INTRODUCCIÓN A LA QUÍMICA BÁSICA

Well, let's talk a little about basic chemistry. What is chemistry? Chemistry can be defined as the science that studies the changes and transformations that matter suffers. And we will always relate matter that is made up of atoms. Living matter is made up of other types of compounds, also made up of atoms, that form more complex compounds called biomolecules, such as carbohydrates, lipids, proteins, ADN, ARN, among others.

Matter is everything that has mass and occupies a place in space, that is, everything we can touch, see is matter, everything that has density and matter as I had said before is made up of atoms. The states of matter we can observe in this graph the most relevant or most common, then we have the liquid state, we have the solid state and the gaseous state.

So if we want any of these states we can get the matter, if we can go from one state to another, for example from liquid to solid is called solidification, on the contrary from solid to liquid is called fusion, from solid to gas without going through liquid is called sublimation, from gas to liquid to solid is called crystallization, from gas to liquid condensation and from liquid to gas vaporization.

Now let's look at the characteristics of each of the states. We have the solid state, which is the rigid state of matter. The particles that make it, that constitute it, are organized and very compact. We have the liquid state. The liquids are characterized because they do not have a defined form. They take the form of the container that contains them. The gaseous state, which is the state in which the particles are further apart, begin to collide and produce energy.

We have the state of plasma that we do not find in the previous graph and then we can define it as a gaseous, which the atoms that make it are separated from the electrons. And we have the Bose-Einstein condensate that reaches near zero absolute, minus 273 degrees Celsius and this is characterized because all the particles that constitute matter will try to occupy the same space as observed here. This would be the Bose-Einstein condensate.

matter has several properties we have the intensive properties that are the substance's properties such as density, fusion point, boiling point, conductivity, color, smell, flavor, etc. and we have the extensive properties that depend on the amount of substance such as size, shape, inertia, mass, etc.

Intensities of matter. We have density and density is an important property that we define as the relationship that exists between the mass and the volume. And in this table we can observe the densities of some common substances that we find that we can see in everyday life.

matter is classified into substances and mixtures substances can be simple or compound the simple are all the elements that we find in the periodic table and the compounds in the sum of two or more elements to form a chemical compound mixtures can be homogeneous if they consist of a single phase and or heterogeneous if they consist of several phases of two or more phases

Well, the atom is the smallest particle in matter that cannot be divided. The atom is made up of several subatomic particles also, which are called in the case of protons with positive charge that we find in the nucleus of the atom. We also have in this place, we can find neutrons that do not have charge, and in the periphery, which are rotating according to some atomic models, we have the electrons, which have negative charge.

well the separation techniques are techniques that can help us to purify some substance within these we have some examples here we have for example if we want to separate solids we can use the sieved or sifted clove then the property of different grain sizes such as gravel and sand the solids can also use the extraction, floating, magnetization but we are going to focus only on some very specific ones

We have for example decantation, in this one we are observing that we use a decantation blower and we obtain a liquid that has a degree of impurity. Then we add this liquid to another substance in the same decantation blower, two liquids that are invisible, that is, they do not mix.

and we shake it so that the impurities mix in both places and then we separate one of the two substances and thus we continue to purify this is called decantation

we have the distillation that is a separation technique that is based on the different boiling points of the substances that we have here an example of this we can do we can distill water to remove all the minerals we can distill a mixture of water alcohol to separate the alcohol from the water to purify some type of substance the importance of this technique or the foundation of this technique is that the substances that we are going to separate must have different boiling points

We have the filtration, which is another separation technique in which we pass a substance that is in a semi-solid state or liquid with impurities and we pass it through a filter paper and here are going to be the particles of high molecular weight or larger than the size of the filter and here we are going to pass the filtering.

We have the centrifugation, which is one of the most important and most used techniques in biochemistry. We take a sample of venous blood or blood. Then we add it to a test tube that can have anticoagulants or it can be a dry tube, depending on the technique that we are going to perform. We pass a device called the centrifuge that will apply centrifugal force to this. It will turn it up to high revolutions.

for 5 to 10 minutes and then we keep it that the solid particles, red blood cells, white platelets, will be in the bottom of the tube and in the upper part will be the liquid part of the blood that we call serum if we take it with a dry tube or it is called plasma if the tube previously had anticoagulant.

