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Chemistry Marathon: From Polarity to p-Block (JEE/NEET PYQs) Test your knowledge on five diverse and crucial chemistry concepts. Question 1: Polarity of Molecules Choose the polar molecule from the following: (1) $CCl_4$ (2) $CO_2$ (3) $CH_2=CH_2$ (4) $CHCl_3$ Check Answer  Solution 1: Polarity Key Concept: A molecule is non-polar if its net **dipole moment ($\mu$) is zero**. This usually occurs when the molecule is highly symmetrical, canceling out all bond dipoles. $CCl_4$ (Tetrahedral), $CO_2$ (Linear), and $CH_2=CH_2$ (Planar) are highly symmetrical, so $\mu = 0$. $CHCl_3$ (Trichloromethane) has a **tetrahedral geometry**, but the central carbon is bo...

P-Block Elements Revision - JEE Advanced Level The P-block elements in the periodic table consist of elements in groups 13 to 18. These elements show a wide range of properties due to the different types of elements present (metals, non-metals, and metalloids). Understanding the unique characteristics, trends, and reactions of P-block elements is crucial for JEE Advanced preparation. For a revision of the periodic table trends, check our Periodic Table Revision Series . 1. Key Properties and Trends of P-Block Elements P-block elements exhibit varied properties based on their group and period position. Some important trends include: Property Group 13 Group 14 Group 15 Group 16 Group 17 Group 18 Metallic Character Increases down the group Decreases down the group Decreases down the group Increases down the group Decreases down the group ...

S-Block Elements Revision - JEE Advanced Level The S-block elements of the periodic table, consisting of Group 1 (alkali metals) and Group 2 (alkaline earth metals), are characterized by their distinct physical and chemical properties. Understanding their properties, trends, and reactions is crucial for JEE Advanced preparation. For a revision of the periodic table trends, check our Periodic Table Revision Series . 1. Key Properties and Trends of S-Block Elements S-block elements exhibit properties such as low ionization energies, high reactivity, and formation of ionic compounds. Some important trends include: Property Group 1 (Alkali Metals) Group 2 (Alkaline Earth Metals) Atomic Radius Increases down the group Increases down the group Ionization Energy Decreases down the group Decreases down the group Electronegativity Decreases ...

Periodic Table Revision for JEE The periodic table is one of the most fundamental concepts in chemistry, especially for students preparing for competitive exams like JEE. It provides a structured way to understand the properties, trends, and behaviors of elements. This article will help you revise the periodic table for JEE with a focus on key trends, important groups, and exam-centric insights. 1. Understanding the Periodic Table The periodic table is arranged in periods and groups, where elements are placed based on their atomic number, electronic configuration, and recurring chemical properties. Each element has a unique position that reflects its properties. Knowing these properties is crucial for solving JEE questions effectively. Quick Fact: The periodic table consists of 18 groups (vertical columns) and 7 periods (horizontal rows). Elements are categorized into metals, non-metals, metalloids, and noble gases. 2. Key Trends to Remember ...

Work, Power, and Energy Revision - JEE Advanced Level Work, Power, and Energy are fundamental concepts in mechanics. Understanding these concepts is crucial for solving problems related to energy conservation, work done by forces, and power output. In this post, we will cover the key formulas, interactive examples, and simulations to help you master these concepts. 1. Key Formulas Below is a table summarizing the important formulas related to work, power, and energy: Concept Formula Description Work Done \[ W = F \cdot d \cdot \cos(\theta) \] Work done is the product of force, displacement, and the cosine of the angle between them. Kinetic Energy \[ KE = \frac{1}{2} mv^2 \] Kinetic energy is the energy of motion, dependent on mass and velocity. Potential Energy \[ PE = mgh \] Potential energy is the energy stored due to an object...

 Q. If the shortest distance of the parabola y² = 4x from the centre of the circle x² + y²– 4x- 16y + 64 = 0 is d, then d² is equal to:   ( JEE mains 2024) A. 16 B.  24 C. 20 D. 36 Show Answer Ans:- (c) Equation of normal to parabola  y = mx-2m-m³  this normal passing through center of circle (2, 8)  8=2m-2m -m³  m =-2  So point P on parabola (am², -2am) = (4, 4)  And  C = (2, 8)  PC = √4+16=√20  d² = 20 Sequence and series

 Q. The number of common terms in  the progressions 4, 9, 14, 19, , up to 25th term and 3, 6, 9, 12, up to 37th term is:    ( JEE mains 2024) A. 9 B. 5 C. 7 D. 8 Show Answer Ans:- (c) 4, 9, 14, 19, ...., up to 25th term T₂5=4+(25-1)54+120=124 3, 6, 9, 12, up to 37th term T37=3+(37-1)3=3+108= 111 Common difference of Ist series d₁ = 5  Common difference of IInd series d₂ = 3  First common term = 9, and their common difference = 15 (LCM of d, and d₂)  then common terms are 9, 24, 39, 54, 69, 84, 99 Conic section

Chemistry Question Q. Sum of bond order of CO and NO + is _____. Enter your answer: Submit Correct Answer: (6) Solution: CO ⇒ C≡O : BO = 3 NO + ⇒ N≡O + : BO = 3 Sum of bond orders = 3 + 3 = 6

 Q. Among the following, total number of meta directing functional groups is - OCH3, NO2, CN, CH3-NHCOCH3, - COR, -OH, - COOH, -CI                                                             ( JEE mains 2024)  Show Answer Sol. (4)   -NO2,C=N, -COR, -COOH are meta directing. GOC PYQ

