SEBA Class 10 Science Important Chapter 1 Chemical Reaction and Equations

SEBA Class 10 Science Important Chapter 1 Chemical Reaction and Equations Solutions English Medium As Per SEBA New Syllabus to each chapter is provided in the list so that you can easily browse through different chapters SEBA Class 10 Science Additional Solutions in English and select need one. SEBA Class 10 General Science Additional Notes English Medium Download PDF. SEBA Important Solutions for Class 10 Science.

SEBA Class 10 Science Important Chapter 1 Chemical Reaction and Equations

Also, you can read the NCERT book online in these sections Solutions by Expert Teachers as per Central Board of Secondary Education (CBSE) Book guidelines. Assam SEBA Board Class 10 General Science Additional Question Answer are part of All Subject Solutions. Here we have given SEBA Class 10 Science Important Question Answer English Medium for All Chapters, You can practice these here.

Chemical Reaction and Equations

Chapter: 1

IMPORTANT QUESTION ANSWER

Q.1. What is a chemical equation? 

Ans: A chemical equation is the symbolic representation of a chemical reaction in the form of symbols and formulae, wherein the reactant entities are given on the left-hand side and the product entities on the right-hand side.

For example: NaOH + HCl ⟶ NaCl+H2O

Q.2. How do we came to know that a chemical reaction has taken place? 

Ans: The presence of any of the following changes helps us to determine that a chemical reaction has taken place.

(i) Formation of new substance(s) 

(ii) Change in state

(iii) Change in colour 

(iv) Change in temperature

(v) Formation of a precipitate 

(vi) Evolution of a gas

For example: if on mixing two substances a gas is evolved, then we can say that a chemical reaction has taken place.

Q.3. How magnesium oxide is formed? 

Ans: Magnesium oxide is formed due to the reaction between magnesium and oxygen present in the air. 

Q.4. When an unbalanced equation formed? 

Ans: If the number of atoms of each element are not same on the both sides then an unbalanced equation formed. 

Q.5. What is combination reactions? Give one example? 

Ans: Reactions in which two or more reactants combine to form one product are called Combination reactions. 

For example: CaO + H₂O  →  Ca(OH)₂

Q.6. Give two examples of exothermic reactions? 

Ans: Here are some of the examples of exothermic reactions:

• Burning of Sugar.
• Formation of Ion Pairs.

Q.7. What is thermal decomposition? Give two examples. 

Ans: Thermal decomposition is a chemical reaction where heat is a reactant. Since heat is a reactant, these reactions are endothermic meaning that the reaction requires thermal energy to break the chemical bonds in the molecule.

Example:          

Q.8. Why silver chloride turns grey in sunlight? 

Ans: Silver chloride turning grey in sunlight is an example of Decomposition Reaction. White silver chloride turns grey in sunlight. This is due to the decomposition of silver chloride into silver and chlorine by light. Silver bromide also behaves in the same way.

Q.9. Balance the following skeletal equations-

(i) KCIO₃ → KCI + O₂ 

(ii) CH₄ + O₂ → CO₂ + H₂O 

(iii) Nacl + H₂SO₄ → Na₂So₄ + HCI 

(iv) H₂S + O₂ → H₂O + S 

(v) H₂ + N₂ → NH₃ 

Ans. (i) 2KCIO₃ → 2KCI + 3O₂ 

(ii) CH₄ + 2O₂ → CO₂ + 2H₂O 

(iii) 2Nacl + H₂SO₄ → Na₂So₄ + 2HCI 

(iv) 2H₂S + O₂ → 2H₂O + 2S 

(v) 3H₂ + N₂ → 2NH₃ 

Q.10. What is the need to balance a chemical equation with respect to mass and change? 

Ans: The balancing of the chemical equation is done to satisfy the law of conservation of mass, i.e. “Total mass of all the products of the reaction in a chemical reaction is equal to the total mass of all the reactants”. The equation must be balanced with respect to charge because the electrons lost by atoms to form cations are equal to the electrons gained by other atoms to form anions. Thus, as the reaction mixture does not contain any free electrons, the total positive change should be equal to the total negative charge.