L- 8 | GSSSB सहज सफलता Junior Pharmacist 2026 | Physical Pharmacy: States of Matter & Properties

[00:00:00]Hello everyone, welcome back to GDC classes. I welcome you all to another session where today we are going to talk about the states of matter of physical pharmacy.

[00:00:08]And all your questions have been picked from important topics only.

[00:00:14]So, I hope your preparation is going well. And all the questions you will be asked here will be with the explanation. Please note down those which seem suitable to you.

[00:00:24]If you know it, it is best, if you don't know it, if you find the concept new, then definitely note it down. Ok? So, let's start with our first question. The first question is that some forces are also known as now you all should remember when we talk about intermolecular forces. This is a question of 2025 only.

[00:00:45]In intermolecular forces, we see that they are either between two polar molecules.

[00:00:51]So you call it dipole dipole interactions or it would be between your two non-polar molecules which we would call induced dipole induced dipole type interaction which you also call London forces, right or it would be between ah dipole and induced dipole which you also call D by forces. So overall, what would be the key forces? Dipole dipole interaction forces. What will happen? Dipole Dipole Interactive Forces. So your correct answer will be option D for Keysome Forces. This is a question of 2025. Please note it carefully.

[00:01:24]Alright? Let's move on to our next question and you must note down its explanation.

[00:01:33]Also note the energy of attraction.

[00:01:34]That is one to 7 kilocalories per mole. Ok? It is between two polar molecules. Ok? Let go.

[00:01:45][nasal sound] Yes. So the second question is anesthetic ether becomes gas when pressure is decreased, temperature is increased, volume is decreased and concentration is increased. When gas is formed, it is obvious, what will you do as soon as it is formed? Will change the temperature. That means, what will happen after you increase the temperature? Which is anesthetic ether that will convert into a gas. That will convert into a gas.

[00:02:17]So what will happen if the temperature is increased? The particle will gain motion. Kinetic energy will be acquired due to which its state will change.

[00:02:26]Alright? Let go.

[00:02:31][nasal sound] Let's move on to the next question.

[00:02:35][nasal noise] OK.

[00:02:39]Gas molecules exhibit continuous random motion due to what we just discussed as the temperature is increased.

[00:02:48]What do molecules do? Kinetic energy is acquired. That means random motion starts because of increasing temperature. The orientation and movement of the particle increases very rapidly.

[00:02:58]And when it comes to motion or movement, there we talk about none other than the kinetic energy. What will remain? Kinetic energy. So part gas molecules exhibit continuous random motion due to the kinetic energy. Ok? I do n't know why this next one is not happening.

[00:03:18]Okay, no problem, let's do it like this. Yes.

[00:03:21]So what will be your option? Your option will be kinetic energy. Option number C. I just told you about kinetic energy. Let go.

[00:03:29]Come to the next question.

[00:03:31]Come to the next question. Yes.

[00:03:34]So the question says the heat energy that is required to change the state of the matter without raising the temperature. What would you call it, specific heat, latent heat, sensible heat and thermal heat. First of all, whenever the state of any matter changes from state A to state B, for example, let us take melting of ice here, which happens at 0 degree Celsius. So, until all your ice is converted into water, the temperature does not increase, till then the reason being, all the heat energy that you are supplying is being used, it is being used in the change of state here, why is it being used, it is being used in the change of state, so without increasing the temperature, what is happening to you, the state of the matter changes, so you call this heat latent heat, what do you call latent heat, so, all the energy that you have supplied is used up in changing the state of the matter without changing the temperature. Ok? Okay, let's move on to the next question. Yes.

[00:04:40]Which of the following is the application of ideal gas constant? Now the ideal gas constant is r pv = nrt, so you study it in gas laws, you also study it in electric electro chemistry, you also study it in solution chemistry and you also study it in colloidal chemistry. So this is an overall generalized concept. So what will be the correct answer? Option number D.

[00:05:03]What will happen? Option number D. Ok? So please comment down quickly about the Universal Gas Constant, its units and value.

