Manju Kaushik Q.1. Number of protons, neutrons and electrons in the element 89X231 is(a) 89, 89, 242 (b) 89, 142, 89(c) 89, 71, 89 (d) 89, 231, 89 Answer (b) Number of p = number of e– = 89 and neutrons 231 – 89 = 142. Q.2. Atoms with same mass number but different atomic numbers are … Read more
Q.1. Which one of the following sets of compounds correctly illustrate the law of reciprocal proportions?(a) P2O3, PH3, H2O (b) P2O5, PH3, H2O(c) N2O5, NH3, H2O (d) N2O, NH3, H2O Answer (a) In law of reciprocal proportions, the two elements combining with the third element, must combine with each other in the same ratio or … Read more
Very Short Answer Type Questions Page no: 220 1. Name the element whose one of the allotropic forms is buckminsterfullerene. Solution: Carbon is the element whose one of the allotropic forms is buckminsterfullerene. 2. What are the two properties of carbon which lead to the formation of a large number of carbon compounds? Solution: Catenation (Self … Read more
Very Short Answer Type Questions Page no: 66 1. What colour do the following indicators turn when added to a … Read more
NCERT Solutions For Class 12 Chemistry Chapter 3 Electrochemistry Here we are providing NCERT solutions for Class 12 Chemistry Chapter 3 Electrochemistry. NCERT TEXTBOOK QUESTIONS SOLVED 3.1. How would you determine the standard electrode potential of the system Mg2+1 Mg?Ans: A cell will be set up consisting of Mg/MgSO4 (1 M) as one electrode and standard hydrogen electrode … Read more
NCERT TEXTBOOK QUESTIONS SOLVED 1.1.Why are solids rigid?Ans: The constituent particles in solids have fixed positions and can oscillate about their mean positions. Hence, they are rigid. 1.2.Why do solids have a definite volume?Ans: The constituent particles of a solid have fixed positions and are not free to move about, i.e., they possess rigidity. That is why … Read more
HALOALKANESAlkyl halides : General formula is RX, where R = alkyl group. Classification : General methods of preparation :≫ From alcohols : Alkyl halides can be prepared from alcohols in a number of ways : – Action of hydrogen halides : • Order of reactivity of halogen acids towards the above reaction is :HI > … Read more
Prepare better for your exams with our standard Class 12 Chemistry NCERT solution.
Solution : A perfectly homogeneous mixture of two or more components is called solution. Solute : The component which is present in lesser amount or whose physical state is changed during the formation of solution is called solute. Solvent : The component which is present in larger amount and determines the physical state of the … Read more
1. Zinc, cadmium and mercury are not considered as transition metals. Why? Ans. Zinc, cadmium and mercury have fully filled configuration. Therefore they are not considered as transition metal. 2. Write the general configuration of d- block elements. Ans. General electronic configuration of d- block elements is. 3. What are the factors that decide the ionization potential? Ans.The … Read more
Very Short Answer Type Questions Page no: 131 1. Name one metal and one non-metal which exist in liquid state at room temperature. Solution: Mercury is the metal and bromine is the non metal which exist ion liquid state at room temperature 2. Why are metals called electropositive elements whereas non-metals are called electronegative elements? … Read more
1. The non-metal which is liquid at room temperature is:a) Mercuryb) Brominec) Carbond) Helium Answer (b)BromineExplanation: Bromine is the only non-metal which exists as a liquid at room temperature. 2. The number of protons in an atom of an element A is 19 then, the number of electron in its ion A+ is:a) 18b) 19c) 20d) 21 Answer … Read more
1. Write the elements of group 15? Ans. The elements of group 15 are Nitrogen (N), Phosphorous (P) , Arsenic (As) , Antimony (Sb) and Bismuth (Bi). 2. Write chemical name & formulae of a) Chile saltpetre b) Indian saltpetre Ans. (a) Chile saltpetre – Sodium nitrate – (b) Indian saltpetre – Potasium nitrate – 3. … Read more
The text book of Lakhmir Singh And Manjit Kaur for Class 10 Biology gives the students a detailed picture about each and every chapter. This is the best book for your class 10 science preparation. We are providing you the detailed solutions for chapter 1 Life processes for free. Don’t forget to check out the links for other chapters. … Read more
1. Calculate the volume of water which could be added to 20 ml of 0.65 m HCl to dilute the solution to 0.2 m? Ans.For dilution – Vol of water to be added to 20 ml = = 65ml – 20ml = 45 ml. 2. A solution is prepared by dissolving 11g glucose in water at. What … Read more
