Yes! 50 Guaranteed Marks in JUST 10 min! Wassim bhat | Re-NEET 2026

[00:00:00]My dear students, again in this particular session I will be giving you some short shot guaranteed 50 marks in just 10 to 12 minutes. So be with me till the end. These are some frequently asked questions and they are very easy questions which are asked almost every year in your need examination. First of all a question will be asked what are the examples of extensive properties and intensive properties. They'll give you the question right? They'll give you two three examples wherein you have to identify whether it is the extensive property or intensive property. So remember these examples extensive properties mass volume heat capacity enthalpy entropy gives free energy internal energy. These are the most common examples of extensive properties.

[00:00:40]Similarly intensive properties temperature density molar heat capacity specific heat capacity pH boiling point concentration as well as emf of the cell. These are the examples of your intensive property. Right? Similarly, I'll add one more term here. Molar entropy. Molar entropy. It is again one of the important examples of your intensive properties. Now, similarly, moving on to the second point. If entropy is kept as the criteria for spontaneity, then for the process to be spontaneous, what is the condition? If entropy is the only criteria for spontaneity, then remember delta s total, delta s total means delta s universe, it should be greater than zero. then only the process is going to be spontaneous. If delta S total is less than zero, process is going to be non-spontaneous. If delta S total is equal to zero, we say it's going to be reversible. Okay, this can be directly a statement based question asked in your NE 2026 examination. Okay, moving on to the third concept. They can give you any of these graphs and they'll ask you what is the order of the reaction. This 1 2 3 4 5. These five graphs are basically the graphs for the zero order reactions.

[00:01:48]Perfect. They can put any graph in the question. They'll ask you what is the order of the reaction. Remember these graphs, they are the zeroorder reaction graphs. And the graphs which are mentioned over here, they are the first order reaction graphs. Okay. Well, I'll be sharing the PDF of this particular session on my telegram. The name of the telegram channel is W was chemistry official. Wasim chemistry official is the name of the telegram channel on which you'll get this particular PDF.

[00:02:12]Well, I forgot to share the earlier two PDFs. I'll be sharing right after this particular session. Okay. in the telegram channel. Similarly guys, as I told you, these are the graphs which are basically valid for the first order reactions. Remember them as well. Now question can be asked about free expansion. How do we define free expansion? Free expansion is nothing. It is expansion in vacuum. Expansion of gas in vacuum. Expansion against zero external pressure. First thing which you have to keep in mind whenever in the question they'll mention free expansion.

[00:02:40]Whenever in the question they'll they'll mention vacuum. Remember W value is taken as zero. Now if there is isothermal free expansion of an ideal gas since the term is free expansion so w value is zero. The gas undergoing isothermal process so delta U is also zero. The ideal gas undergoing isothermal process delta U will be also zero. Now first law of thermodynamics says that delta U is equal to Q plus W.

[00:03:03]Now W is 0 delta U is zero. That means Q automatically becomes equal to zero.

[00:03:07]Right? So this is what happens in the isoothermal free expansion of an ideal gas. So they'll ask you when the ideal gas under goes isothermal free expansion what all parameters can be zero these are the parameters which can be zero here similarly adabatic free expansion of an ideal gas the term is free expansion that means w value is zero adabatic q value is zero if w is z q is zero first law says delta u is equal to q plus w so delta u is 0 now delta u itself is basically ncv delta t for the ideal gas so this has to be zero which means that delta t value is equal to zero they can ask you which all parameters are zero when the ideal gas under goes adabatic free expansion. So these are the parameters which will be zero when the gas under goes adabatic free expansion. One more short short question that can be asked. Similarly this is one more table my dear students.

[00:03:54]Perfect. From which question can be asked? If you'll be having any process for example A gives B. Let's say we have got a process A gives B. We have got a reaction A gives B. Perfect. Now during this reaction if delta H is negative delta S is positive. Delta G will automatically come out be negative and we say the reaction is spontaneous at all temperatures. Similarly, if delta H is negative, delta S, sorry, delta H is positive, delta S is negative, right?

[00:04:18]Delta G will be always positive, which means that the reaction is going to be non-spontaneous at all temperatures. If delta H is negative, delta S is negative, delta G will be only negative, right? At low temperatures. So I would say I would say that particular process for which delta H is negative delta S is negative we say that particular reaction will be spontaneous only at low temperatures. Similarly positive positive this particular reaction will be spontaneous only at high temperatures. This is again my dear students one more table from which question a theoretical question can be asked. Okay so remember this particular table as well. Moving on to the next one. Direct relation between mality and marity. This is the direct result between marity and marity. Marity is equal to 1,000 into marity of the solution divide by,000 into density of solution minus marity into molar mass of solute. For example, this survey question will be asked. Calculate the mity of 1 molar NaOH aqua solution whose density is given. So what you'll be doing? You'll write M is equal to,000 multiplied by marity is 1 divided by 1,000 * density of solution is 1 minus marity that's 1. Molar mass of solute that's 40. Just a matter of calculation.