[00:05:11]Unit and value. Alright? Let's move on to the next question. Come to the next question.

[00:05:16]So the question says Dalton's law is strictly obeyed by Dalton's law is strictly obeyed by what?

[00:05:26]What was Dalton's Law? You have to remember the gas law.

[00:05:28]What was Delt's Law based on? Dalton's law was based on the partial pressure. It was based on the partial pressure. Right? So the Wonder Wall equation was for your real gas.

[00:05:37]What were the rest of us doing?

[00:05:39]Trying to understand ideal gas behavior.

[00:05:42]Right, right? So what was Dalton's Law based on? Dalton's law was based on the partial pressure. So your correct answer will be option number B. What will happen? What will be the total vapor pressure in a mixture of gases?

[00:05:56]Add up your partial vapor pressure for all the components.

[00:05:58]Ok? Let's move on to the next question.

[00:06:01]On to the next question. So the question says the process by which liquid changes into solid upon heating is none as liquid changes into solid. Now do you have to take into account the interconversion state of matter?

[00:06:20]What do you call a solid to liquid?

[00:06:21]You call solid to liquid melting or fusion. What do you call a gas from a liquid? Boiling or vaporization.

[00:06:29]What would you call the liquid that leaks back from the gas? The conversion of gas back to liquid is called condensation. And what would you call a solid back from a liquid? We will say freezing. There is another process in which solid substance is directly converted into gas which you call sublimation. So here the liquid changes into solid, right? So what will be your correct answer? It is given upside down. It is given upside down. The fuse is given in the answer. While what is fusion? Solid to liquid.

[00:06:57]What is a fuse? Solid to liquid. Ok? So fusion is also called your liquid and your freezing will turn liquid into solid.

[00:07:05]Ok? All right. Okay, let's move on to the next question.

[00:07:12]Let me fix its fonts first. Okay, let's move on to the next question. The Clausius-Clapeyron equation is primarily used to determine what? Now this is a question that has been asked many times.

[00:07:25]And from here comes the direct question. The best way to remember equations is to write down each equation on a separate page which you should revise timely weekly or everyday, which should include the expression of the equation plus what you should do with it.

[00:07:42]Also, please add what this equation is for. Ok? So what is the Clausius- Kapron equation for?

[00:07:48]Basically molar heat of vaporization. Well, generally in this you see the relation of vapor pressure as well as temperature.

[00:07:56]And your heat of vaporization also comes into this equation. Look at this, pay attention. This is where vapor pressure, molar heat of vaporization and temperature come into play.

[00:08:03]Right? So this is Clausius Clapeyron equation. Ok? Next question.

[00:08:08]According to Gram's law, the rate of diffusion of a gas is inversely proportional to what? I told you gas laws are very important. Cover everything once with their equations. So Gram's law is basically for diffusion, which depends on what? of gas molecules over the molecular mass.

[00:08:27]Right? So it will be directly the square root of its molecular mass. Option number C will be corrected.

[00:08:34]This is your equation and here you can see the rate of drug diffusion which will be inversely proportional to the molecular mass of the gas.

[00:08:42]Ok? Come on next question. Which of the following gases has the lowest critical temperature?

[00:08:49]Ammonia, carbon dioxide, hydrogen, and sulfur dioxide, right? So it is very important for us to remember the values ​​of critical temperature.

[00:09:00]I will provide you a table after this where you can note them down in a better way. Right?

[00:09:06]So the correct answer here will be hydrogen.

[00:09:08]Ok? So here you have to pay attention to hydrogen, nitrogen, oxygen, pay attention to this point first. Now the critical point of all this is that it is actually very low, what will happen because of it? These cannot be liquefied. On the quantity of gases like sulfur dioxide, carbon dioxide, nitric oxide, these can be liquefied, right? So, a gas will be cool below its critical temperature, then less of the pressure will be required to liquefy. But if the bead falls even lower than that then it will not be possible to liquefy. Ok? So you will get to know the names of gases here. Their critical point will be very low. Clausius-Clapeyron equation is used to express the relationship between I just told you that Clausius-Clapeyron equation is a very important equation where vapor pressure and absolute temperature have to be taken into account.

