Author: Dr. Vikas Jasrotia

Class 11 Chemistry Case Study Questions – Chapter 1   Class 11 Chemistry Case Study Questions In these questions, a statement of Assertion followed by a statement of Reason is given. Choose the correct answer out of the following choices: (a) Assertion and Reason both are correct statements and Reason is the correct explanation for Assertion. (b) Assertion and Reason both are correct statements but Reason is not a correct explanation for Assertion. (c) Assertion is a correct statement but Reason is an incorrect statement. (d) Assertion is an incorrect statement but Reason is a correct statement. Read the passage…

Que. Write down the conclusion made from the α-scattering experiment and the defects of the Rutherford model of the atom. Ans. Conclusions of α-scattering experiment (a) Most of the space in the atom is empty as most of the α-particles passed undeflected. (b) A few positively charged α-particles were deflected. This shows that they are deflected by the small positively charged body in the atom. (c) The positively charged body called the nucleus is very small of radius 10–15 m as compared to the radius of the atom which is about 10–10 m. Defects: (i) Position of electrons: The exact…

Periodic Table NEET Questions PDF – Solved MCQs Periodic Table NEET Questions PDF Que 1. Identify the correct order of the size of the following: (a) Ca2+ < K+ < Ar < Cl– < S2– (b) Ar < Ca2+ < K+ < Cl– < S2– (c) Ca2+ < Ar < K+ < Cl– < S2– (d) Ca2+ < K+ < Ar < S2– < Cl– Ans 1. (a) Ca2+ < K+ < Ar < Cl– < S2– For isoelectronic species, the size of anion increases as the negative charge increases whereas the size of cation decreases with an increase in…

Structure of Atom NEET Questions (Solved MCQs) Structure of Atom NEET Questions Que 1. A packet of energy is called (a) Electron (b) Photon (c) Position (d) Proton Ans 1. (b) Photon Que 2. Among the following the false statement is (a) Compared to the mass of the lightest nucleus the mass of the electron is only about 1/1836. (b) The ratio of e/m, i.e., specific charge for a cathode ray is constant. (c) Among He2+, H+, He+, and H the species having the highest e/m ratio is He2+. (d) The e/m for positive rays in comparison to cathode rays is…

Slater’s Rules and Effective Nuclear Charge Consider an electron in one of the atomic orbitals of a multi-electron atom. Because of the repulsion by other electrons in the same or different orbitals, the nuclear charge felt by this electron will be less than the actual nuclear charge. This electron is said to be screened from the influence of the nuclear charge and the reduced charge felt by the electron is known as The Effective Nuclear Charge (Zeff). The intervening electrons screen the electrons present in the peripheral s, p, d or f orbitals of even the same principal shell to…

Normality and Molarity NORMALITY: Normality is one way to express the concentration of the solution It is the number of gram equivalents of a solute present in one litre of solution. w = Mass of solute in gram V = Volume of solution in ml E = Equivalent weight of solute The equivalent weight of Solute: It is the number of parts by weight of the substance that combines or displaces, directly or indirectly, 1.008 parts by mass of hydrogen or 8 parts by mass of oxygen, or 35.5 parts by mass of chlorine. It can be calculated as (i)…

Que: A compound made up of two elements A and B has A= 70 %, B = 30 %. Their relative number of moles in the compound are 1.25 and 1.88. calculate a. Atomic masses of the elements A and B b. Molecular formula of the compound, if its molecular mass is found to be 160. Ans. Relative no. of moles of an element = % of the element/Atomic mass Atomic mass = % of the element/Relative no. of moles = 70/1.25 = 56 Atomic mass of B = 30/1.88 = 16 Calculation of Empirical formula Element Relative no. of…

Que. Calcium carbonate reacts with aqueous HCl to give CaCl2 and CO2 according to the reaction, CaCO3(s) + 2 HCl(aq) → CaCl2(aq) + CO2(g) + H2O(l). What mass of CaCO3 is required to react completely with 25 mL of 0.75 M HCl? Ans. 0.75 M means 0.75 mol of HCl is present in 1 L of solution 1 Mol of HCl weighs = 1 + 35.5 = 36.5 g 0.75 mol of HCl weighs = 0.75 × 36.5 = 27.37 g ⸫ 27.37 g of HCl is present in 1000 ml (1 L) of solution 1000 ml of solution…

CBSE Sample Paper Class 10 Science (2022-23) Central Board of Secondary Education (CBSE) has released the Sample Papers 2023 for the Class 10 board examination. Sample papers are one of the best resources for learners during revision and preparation for the final board exam. The sample papers are now available on the official websites cbseacademic.nic.in and cbse.gov.in. By doing the practice of these sample papers, students can get a good idea and knowledge of the paper pattern and the way to write the answers. CBSE Sample Papers lay out the paper pattern, the kind of questions and the choices, etc.,…

CBSE Sample Paper Session 2022-23 Chemistry Central Board of Secondary Education, CBSE has publicized the CBSE Sample Papers 2023 for the Class 12 board examination. Sample papers or model papers are one of the best resources for learners during revision and preparation for the final board exam. The sample papers are now available on the official websites cbseacademic.nic.in and cbse.gov.in. By practicing these, students can get a good idea of the paper pattern. CBSE Sample Papers lay out the paper pattern, the kind of questions and the choices, etc., that would form the question papers of the CBSE Board Examinations…