We have the chromatography technique, which is also an important separation technique in which we take a sample of a substance that we want to separate, see how it is molecularly composed. Then we put it on the filter paper or on the chromatography plate. Then we put it here, here there must be a liquid in which the molecules do not mix with that liquid.

After a while, the molecules will separate and migrate in this way as we see here. Then this filter paper or chromatographic plate is transferred to the gas chromatograph, a gas chromatography equipment. To give an example, there are many types of chromatography. Then this technique burns this molecule, this substance burns it and decomposes all the particles that make it up. And then we will observe in the computer peaks in this way.

and the computer compares them with the graphs that show different substances. This is a very important technique for when we want to analyze how a substance is composed, a drug, in case of intoxication, in case of homicide, the sample can be analyzed by this technique. A very reliable technique. Let's talk a little about temperature scales.

So we must talk a little about energy, heat and temperature. Heat is a type of energy transmitted by shocks and is generally given in the periphery of the substance. So here we can observe that the molecule is water.

We are barely applying heat, but when the temperature increases, then the molecules begin to collide, to rotate and some begin to come out because they no longer feel that they do not fit in the container or they try to occupy the gases, trying to occupy much more space than they would occupy in the liquid state because their molecules move away a lot. Well, there are many temperature scales.

but the most common ones that we can see are the Fahrenheit scale, Celsius scale and Kelvin scale. Here we have each of the designers of each of the scales. The important thing is that we can see that 32 GF equals 0 C which is the scale that we use in Colombia. We also have that 0 C equals 273 K.

Here we have some of the formulas that we are going to work with to solve the exercises. But let's focus more than anything on how to solve the exercises. So here we have that we are going to pass 35 degrees Celsius to Fahrenheit degrees. So the formula we are going to work with is Fahrenheit is equal to 9/5 times Celsius plus 32. What is it that we should do in this formula? We already have the formula here, we must replace this 35

we will place where the degree Celsius and then we complete the whole operation well what happens here here we are seeing

that Fahrenheit is equal to 9/5 the same for 35 and is replaced +32 but we here is a parenthesis what does this parenthesis mean that first we must multiply 9/5 by 35 and the result we will add +32 but first we must solve the parenthesis parenthesis is the priority of the operation then it turns out that this gives us 9/5 by 35 gives us 63

and here we can break the parenthesis and add it, plus 32 gives us 95 degrees Fahrenheit. Well, here we have another one, we are going to pass minus 5 degrees Celsius to Fahrenheit degrees, then we say Fahrenheit is equal to 9/5 times Celsius plus 32, we must replace the minus 5, we must place it here.

Here we have it, Fahrenheit equals 9/5 times -5 degrees Celsius plus 32. We solve the parenthesis. How do we solve this? We multiply 9 times 5 by 5. That equals, then, and we add it, plus 32. Let's see that here we must respect the law of signs. 9/5 times 5 is equal to -9 plus 32. This is a subtraction. So it gives 23.

In this other example it says to pass 50°F to degrees Celsius. So the formula is 5/9, open parentheses, times Fahrenheit, minus 32. So here we must replace the 50 Fahrenheit by the F that is here. How does that give us? 5/9 is going to be equal, open parentheses, 5/9, open parentheses, 50°F, minus 32.

just as the previous we must respect the parenthesis this is the first thing we are going to do that is 50 minus 32 that gives us 18 positive because 50 is greater than 32 and this is multiplied by 5 9 5 times 18 between 9 that gives us 10

here we have another we can see this this type of example pass 0 Fahrenheit to Celsius never give us fear when we see these 0 is a temperature 0 degrees Celsius 0 degrees Fahrenheit is a temperature ok from 0 degrees Fahrenheit to degrees Celsius formula is 5/9 open parentheses Fahrenheit minus 32 here where the f goes we must place the 0 then here we have it 5/9 open parentheses 0 Fahrenheit minus 32

that equals 5/9 times -32 that gives us -17.17 now in this example we have that we are going to pass 5 Kelvin degrees to ranking degrees so the formula is ranking equals 5/9 times Kelvin degrees here what we have to do is replace Kelvin degrees by this one here, the same that we saw here 9/5 times 5 that gives us 9 9 ranking degrees in this we are going to pass 20 ranking to Kelvin

We say that Kelvin is equal to 5/9 by ranking 5/9 by 20, we replace this in this place that would be 20 ranking Kelvin is equal to 11.11. This is all for today. Thank you very much.