Author: Dr. Vikas Jasrotia

Case-Based Questions Chemistry Solid State                                 Passage – 1 Read the given passage and answer the questions that follow: A lattice can be generated by repeating a small portion called the unit cell. A crystal structure is made of atoms. In other words, the structure is an ordered array of atoms, ions or molecules. The different type of unit cells are Primitive Cubic Unit Cell, Body-centered Cubic Unit Cell, Face centered cubic unit cell. The primitive cubic unit cell has atoms only at its corner. Each atom…

Compounds and Properties of Nitrogen Dinitrogen Preparation of Dinitrogen: Dinitrogen is produced commercially by the liquefaction and fractional distillation of air. In the laboratory, dinitrogen is prepared by treating an aqueous solution of ammonium chloride with sodium nitrite. NH4CI(aq) + NaNO2(aq) → N2(g) + 2H2O(l) + NaCl (aq) It can also be obtained by the thermal decomposition of ammonium dichromate                                              (NH4)2Cr2O7  →Heat N2 + 4H2O + Cr2O3                                 …

Organic All Important Naming Reactions: Haloalkanes and Haloarenes 1) Finkelstein Reaction: This reaction used for the preparation of iodoalkanes from the corresponding chloroalkanes or bromoalkanes. 2) Fittig Reaction: In the reaction, haloarene is reacted with metallic sodium in the presence of anhydrous ether to form Diphenyl which is an aromatic hydrocarbon.                                                                                               …

Sample Question Paper Class 12 Chemistry 2020-2021 Class: XII   Chemistry  Session 2020-21  Time: 3 Hours                                                                                      Maximum Marks: 70 General Instructions:  Read the following instructions carefully. a) There are 33 questions in this question paper. All questions are compulsory. b) Section A: Q. No. 1 to 16 are objective type questions. Q. No. 1 and 2 are passage based…

General Properties of Group 15 p – Block elements The elements in which the last electron enters in the valence p-sub shell are called the p-block elements. They include elements from groups 13 to 18. Their general electronic configuration is ns2np1-6 where n = 2 (except He which has 1s2 configuration). They, includes metals, non-metals and metalloids.   Elements belonging to the s and p-blocks in the periodic table are called the representative elements or main group elements. Inert pair effect:  The tendency of ns2 electron pair to participate in a bond formation decreases with the increase in atomic…

Solved Questions Alcohols, Phenols and Ethers Solved Questions Alcohols, Phenols and Ethers: Que 1. What is the structure and IUPAC name of glycerol? Ans 1. IUPAC name is propane -1,2,3-triol. Que 2. Write the IUPAC name of the following compounds. Ans.    (A) 3-Ethyl-5-methylhexan-2,4-diol (B) 1-Methoxy-3-nitrocyclohexan Que 3. Write the IUPAC name of the compound given below Ans 3.    3-Methylpent-2-ene-1,2-diol Que 4. Name the factors responsible for the solubility of alcohols in water. Ans 4.   The solubility of alcohols and phenols in water is due to their ability to form hydrogen bonds with water molecules as shown. The solubility decreases with an…

Assertion Reason and Matchup Questions of Amines  Assertion Reason and Matchup Questions of Amines: Note: Match the items of Column I and Column II in the following questions  1. Match the reactions given in Column I with the statements given in Column Column I Column II (i) Ammonolysis (a) Amine with a lesser number of carbon atoms (ii) Gabriel phthalimide synthesis (b) Detection test for primary amines. (iii) Hoffmann Bromamide reaction (c) Reaction of phthalimide with KOH and R—X (iv) Carbylamine reaction (d) Reaction of alkyl halides with NH3 Ans 1. (i)-(d)  (ii)- (c) (iii)- (a) (iv)- (b) Explanation: (i)…

Solved Subjective and Objective Questions of Amines Solved Subjective and Objective Questions of Amines: Q1. Why Amines are basic in nature? Ans 1. The reaction of amines with mineral acids to form ammonium salts shows that these are basic in nature. Amines have an unshared pair of electrons on nitrogen atom due to which they behave as Lewis base. Q2. In Alkylamines and ammonia which is more basic and why? Ans 2. Due to the electron releasing nature of the alkyl group, it (R) pushes electrons towards nitrogen and thus makes the unshared electron pair more available for sharing with…

Intermolecular Forces and The Gas Laws Intermolecular Forces and The Gas Laws Introduction: Matter is anything that occupies space and has a definite mass. Matter mainly exists in three different states – solid, liquid, and gaseous states. Solids have a definite shape and definite volume. This is because in solids the particles are closely packed and so the intermolecular force of attraction is greater. Liquids have no definite shape but have a definite volume. In liquids, the intermolecular force of attraction is smaller than that in solids. So, the particles do not have a fixed position. Gases have no definite…

Solved Important Questions d & f Block Elements  Solved Important Questions d & f Block Elements: Que 1. Cu+ is not stable in an aqueous solution. Why? Ans 1. In an aqueous solution, Cu+ undergoes disproportionation to form a more stable Cu2+ ion. 2Cu+ (aq) → Cu2+ (aq) + Cu(s) The higher stability of Cu2+ in an aqueous solution may be attributed to its greater negative ∆hydH than that of Cu+. It compensates for the second ionization enthalpy of Cu involved in the formation of Cu2+ ions. Que 2. Which is a stronger reducing agent Cr2+ or Fe2+ and why?…