissociation constant which is the dividing line between strong acids and weak acids. Let me do a little bit of recap from yesterday’s lesson. We agreed that what makes an acid to “behave” like an acid is because it is able to interact in a special way with water via dative bonding. When this occurs, hydrogen ion from the acid can accept lone pairs from oxygen and then we would have H3O+ in which all three atoms of hydrogen and one atom of oxygen obey the octet rule respectively. Let me harp a little more on the idea of ‘lone pair’ because I believe the term may not have been well understood in yesterday’s lesson. Let me take you back to the electron configuration of oxygen; 1s^2 2s2 2px^2 2py^1 2pz^1(written in the most basic form as 1s^2 2s^2 2p^4). Recall that the p sublevel is composed of three orbit

  Hello fam, today’s lesson is going to focus on an introduction to another way that we can define the acid dissociation constant Ka. We would recall that yesterday, we showed that if we have a hypothetical weak acid whose formula can be given as HA, then the dissociation of the weak acid would give rise to an equation that looks thus; HA(aq) <----> H+(aq) + A-(aq) In that case we can write the equilibrium constant that shows the dissociation of the weak acid as; Ka = [H+] [A-]/[HA] Now let’s take the matter a bit further. In an earlier lesson I mentioned that an acid can only show acidic properties when it is dissolved in water. I mentioned in that lesson that gaseous HCl is not an acid until the gas interacts with water. Why would gaseous HCl not show the properties of an acid? That is one of the points that we would clarify in this lesson. Let us go back to our hypothetical acid HA. One of the popular definitions of an acid was given by Arrhenius. In his definition, he said th