[00:09:58]Ok? Vapor pressure and absolute temperature. We also covered expressions before. So, the correct answer will be option number A. Ok? This is the equation we just covered. Come on next question. Which of the following is not the principal involved in the liquefaction of gases?

[00:10:16]Generally, what is one principle of liquefaction of gases that we have just seen?

[00:10:20]Critical point. Second is Joule Thomson effect. Where your gas cools down due to rapid expansion.

[00:10:27]Right? So rapid expansion which results in cooling and ultimately liquefying.

[00:10:32]Ok? So critical condition June Thomson and third will be inversion temperature. Third will be inversion temperature. Ok? So all three of these will remain your principles but the boil temperature will not remain the principle. Ok?

[00:10:46]Option number D is incorrect because your correct answer is here. Ok?

[00:10:52]Next. Inversion temperature is defined as a temperature below which a gas. We just read that we have three principals. Which ones? We studied the Joule Thomson effect. Inversion temperature or critical point. Which is the inversion temperature that is also based on before of the cooling that you get from the Joule Thomson expansion, right? So it is ultimately based on the phenomenon of Joule Thomson effect only. Ok? So, this is a direct question. Now from here you have to keep in mind that below the inversion temperature the gas will cool on the expansion. Above the inversion temperature gas will heat on expansion at the inversion temperature there will be no change.

[00:11:29]Ok? So keep these three points in mind that what are you ultimately talking about in inversion temperature?

[00:11:35]Rapid expansion of gas which will result in cooling which was your Joule Thomson effect.

[00:11:40]Ok? Come on next.

[00:11:43]The smallest geometrical repeating unit in a crystal is non-age. When we talk about a crystal, its smallest part is its smallest crystal unit, which is a unit cell.

[00:11:55]What do you call its external appearance? Crystal Habit. Ok? So, the smallest ah geometrical repeating unit will be known as the unit cell. It will be known as the unit cell. Look here there is a unit cell and all these unit cells are formed in a repeated pattern. That ultimately forms a crystal structure.

[00:12:13]All right. Let go. Come next. This equation is non- age three times the same question has been asked in different ways.

[00:12:21]So you can understand why I told you that writing equations is very important. Ok? So this equation is ultimately between the Clapeyron equation that explains the relationship between absolute temperature and pressure. Right? So vapor pressure and absolute temperature and your heat of vaporization. Ok? Let's move on to the next question. In this super critical fluid extraction, the critical temperature and critical pressure for carbon dioxide. Generally, I will tell you about two-three gases, it is important to write them.

[00:12:58]Questions come from carbon dioxide also, a direct question has come from carbon dioxide also, generally what is its pressure, the pressure will be 74 atm and the temperature will be 31 degree Celsius, right, so the critical temperature is 31 degree Celsius, the critical pressure is 74 atm, okay, come next, what will be the triple point of water? The triple point will be the point where all three states exist.

[00:13:21]Solid, liquid and gas.

[00:13:24]So that temperature value for water is 0.0098 degree Celsius and 4.58 mm of HG pressure. Ok? Now all the options here seem almost the same. We have to focus only on the unit. Now here it is 0.098 so there is one zero missing here. Because of this this option became incorrect. Now here is 0.0098 degrees Fahrenheit. I told you degrees Celsius. It's Fahrenheit here too.

[00:13:52]So what is our correct answer?

[00:13:54]Option number D. What do children generally do in such questions?

[00:13:58]In the rush to tick the answer directly, we do not see the difference in the options. So always wait 30 seconds beforehand.

[00:14:06]Read the question carefully. AcceptFalse statement. Is there any other tricky question like this?

