RBSE Class 9 Science Chapter 4 Chemical Bond and Chemical Equation Solutions can help students to understand all the concepts of the chapter thoroughly and gain good scores in the exams. It is also the most crucial resource that is used by students to revise the chapter well. Learning these solutions will help to comprehend the subject matter and master it thoroughly. Meanwhile, these questions from the RBSE Class 9 Solutions for Chapter 4 Science include all the highlights from the topics covered in the chapter. The chapterwise important topics and questions from the RBSE Class 9 Science help students to prepare most competently for the RBSE Class 9 exams. Meanwhile, in order to master the concepts taught in class, the students are advised to improve their performance by implementing strategic learning. Here, we have attempted to list out the collection of important questions from Chapter 4 of RBSE Class 9 Science Textbook. Solving these questions will provide enough practice for the students to score high marks. Students who have mastered the subject will be able to have a proper foundation of the subject before moving to higher classes and it will also help them to score high marks.
Rajasthan Board Class 9 Science Chapter 4- BYJU’S Important Questions & Answers
RBSE Class 9 Science Chapter 4 Objective Questions-Important Questions and Solutions
Q. 1. The symbol for sodium is____
Answer: (c) Na
Q.2. The formula for carbonate radical is
Answer: (b) CO32–
Q.3. The name of the bond present in sodium chloride is :
(a) Ionic bond
(b) Covalent bond
(c) Metallic bond
(d) Hydrogen bond
Answer: (a) Ionic bond
Q. 4. The element exhibiting variable valency is :
Answer: (d) Cu
Q. 5. The formula for calcium oxide is
Answer: (c) CaO
Q. 6. The generator of the modern system of symbols for elements was :
(b) John Dalton
(d) Neil Bohr
Answer: (a) Berzillius
Q.7. The molecule with covalent bond is :
Answer: (a) H2O
Q.8. Fe is the symbol for :
Answer: (a) Iron
Q. 9. What are radicals?
Answer: Ionic substances, acids and bases dissolve in water and dissociate into ions that take part as a unit in reactions. They are termed as radical.
Q. 10. Define ionic bond.
Answer: The force of electrostatic attraction that develops between the oppositely charged ions, also known as electro valent bond is ionic bond.
Q.11. Write the symbol and Latin name of Potassium.
Answer: Symbols for certain elements are obtained from their latin names. Since the Latin name of Potassium is Kallium, the symbol used for it is K.
Q.12. Define molecular formula.
Answer: A group of two or more atoms that are bound together by chemical bonds are known as Molecules. Meanwhile, a molecular formula is a combination of the symbols of elements that represent the molecule or a compound.
Q.13. Write the formula for calcium carbonate.
Answer: The formula for Calcium Carbonate is CaCO3.
Q.14. Write the formula of a tri valent acidic radical.
Answer: Phosphate is trivalent acidic radical with formula PO3– 4
Q.15. What are anions?
Answer: Negatively charged particles that are created by combining one or more electrons in the outermost valence shell of the gaseous atom of the isolated element are known as anions.
Q.16. What is valency?
Answer: The number of electrons that are shared or transferred by an atom in order to make up the octet in its outermost orbit is called combining capacity or valency. If the external shell has 8 electrons then it has a complete octet. Atoms of every element have a definite valency. Also, the number of bonds that can be formed by an atom as part of a compound is expressed by the valency of the element.
17. “The size of cation is smaller than the total size of the atoms that make it.” Explain.
Answer: Cation is normally smaller in size compared to its compliant atom because when an electron is removed from the outermost shell, the force of attraction between the nucleus and the electrons is increased, further reducing its size.
18. Explain variable valency with the help of an example.
Answer: Some elements may not have specific valency, instead might have more than one valency. This is known as variable valency. Given is the example of Copper. The element copper of symbol Cu has valency 1 and 2.
Q.19. What is a co-ordinate bond? Give an example.
Answer: A type of covalent bond in which the electron pair for the bond formation is provided by only one atom, while sharing is between both the atoms is known as co-ordinate bond. Ozone molecules are an example of co-ordinate bond.
Q.20. Explain the energy of ionization.
Answer: The amount of energy that is essential for an isolated gaseous atom to lose an electron in its ground state is known as the energy of ionization.
Q.21. Explain double and triple bonds with the help of examples.
Answer: When there is sharing of two pairs of electrons between the two atoms, a double bond is said to be formed. For example : This type of bonding occurs between oxygen atoms. At the same time, in case, three-three electrons from each atom are shared between the two atoms, a triple bond is formed. For example in nitrogen this type of bond is formed. Know more here at Single bond, double bond and triple bond.
RBSE Class 9 Science Chapter 4 Essay Type Questions-Important Questions and Solutions
Q.22. Differentiate between covalent and ionic bonds.
Answer: Chemical bonds can be a covalent or an ionic bond. Know more about the differences between covalent and ionic bonds here.