MCQ Questions for Class 10 Science Chapter 2 Acids, Bases and Salts CBSE Class 10 SCIENCE Question Type MCQ No. of Questions 85 Useful for Class 10 Studying Students Class 10 Science Chapter 2 Acids, Bases and Salts MCQs with Answers Q.1. Which one of the following is acidic?(a) Lemon juice (b) Tomatoes (c) Milk (d) All Answer (d)All … Read more
Q.1. Magnesium ribbon is rubbed before burning because it has a coating of(a) basic magnesium carbonate(b) basic magnesium oxide(c) basic magnesium sulphide(d) basic magnesium chloride Answer Answer: a Q.2. The chemical formula of lead sulphate is (a) Pb2SO4(b) Pb(SO4)2(c) PbSO4(d) Pb2(SO4)3 Answer Answer: c Q.3. When green coloured ferrous sulphate crystals are heated, the colour of the crystal changes because(a) it … Read more
1. What is the shape of Iron pentacarbonyl? Ans. Geomectry = Trigonal bipyramidal/span> 2. What do you understand by stability of a complex and instability constant of coordination compounds? Ans. The stability of a complex in solution is the degree of association between the two species involved in the state of equilibrium. The instability constant is … Read more
1. Amoeba shows following kind of nutrition(a) autotrophic(b) holozoic(c) saprotrophic(d) parasitic Answer (b)Holozoic 2. The process by which blood is cleared of metabolic wastes in case of kidney failure is called(a) artificial kidney(b) dialysis(c) transplantation(d) filtration Answer (b)Dialysis 3. Woody plants carry gaseous exchange through(a) root hair(b) stem hair(c) Lenticels(d) epidermal cells. Answer (c)Lenticels 4. … Read more
1. What do you mean by the term –Adsorption ? Ans. The accumulation of molecular species at the surface rather than in bulk of a solid liquid is termed as Adsorption. 2. Explain the terms – Adsorbate and Adsorbent with examples Ans. The molecular species which get concentrated or accumulated at the surface are adsorbate eg. etc. … Read more
1. Is rate of reaction always constant? Ans. No. rate of a reaction is not always constant. It depends on many factors such as concentration, temperature etc. 2. Can order of reaction be zero? Give example. Ans. Yes, decomposition of ammonia on a hot platinum surface is a zero order of reaction at high pressure. 3. What … Read more
1. Can you store AgCl solution in Zinc pot? Ans. No. We can’t store AgCl solution in Zinc pot because standard electrode potential of Zinc is less than silver. 2. Define the term – standard electrode potential? Ans. When the concentration of all the species involved in a half-cell is unity, then the electrode potential is called … Read more
1. Define the term –solubility? Ans. The maximum amount of a substance that can be dissolved in a specified amount of solvent is called its solubility. 2. What is the effect of pressure on solubility of a gas? Ans. The solubility of a gas increases with increases of pressure. 3. State Henry’s Law. Ans. Henry’s Law states that … Read more
1. Give one use of Formalin. Ans. Formalin is used as a disinfectant, preservative for biological specimens and in leather industry. 2. What is the chemical name of Tollen’s reagent and Fehling’s solution. Ans. Tollen’s reagent = Ammoniacal Silver Nitrate Fehlings solution = Sodium Potassium Tartarate. 3. Write the structure of alkenes that on ozonolysis will … Read more
1. Write IUPAC names of :- i. Ans. 5 – Methyloctan-3-ol ii. Ans. 1-Chloro propan-2-ol iii. Ans. Pentan – 1,3,4 – triol iv. Ans. 2 – Methylpropan -2-ol v. Ans. 1,3 – Dibromo – 4- chloro – 2- butanol vi. Ans. 5 – Chloro – 4 – ethyl – 5- methyl hexanol. vii. Ans. 2 – Phenyl ethanol viii. Ans. 2- Methyl phenol. … Read more
1. Give IUPAC names of following compounds (i). (ii). (iii). (iv). (v). (vi). (vii). (viii). (ix). (x). Ans. (i). 1, 3- Dibromobutane (ii). 1- Cholopropan-2-ol(iii). 2, 3 – Dibromo-1-chloro-3-methylpentane(iv). 2-Choloro-3-ethyl-2-methyl pentane(v). 1-Chloro-2-phenylethane(vi). 1-Chloro-1-phenyl ethane(vii). 1, 2, 3, 4, 5, 6- hexachlorocyclohexane(viii). 2, 2- Dihexyl 1, 1, 1-Trichloro ethane(ix). 4, 4-dibromobiphenyl(x). 1, 3-Dibromo -3- methyl … Read more
CBSE Class 10 Science Chapter 6 Life Processes Unsolved MCQ Q.1. Tick the correct statement.(a) Arteries carry blood away from the heart while veins carry blood towards heart.(b) Veins carry blood away from the heart while arteries carry blood towards heart.(c) Both of them carry blood in the same direction.(d) Either of them can carry … Read more
CBSE Class 9 Science Chapter 5 Fundamental Unit of Life: Cell NCERT Solution Main topics covered in this part of CBSE Class 9 Science, The Fundamental Unit of Life: Study Notes, are: Definition of Cell Shape and Size of Cell Types of Cell Structure of Cell Cell Organelles Difference Between Animal Cell and Plant Cell … Read more