[00:14:10]Ok? So you see this water face diagram. There's Ice Liquid here and Water Face Fuzz here. And here's your triple point in the middle. Ok? So what was your triple point? Generally 0.0098° C and 4.58 mmag of pressure there.

[00:14:25]Ok? For water. Come on next question.

[00:14:28]What is the quarters method used for? Direct questions come.

[00:14:32]Remember depression of freezing point. Ok? and elevation of boiling point.

[00:14:36]Questions on these methods come up very often.

[00:14:39]So you have ah which is sodium chloride equivalent methods. Ok? Ah White Vincent methods are all these you should remember classification methods.

[00:14:50]So what is the Cottle's method based on?

[00:14:51]Elevation in the Boiling Point. Elevation in the Boiling Point. Ok? Come next.

[00:14:59]What are the types of liquid crystals? Look, there are three types of liquid crystals. The first is nematic. The second one is symmetric. The third is cholesteric. What does nematic contain?

[00:15:08]In nematic, generally the molecules are arranged parallel to you. Ok? In which the mobility of your molecules is restricted. Similarly, your thread-like arrangement is called nematic. On the other hand, symmetric liquid crystals are called soap-like and greasy molecules.

[00:15:26]Where there is a layered arrangement.

[00:15:28]Ok? There too, there is restricted movement and rotation is possible in only one direction. The third is cholesteric combination of both in which a 180° turn is possible. Ok? So it will be a 180° turn. Both parallel and layered come to you separately. So in nematic, as I told you, the parallel arrangement gets layered in symmetric and in cholesteric, the combination of both is nematic symmetric nematic symmetric. So here's your cholesteric one. Ok? Come next. Molecules in the symmetric liquid crystals are characterized by which of the following?

[00:16:01]I just showed you nematic, cymatic cholisteric nematic is thread like, parallelly arranged, cymatic is layered.

[00:16:08]Ok? So what would happen inside a nematic crystal? The mobility you have here is rotation possible around one axis, okay? And movement is restricted in one axis. Ok? What is there even here?

[00:16:22]Rotation is possible in around one axis. And here a 180 turn of the molecule is possible. So mobility in three directions and rotation in one axis.

[00:16:31]Mobility in Two Directions and Rotation in One Axis in SIMATIC. Remember this. If no rotation is given in other options then it is wrong. Within cymatic, mobility occurs in two directions and rotation occurs in one axis. On the other hand what is mobility in nematic? It happens in three directions and rotation is possible in one axis. So it will be mobility in two directions and rotation in one axis. Ok? Come on next question. Crystalline solids are non- isotropic and pseudo-solids.

[00:17:07]What do you call crystalline solids? Let's say pseudo-solids.

[00:17:09]Right? What do you call a similar amphorae? Amphoras are called super cooled liquids. Ok? So crystalline solids will be your true solids, right, and the immortal ones are pseudo solids.

[00:17:21]So this is what happened to Amarfas. So option C D got cut. Crystallines are N isotropic and amorphous isotropic. That means different properties in the different directions which is a statement for the crystalline. So crystalline are an isotropic while the ah immortal one are ah isotropic crystalline one is an isotropic. You call crystalline as true solids and immortals as pseudo solids. Ok? Come next. Crystal form of sulfacetamide. Generally when you study Bravais lattices you are talking about crystal systems. Cubic, orthorhombic, monoclinic, rhombohedral.

[00:17:55]Ok? Triclinic happened. So sulpha acidamide, which is a specific example, will be orthobic. Of. Please note it. This question has also been seen repeatedly in many different exams.

[00:18:03]Ok? Orthoerobic.

[00:18:06]Here you can see that both barium sulfate and sulfacetamide are mentioned in orthorhombic. Similarly, the question arises on rhombohedral. Isorthymol is done. There has been an important question regarding urea.

[00:18:17]Tetragonal sodium chloride became cubic potassium chloride. Right? So Effidon hydrochloride became monoclinic.

[00:18:22]Please write down these important examples.