[00:05:29]Solve this. This will give you mality of the solution. Remember this result. It's very very very important. Okay.

[00:05:35]Similarly like this there is one more result. Result between mality and mole fraction. Mality and mole fraction.

[00:05:41]Remember molity is equal to 1,000 mole fraction of solute 1 minus mole fraction of solute molar mass of solvent. This is a direct result which relates mity with mole fraction. Remember it directly. Now a question can be like this. Calculate mality of the aquas solution in which mole fraction of solute is 0.2. So what you have to do? M is equal,000 * mole fraction of solute is 0.2 divided by 1 minus mole fraction of solute is 0.2. Molar mass of solvent since it's aquis that means solvent uses water whose mass is 18. Just call this a bit of calculation and you're done.

[00:06:17]Similarly my dear students they'll ask you Lyman series falls in which which range? Balmer series falls in which range? Similarly, posture series falls in which region? Remember, you have to remember U V I I I U means ultraviolet.

[00:06:33]U means ultraviolet. V is visible. V means visible spectrum. This means infrared.

[00:06:40]This also means infrared.

[00:06:42]This also means infrared. And you can write it as far infrared as well.

[00:06:48]Perfect. If they ask you past a series falls in which region? Your answer will be infrared. Bracket series falls in which region? Infrared. Okay. Or you can far infrared as well. This is the question that is frequently asked in your neat examination as well.

[00:07:02]Similarly, a short short question that's almost asked every year. Which of the following quantum numbers is incorrect?

[00:07:08]Which of the following quantum numbers is incorrect? My dear students, N represents your principal quantum number. L is your estimal quantum number. M is your magnetic quantum number. S is your spin quantum number.

[00:07:19]Okay? And L can have values from 0 to N minus one. M can have values from minus L to plus L. S can have only two values plus 1x2 and minus 1 by 2. Now for example look at the first one. Let's check whether it's correct or not. N value is five. So the electron is present in a fifth shell. L value L is from 0 to N minus 1. So 0 to 5 minus 1.

[00:07:38]That means 0 to 4. So it can be 0 1 2 3 or four. Four is mentioned. Correct. M is from minus L to plus L. M is from minus L to plus L. So -4 to + 4, -4 to +4, right? Three comes in between. So it's correct. S can have two values plus 1 by 2 - 1 by this is correct. Okay. Now tell me whether this is correct or incorrect. This incorrect. Why is that?

[00:07:59]Because L value is from 0 to n minus 1.

[00:08:01]0 to 5 - 1. 0 to 5 - 1 means 0 to 4. So 0 1 2 3 4. It cannot be minus 4. So this incorrect, right? Similarly m value is from okay look at this one. this m uh this this principal controller that's five sical cont that's four so this is correct this is correct now minus L2 plus L this also correct plus 1x2 this also correct now look at this one here you can see spin is zero spin cannot be zero spin spin can have only two values plus 1x2 - 1x2 so this incorrect so this is how a short short question is also asked calculation of valence electrons again one simple concept my dear students you'll be given with the matter whose first ionation energy second ion energy Third and fourth will be given. We will be supposed to check how many valence electrons will be there in the atom.

[00:08:47]First ion energy means to take the electron to take the first electron out.

[00:08:51]To take the first electron out 100 electron volt energy is required. To take the second electron out 200 electron volt energy is required. To take the third electron out 300 electron volt energy is required. Now to take the fourth electron out 4,000 electron volts are required. Do you see huge jump here?

[00:09:08]Do you see huge jump here? That means the fourth electron would be present in the penultimate shell. Right? The fourth electron will be present in the penultimate shell. Right? And closer the electron towards the nucleus, more energy is required to remove this.

[00:09:21]That's why the jump here is huge. So technically I must say the fourth electron has to be taken from not from the valence shell but one shell before valence shell. That's called a penultimate shell. Perfect. So they'll ask you how many valence electrons are there. As you can see there are three valence electrons. Perfect. So these were some shortsh short 11 concepts my dear students which are almost almost asked every year and these are easy questions you can expect one two out of these concepts in the upcoming neat examination as well right share this video with all of them all of the students so that everyone gets benefited out of these videos take care god bless you all and love you all bye-bye