(iv) Electrovalent compounds are soluble in polar solvents. APlusTopper.com provides ICSE Solutions for Class 10 Chemistry Chapter 2 Chemical Bonding for ICSE Board Examinations. (iii) An electrostatic force of attraction exist between the oppositely charged ions. Introduction to chemical bonding Chemical Bonding of Class 10. Electro-negativity of hydrogen = 2.1, Question 2: With the help of the figure Show HCl is-a polar molecule. How many electrons in the outer shell of a nitrogen atom are not involved in the formation of a nitrogen molecule ? The four carbon hydrogen bonds are directed towards the four corners of tetrahedron. Which are : (i) forms an anion (ii) forms a cation ? Answer: A co-ordinate bond is a union of one electrovalent and one covalent bond, the volatility of these compounds lies between that of covalent and ionic compounds. As a result hydrogen acquires partial positive charge and chlorine gets partial r negative charge. (ii) Give the molecular formula of the compound formed between E and G and state the type of chemical bond in this compound. This test is totally based on latest Chemistry textbook of ICSE Board. Question 5: Write important general characteristics of covalent compounds. All exercise questions are solved & explained by expert teacher and as per ICSE board guidelines. New Simplified Chemistry Class 10 ICSE Solutions – Chemical Bonding QUESTIONS 2006 Question 1. After the formation O→ H+ co-ordinate bond becomes identical to the two O—H covalent bonds. This charge is known as formal charge. Answer: When a molecule of hydrogen is formed from the atoms, energy is released (104 kcal/ mol). octet by sharing three of its valence shell electrons with three H-atoms. The arrow represents a co-ordinate bond. The force is termed as a chemical bonds. This test module contains five questions in fill in the blanks format. If sufficient number of water molecules strike a particular chloride ion in same fashion, then it can be pulled out of the crystal of sodium chloride to form free chloride ion. For example, in case of methane molecule, the four electron pairs shared between one carbon atom and four hydrogen atoms lie exactly in between one carbon atom and four hydrogen atoms and hence forms non-polar bonds. They can do so by losing, gaining or sharing of electrons. (b) Covalent bond. Answer: A molecule of HCl is a polar covalent, i.e., the electron pair shared between hydrogen and chlorine is far away from hydrogen than chlorine, with the result that hydrogen atom has a slight positive charge on it and the atom of chlorine has slight negative charge on it as, When hydrogen chloride is added to water, then water molecules bombard it from all directions. Answer: The cause of chemical combination between atoms of the various elements is their tendency to acquire nearest stable noble gas configuration of octet of electrons and duplet of electrons in case of hydrogen atoms in their outermost shells. 1Å = 10-10m and 1pm = 10-12 m. It is determined with the help of X-rays diffraction and other spectroscopic methods. Chemical Bonding ,Chemical Bonding and Molecular Structure - Get topics notes, Online test, Video lectures, Doubts and Solutions for CBSE Class 11-science on TopperLearning. Thus, there are large inter molecular spaces between the molecules. Question 18: (i) Which of the following is not a common characteristic of an electrovalent compound ? Answer: The formation of co-ordinate bond between two atoms to occur in the following two steps: E.g. Due to these strong forces of attraction, ionic compounds have high melting and boiling points and low volatility. Chemical Bonding and Bond Theories; Molecular Structures and Theories; Hydrogen Bonding; The attractive force which holds together the constituent particles (atoms or molecules) in chemical species is known as chemical bond. Thus their melting and boiling points are higher than covalent compounds and lower than ionic compounds. The acceptor atom must have an empty orbital to accept the lone pair of electrons. Back to Science for Kids The four carbon hydrogen tetrahedral structure. Question 12: Why ionic compounds are generally soluble in water, but insoluble in organic solvents ? Chemical bonding and molecular structure grade 11 1. Question 4: What are the salient features of electrovalency ? Answer: Because they are short of octet in their outermost shell. (iii) Electrovalent compounds have high density with high melting and boiling points. Answer: (1) Hydrogen chloride and hydrogen bromide. (ii) Covalent compounds have low melting or boiling points. (iii) The electronic configuration of nitrogen is 2, 5. In what kind of compound does this effect occur ? Thus, when electric potential is supplied, no ions migrate to opposite poles and hence no conduction of electric current takes place. (i) Classify the elements as metals and non-metals. Thus, the ionic compounds do not dissolve in them. Octet Rule. These ions occupy fixed position in the crystals and do not move when an electric field is applied. Answer: There is a strong force of attraction among the oppositely charged ions in the crystals of electrovalent compounds. Here you can get Class 11 Important Questions Chemistry based on NCERT Text book for Class XI.Chemistry Class 11 Important Questions are very helpful to score high marks in board exams. Give four properties of XY2. Answer: Formation of Hydronium ion, H3O+ : This ion formed by the combination of H2O molecule and H+ ion. Basically, in this chapter, students will learn the different bonds that exist between