Q.23. Write the molecular formula of the following :
(i) Sodium carbonate
(ii) Zinc sulphide
(iii) Aluminium oxide
(iv) Ferric sulphate
(v) Barium chloride
(vi) Magnesium carbonate
Answer: (i) Sodium Carbonate – Na2CO3
(ii) Zinc Sulphide- ZnS
(iii) Aluminium Oxide- Al2O3
(iv) Ferric Sulphate- Fe2(SO4)3
,(v) Barium Chloride- BaCl2
(vi) Magnesium Carbonate – MgCO3
Q.24. Balance the following reactions :
(i) KClO3 ->KCl + O2
(ii) BaCl2 + AgNO3->AgCl + Ba (NO3)2
(iii) Mg + HCl-> MgCl2 + H2
(iv) NaOH + Cl2-> NaCl + NaOCl + H2O
Answer: (i) Given here is the unbalanced equation to start with KClO3 ->KCl + O2
,To balance the equation use 2 as a co-efficient before the equation.
I.e., 2KClO3 ->2KCl + O2
Here, you can see that while K and Cl have been balanced out on both sides, there are 6 oxygen atoms on the left. Hence, to make the oxygen atom on the right 6, you need to place a 3 in front of O2.
Hence, the balanced equation will be 2KClO3 ->2KCl + 3O2
(ii) Begin with BaCl2 + AgNO3->AgCl + Ba (NO3)2
The add co-efficient 2 to get balanced equation
i.e, BaCl2 + 2AgNO3->2AgCl + Ba (NO3)2
(iii) Equation Mg + HCl-> MgCl2 + H2
Then add 2 as a co-efficient before HCl to balance the equation
Hence, Mg + 2HCl-> MgCl2 + H2
(iv) For NaOH + Cl2-> NaCl + NaOCl + H2O
Hence, balanced equation is 2 NaOH + Cl2 = NaCl + NaOCl + H2O
RBSE Class 9 Science Chapter 4 Additional Important Questions and Solutions
Q.25. Simple arrow is replaced by ____ to represent reversible reaction.
Answer: (a) ⇌
Q.26 What sign is used when the reaction is exothermic?
- Positive sign
- Negative sign
- Arrow sign
- Equal sign
Answer: (a) Positive sign
Q.27 What is the latin name for sodium?
Answer: (d) Natrium
Q.28 Who was the first scientist to use a symbol to denote a definite amount i.e. an atom
of an element?
- John Dalton
- Ernest Rutherford
- J.J. Thompson
Answer: (b) John Dalton
Q.29 The number of electrons in the outermost shell of oxygen and fluorine is__
- 2 and 1
- 3 and 5
- 6 and 7
- 3 and 4
Answer: (c) 6 and 7
Q.30 Which is the compound having polyatomic ions?
- Hydrogen sulphide
- Calcium chloride
- Calcium oxide
- Barium sulphate
Answer: (d) Barium Sulphate
Q.31 Ionic compounds are soluble in polar solvents such as _____
- Methylene chloride
Answer: (b) Water
Q.32 Ionic compounds are _____
- Solid and brittle
- Soft and malleable
- Voluminous Gas
- Liquid smooth
Answer: (a) Solid and brittle
Q.33 Atoms are electically____
Answer: (a) Neutral
Q.34 Which of the following is made up of only one type of atoms?
- Simple radical
- Compound radical
- Acidic radical
- Basic radical
Answer: (a) Simple radical
Q.35 Example for a monatomic uni valent cation.
- Sodium Na+
- Zinc Zn2+
- Iodide I–
- Carbonate CO3
Answer: (a) Sodium Na+
Q.36 What is a compound radical?
Answer: A compound radical is a group of two or more types of atoms having a definite charge.
Q.37 What is basic radical and acidic radical?
Answer: Basic radical is metallic cation or positively charged radicals also known as ash – radical because they are obtained from metallic ashes. Meanwhile, non-metallic anions
and negatively charged radicals are known as Acidic radical.
Q.38 Who formulated the “Octet Rule?” What is it?
Answer: In 1916 Corcel-Lewis formulated the “Octet rule.” As per the rule, “There is transfer or sharing of electrons between two atoms to complete the octet in the outermost (valence) shell of atom and thus the two atoms combine with each other.”
Q.39 How is the formula for poly-atomic ions written?
Answer: The formula for poly-atomic ions are written within the brackets and their number is subscripted outside. The example is given here: Al2(SO4) 3.
Q.40 What is a chemical bond?
Answer: Chemical bond is a force of attraction existing between the component particles (ions,
atoms etc.) of a molecule that binds them together.
Q. 41 Draw a structure of the Sodium Chloride?
Q.42 What are the prerequisite conditions for formation of coordinate bond?
Answer: Given below are the prerequisites for the formation of coordinate bond:
1. One atom should have at least one lonely electron pair after the completion of its octet.
2. The other atom must have a deficiency of at least one electron pair.
Studying from the textbooks and revising all the concepts help students to ace the subject. They can also rely on these RBSE Class 9 Science Solutions to understand all the topics completely. Other best resources that the students can find to prepare most competently for the exam are the RBSE textbooks and sample papers.
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