[00:18:25]Ok? Come next. Keysome Interactive Forces. I had said this same statement in your first question. The interactive forces that will occur between polar molecules i.e. dipole dipoles will be called these forces.

[00:18:38]What is their energy value? One to 7 kcal per mole. Ok? This question has been repeated. Come on next.

[00:18:46]What is the term apparent solubility used for? The solute concentration is lower than the saturable concentration. The system exhibits higher concentration than the saturated solution. The drug becomes insoluble and the solvent evaporates rapidly. So its correct answer will be option number B Apparent Solvability, that is, it may not be as much as it appears or it is over estimated or under estimated. So the system will exhibit a higher concentration of solute than in the saturated solution. Therefore, apparent means that your actual value is more than the suppository value. Ok? That is why we can point to it in apparent terms. Ok? Next, recall the phase rule. Degrees of freedom f = c - p + 2 What does the degree of freedom f represent? Number of phases. Ah f represents degrees of freedom.

[00:19:42]C is the number of components, P is the phases. The question says, what does your P denote in the Gives Fuzz Rule? So, p will denote the number of phases. Ok? C what happened?

[00:19:52]Components. Which of the following is a characteristic of amorphous?

[00:19:56]What does crystalline contain? Crystalline has an ordered arrangement which is why we say it has repeating patterns.

[00:20:01]While the pattern order in the amorphous one becomes a short range order, that order gets lost very quickly. That means the repeat pattern of the molecules cannot come on the crystalline part.

[00:20:12]So the amorphous ones are isotropic. So our first option got cancelled. Crystalline arrangement which is not possible because there is no repeat pattern. Isotropic This is correct. Yes. Our symmetry is also not there in this.

[00:20:26]But isotropicity occurs inside amorphous substances. Ok?

[00:20:30]So check out the order for Emerfus and check out Crystalline. Every molecule is in a set pattern whereas this is not the case in amorphous.

[00:20:36]Ok? Let go.

[00:20:39]Identify the molecule with almost zero dipole moment or one that has none. Ok? Generally you see examples in it structure wise. If there is a linear structure in which the charge distribution is equal coming from everywhere. For example, let us take the example of benzene. Charge distribution is coming equal. Ok?

[00:20:56]We take carbon dioxide. C and here O here O. So equal charge distribution is coming. What do you do there? The dipole movement will become zero.

[00:21:04]Carbon dioxide has a 180° structure. It became benzene. Ok? Para dichloro benzene. One four became Dion.

[00:21:11]In their case, your dipole movement becomes zero. Ok? Come next.

[00:21:15]Approximate size of mycelium.

[00:21:18]When do you read Myceline? Pay attention, you must have read in surfactant that when this concentration which you call critical micellar concentration is reached then your particles get oriented in such a way in the bulk that they form micellar formation. So what is its approximate size? Around 50 angstroms will become 10 angstroms raised to the power -10. Ok? Come on, come next.

[00:21:40]The concentration at which self- association begins to form mycell.

[00:21:46]I just told you that generally when you add surfactants, they first come to the surface. Right? As you increase the concentration, their inward pull reduces because the surface tension reduces. So the molecules try to move in bulk which will happen at a particular concentration.

[00:22:02]That is known as the critical micellar concentration where CMCs will start to form. Ok? Next. Which of the following prevents the molecule from eating each other? Ok? Cohesive, adhesive, attractive, repulsive annihilating basically comes under repulsive forces.

[00:22:18]What does it come in? Comes under repulsive forces.

[00:22:20]Ok? You can see here that the meaning of annealing is that the molecule should be repelled here. So it prevents the molecule from annihilating.

[00:22:28]So for that, repulsion is advisable.

[00:22:30]So repulsive effects will occur here when molecules of similar charges are present. Ok? So that's it for today. I hope the explanation is all done.

[00:22:38]And all the topics are becoming clear to you as to where we will have the highest chances of getting questions from.

[00:22:46]Ok? So that's it for today. See you in the next video. Till then all the very best and continue your preparation for GDC.