elements and how these bonds are important in the formation of a compound. Question 4: Why a molecule of hydrogen is more stable than the uncombined atoms ? Hence it is also called a semipolar bond or dotive bond. This makes the shell expand outward. They are reactive. Figures (b) and (c) show a sodium ion and a chloride ion has been pulled out of crystalline structure by water molecules. . We provide step by step Solutions for ICSE Chemistry Class 10 Solutions Pdf. State the following : (i) the outer electronic configuration of Y. Hence methane molecule is a non polar covalent compound. Answer: When an atom forms an anion, it gets one or more electrons (from another atom) in its outer shell. As the number of electrons in the outer shell is increased, the repulsion between them increases. Answer: The general characteristics of electrovalent compounds are: (i) Electrovalent compounds are mostly crystalline in nature. Question 10: Why electrovalent compounds in crystalline state do not conduct electricity ? Covalent bonds are a class of chemical bonds where valence electrons are shared between two atoms, typically two nonmetals. (iii) the bonding present in H2Y. (iii) has four electrons in its valence shell ? Tendency of atoms to attain stable configuration of eight electrons in their valence shell is cause of chemical combination. Ozone layer depletion is the thinning of the ozone layer that protects the earth from the harmful UV radiations. Negative ions —> Anions (Cl–, O2-, N3-, etc.) A-1, Acharya Nikatan, Mayur Vihar, Phase-1, Central Market, New Delhi-110091. Thus, hydrogen chloride can be termed as a polar covalent compound. (a) High melting point (b) Conducts electricity when motten (c) Consists of oppsitely charged ions (d) Ionises when dissolved in water (ii) What are the terms defined below: (a) A bond formed by a shared pair of electrons with both electrons coming from the same atom. Chapter 10: Chemical Bonding Ch 10 Page 1 . Answer: NH3 has one lone pair of electrons which is donates to hydrogen atom forming a co-ordinate bond. Formation of NH4+, Ammonium ion : This ion formed by the combination of NH3 molecule and H+ ion. together in different chemical species. So, it is smaller than the atom. Answer: Question 9: (i) Give one property of hydrogen chloride which agrees with it being a covalent compound. Question 14: Why is sodium ion (Na+) not reactive, but sodium metal is very reactive ? (ii) Explain why Carbon tetrachloride does not dissolve in water. Hence, it is a covalent compound. It donates its valence electron, the residual ion consists of a single proton. Answer: A covalent bond between two atoms is non-polar if the electrons involved in bond formation are equally shared between two atoms having similar electronegativities. Under normal conditions, which physical state will the compound QS exist in ? Question 11: Why do electrovalent compounds usually dissolve in water and molecular compounds dissolve in organic solvents ? Thus, a chemical bond is defined as a force that acts between two or more atoms to hold them together as a stable molecule. Question 13: Why molten NaCl conduct electricity but, CCl4 does not ? Question 11: Elements X, Y and Z have atomic number 6, 9 and 12 respectively. Pass out a copy of Chemical Bonds Lab to each student. This result in that atom A develops unit positive charge and atom B develops a unit negative charge. (ii) For each compound, give the formulae of the ions formed in aqueous solutions. Answer: The general characteristics of co-ordinate compounds are as follows: (i) Co-ordinate compounds are identical to normal covalent compounds. (b) A bond formed by a shared pair of electrons, each bonding atom contributing one electron to the pair. Answer: (i) Y has six electrons in its valence shell. Their is a great electrostatic force of attraction among these oppositely charged ions and as a result, ionic compounds form hard crystals. Valency: Valency is the main point on which chemical bonding depends. For example: A fluorine atom has seven valence electrons. Answer: The covalent molecules are held very weakly by van der Waal’s forces. Why ? Answer: (i) (d) (ii) (a) Co-ordinate bond. Answer: Electrovalent crystalline solids do not conduct electricity because the oppositely charged ions in them are held together by a strong electrostatic force of attraction. Chemical Bonding ICSE Class-10 Concise Chemistry Selina Solutions Chapter-2. Question 5: Draw dot diagrams to illustrate the structure of the molecules of: (i) Ammonia (ii) Carbon dioxide (iii) Methane (iv) Water Answer: Question 6: Give the electron dot structures of: (i) NaCl (ii) MgCl2 (iii) CaO (iv) Cl2 (v) H2O (iv) NH3 Answer: Question 7: Draw an electron dot diagram to show the structure of hydronium ion. In covalent compounds the polar charge on molecules is weak and does not have that much of attractive force on the molecules, organic solvents exert a greater polar attraction on covalent molecules and hence dissolve them. Marks and answers are given immediately. Answer: (i) Cation and anion (ii) There is a mutual sharing of electrons (iii) 2 (iv) Magnesium is oxidised and chlorine is reduced. (iii) Give the structure of hydroxyl ion. (ii) 2 (iii) Covalent (iv). Visit official Website CISCE for detail information about ICSE Board Class-10. Answer: Molten NaCl contains Na+ and Cl– ions, which are free to move, hence it conducts electricity. Answer: The cause of chemical combination between atoms of the various elements is their tendency to acquire nearest stable noble gas configuration of octet of