 Q. Among the given organic compounds, the total  number of aromatic compounds is                                                         ( JEE mains 2024)   Ans:- (3)    B.C and D are Aromatic Hydrocarbon

 Q. Four particles each of mass 1 kg are placed at four corners of a square of side 2 m. Moment of inertia of system about an axis perpendicular to its plane and passing through one of its vertex is ______ kgm2.                                                         ( JEE mains 2024) Show Answer Moment of Inertia of the System The moment of inertia (I) of four particles, each of mass 1 kg, placed at the four corners of a square of side 2 m, about an axis perpendicular to its plane and passing through one of its vertices is given by: \[ I = 16 \, \text{kg} \cdot \text{m}^2 \]

 Q. Given below are two statements: Statement I: Atoms are electrically neutral as they contain equal number of positive and negative charges. Statement II: Atoms of each element are stable and emit their characteristic spectrum. In the light of the above statements, choose the most appropriate answer from the options given below.                                                          (NEET-2024) 1. Both Statement I and Statement II are correct 2. Both Statement I and Statement II are incorrect 3. Statement I is correct but Statement II is incorrect 4. Statement I is incorrect but Statement II is correct Show Answer   Answer (3) Sol. Statement I is true as atoms are electrically neutral because they contain equal number of positive and negative charges. Statement II is wrong as atom of most of the elements are stable and emi...

 Q. All the letters of the word "GTWENTY" are written in all possible ways with or without meaning and these words are written as in a dictionary. The serial number of the word "GTWENTY" IS                                                         (jee mains 2024) Show Answer (553)  Words starting with E = 360  Words starting with GE = 60  Words starting with GN = 60  Words starting with GTE = 24  Words starting with GTN = 24  Words starting with GTT = 24  GTWENTY = 1  Total = 553 Physics                  Chemistry

 Q. An object is placed in a medium of refractive index 3. An electromagnetic wave of intensity 6 × 108 W/m² falls normally on the object and it is absorbed completely. The radiation pressure on the object would be (speed of light in free space = 3 × 108 m/s) :                                                         (jee mains 2024) 1. 36 Nm-² 2. 18 Nm-² 3. 6 Nm-² 4.  2 Nm-² Show Answer (3) -  Radiation pressure = I /V = Ιμ/C  =6×108×3/3×108  = 6 N/m²

 Q. A current of 200 µA deflects the coil of a moving coil galvanometer through 60°. The current to cause deflection through π/10 radian is:                                                          (JEE mains 2024) 1. 30 μΑ  2. 120 μΑ 3. 60 μΑ  4.  180 μΑ Show Answer (3)  i is directly proportional to θ i2/i1= θ2/θ1= 3/10  ⇒i2 = 60 μΑ

 Q. The atomic mass of (12C) is 12.000000 u and that of C13 is 13.003354 น. The required energy to remove a neutron from C¹³ , if mass of neutron is 1.008665 u, will be:                                                           (JEE mains 2024) 1. 62. 5 MeV  2. 6.25 MeV 3. 4.95 MeV  4.49.5 MeV Show Answer (4) 6C13+Energy----------> 6C12 1 +on  ∆m=(12.000000+ 1.008665) - 13.003354 =-0.00531 u ... Energy required = 0.00531 × 931.5 MeV = 4.95 MeV

 Q. Wheatstone bridge principle is used to measure the specific resistance (S1) of given wire, having length L, radius r. If X is the resistance of wire, 2 then specific resistance is: S₁ = X(πr²/ L) If the length of the wire gets doubled then the value of specific resistance will be:                                                        ( JEE mains 2024) 1.  S1/4 2. 2S1 3. S1/2  4.S1 Show Answer   (4) As specific resistance does not depends on dimension of wire so, it will not change.

 Q. Which structure of protein remains intact after coagulation of egg white on boiling?                                                         (JEE mains 2024) 1. Primary 2. Tertiary 3. Secondary 4.Quaternary Show Answer (1)  Boiling an egg causes denaturation of its protein resulting in loss of its quaternary, tertiary and secondary structures. Loading…

 Q. NaCl reacts with conc. H2SO4 and K2Cr2O7 to give reddish fumes (B), which react with NaOH to give yellow solution (C). (B) and (C) respectively are;                                                         (JEE mains 2024) 1. CrO2Cl2, Na2CrO4 2. Na2CrO4, CrO2Cl2 3. CrO2Cl2, KHSO4 4. CrO2Cl2, Na2Cr2O7 Show Answer NaCl + conc. H2SO4 + K2Cr2O7 →CrO2Cl2 + KHSO4 + NaHSO4 +H2O (B) Reddish brown  CrO2Cl2 + NaOH → Na2CrO4 + NaCl +H₂O                          (C) Yellow colour

 Q. The correct statement regarding nucleophilic substitution reaction in a chiral alkyl halide is;                                                         (JEE mains 2024) 1. Retention occurs in S₁l reaction and inversion occurs in SN2 reaction. 2. Racemisation occurs in Snl reaction and retention occurs in SN2 reaction. 3. Racemisation occurs in both SN1 and SN2 reactions. 4.Racemisation occurs in SN1 reaction and inversion occurs in SN2 reaction. Show Answer (4)  SN¹- Racemisation   SN² - Inversion More Questions