electrons and duplet of electrons in case of hydrogen atoms in their outermost shells. Answer: The water molecules have high dielectric constant thus, water molecules easily break the ionic bonds between the ions. (v) The melting and boiling points are higher than covalent compounds and lower than ionic compounds. ; Assemble and test the electrical testing kit. For webquest or practice, print a copy of this quiz at the Chemistry: Chemical Bonding webquest print page. (iii) High lattice energy: The higher is the value of lattice energy, greater will be the electrostatic force of attraction between the oppositely charged ions and hence ionic compounds are formed with greater ease by release of energy. The electrons of lone pair on N-atom are donated to H+ ion and thus a N/EH co-ordinate bond is established in NH4+ ion. Choose […] Answer: Formation of hydronium ion: The type of bonding present in hydronium ion is co-ordinate bonding. State the type of bonding present in it. You can read more about how I set up the station labs here. Question 3: Explain how polar covalent compound HCl which is a bad conductor in pure and liquid state, ionises in water. Question 6: A cation is smaller than the atom from which it is formed. Question 22: Why the melting and boiling points of co-ordinate compounds are higher than covalent compounds and lower than ionic compounds ? Question 17: What is lone pair effect ? Draw the Lewis structures for the following molecules and ions: H2S, SiCl BeF2, C03, HCOOH. Question 20: Why hydrogen chloride can be termed as a polar covalent compound ? (v) Covalent compounds contain molecules and they undergo reactions slowly. These crystals are usually brittle. Answer: (i) It cannot explain the formation of molecules like BeF2, BF3 in which the central atom has less than 8 electrons in its valence shell. (iii) Name one compound which is covalent, but on dissolving in water conducts electricity ? Download Formulae Handbook For ICSE Class 9 and 10. Chemical Bonding and Molecular Structure-class XI 1. Each cation is surrounded by a definite number of anions and vice-versa. The following section consists of Chemistry Multiple Choice questions on Chemical Bonding For competitions and exams. Question 15: Which conditions are necessary for the formation of co-ordinate bond? (v) Electrovalent compounds exhibit isomorphism. We Provide Step by Step Answer of Exercise-2, with Intex -1, Intex-2 and Previous Year Questions of Exercise-2 Chemical Bonding ICSE Class-10 . Answer: Covalent compounds exists as gases, liquids or soft solids because they have weak forces of attraction between their molecules. In hydrogen chloride, chlorine being more electronegative attracts the shared pair of electrons towards itself. (iv) It does not conduct electric current in the solid state but conducts electric current in the molten or dissolved state. Answer: In covalent compounds, the molecules are held together by weak Van der Waal’s forces. (iv) the formula of the compound formed between calcium \(_{ 20 }^{ 40 }{ Ca }\) and Y. To be very honest, chemical bonding is the only chapter which is too easy to study. Give two limiations of this rule. Question 13: How is a co-ordinate bond formed? Further, since the number of protons remains the same as in the neutral atom, the nucleus attracts the increased number of electrons less strongly. Question 1: Why atoms combine with one another ? Bond forms to get the stability. Question 19: (i) Acids dissolve in water to produce positively charged ions. Chemical Bonding AndMolecular Structures 2. When the molecules of water bombard the sodium ion, such that the slightly negatively charged oxygen atom face sodium ion, then they exert an electrostatic pull on it. Question 7: In the formation of compound XY2, atorix X gives one electron to each Y atom. Question 20: Predict the type of bonding in the following molecules : (i) Oxygen (ii) Calcium oxide (iii) Water (iv) Methane (v) Ammonium ion (vi) Nitrogen (vii) Magnesium chloride (viii) Carbon dioxide (ix) Carbon tetra chloride (xi) Hydrogen cyanide (x) Hydrogen chloride Answer: (i) Covalent bond (ii) Ionic bond (iii) Covalent bond (iv) Covalent bond (v) Covalent bond (vi) Ionic bond (vii) Covalent bond (viii) Covalent bond (ix) Covalent bond (xi) Covalent and co-ordinate bonds (x) Covalent bond, Question 1: With the help of the figure, explain that methane molecule is a non-polar covalent compound ? This student-centered station lab is set up so students can begin to explore chemical bonding. (iv) Can Q and S, both be metals ? Question 18: Why most of the covalent compounds have density less than that of water ? (ii) In the formation of electrovalent compounds, electrons are transferred from one element to another. The formation of a covalent bond allows the nonmetals to obey the octet rule and thus become more stable. During the formation of H3O+, one pair of lone pair from O-atom is donated to the vacant ls-orbital of H+ ion and O — H co-ordinate bond is formed. Positive ions —> Cations (Na+, K+, Ca2+, etc.) Hence molecule of hydrogen is more stable than uncombined atoms. Any such aggregation in which atoms are held together and which is electrically neutral is called a molecule. Lewis symbols : The electrons present in the outermost energy level of an atoms and known as valence electrons. (iii) These compounds are soluble in non-polar solvents and insoluble in polar solvent. In liquids, the molecules are weakly attracted whereas in gases, these forces are almost non¬existent. 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