Last Updated on December 1, 2024 by studentabc.xyz
Chemical Reactions And Equations Science Class 10 Selected Important Questions:-
OMR
Q:- Which of the following metals can replace copper from a solution of a copper sulphate ?
(a) Silver
(b) Gold
(c) Zinc
(d) Mercury
Ans :- (c) Zinc
Q:- The process of respiration is –
(a) Endothermic reaction
(b) Exothermic reaction
(c) Both a & b
(d) Precipitation reaction
Ans:- (b) Exothermic reaction
Q:- What happens when dilute hydrochloric acid is added to iron fillings ?
(a) Hydrogen gas and iron chloride are produced
(b) Chlorine gas and iron hydroxide are produced
(c) No reaction takes place
(d) Iron salt and water are produced
Ans:- (a) Hydrogen gas and iron chloride are produced
Q:- Fatty foods become rancid due to the process of
(a) reduction
(b) corrosion
(c) oxidation
(d) none of these
Ans:- (c) oxidation
Selected Qus & Ans :-
Q:- What does one mean by exothermic and endothermic reactions ? Give examples.
Ans:-Exothermic reactions release heat to the surroundings e.g.burning of wood & Endothermic reactions absorb heat from the surroundings e.g. melting of ice
Q:- What is balanced chemical equation ? Why should chemical equation be balanced ?
Ans:-A balanced chemical equation is one in which the number of atoms of each element is the same on both the reactant and product sides.
Balancing a chemical equation is important because it follows the law of conservation of mass,which states that matter cannot be created or destroyed in a chemical reaction.It ensures that the total mass of the reactants equals the total mass of the products.
Q:- What do you mean by Corrosion and Rancidity ? Explain with examples.
Ans:- Corrosion is the process where metals deteriorate due to a chemical reaction with their environment, usually involving oxygen and moisture.This leads to the formation of compounds like rust on iron.e.g,iron rusting when exposed to air and moisture.
Rancidity occurs when fats and oils react with oxygen,causing them to spoil and develop an unpleasant taste and odor.e.g,the bad smell of old cooking oil left exposed for a long time.
Q:- Name the gas which is used to prevent oxidation inside of a chips packets.
Ans:-The gas used to prevent oxidation inside chips packets is nitrogen.It helps displace oxygen and moisture, keeping the chips fresh and crunchy.
Q:- What are oxidising agents ?
Ans:-Oxidising agents are substances that can accept electrons in a chemical reaction,causing another substance to be oxidized.They often contain elements in high oxidation states and facilitate the transfer of oxygen or the removal of hydrogen.Examples include oxygen,chlorine and potassium permanganate.
Practice Set
MCQ/OMR
Q:- What happens when dilute hydrochloric acid is added to iron filings ?
(a) Hydrogen gas and iron chloride are produced.
(b) Chlorine gas and iron hydroxide are produced.
(c) No reaction takes place.
(d) Iron salt and water are produced.
Q:- Which of the following does not involve a chemical reactions ?
(a) Digestion of food
(b) Respiration
(c) Burning of candle
(d) Melting of candle.
Q:- Which of the following statements is true for an oxidizing agent ?
(a) It gives hydrogen
(b) It gives oxygen
(c) It takes oxygen
(d) None of the above
VSA
Q:- Why do we apply paint on iron articles ?
Q:- Write the thermite reaction.
Q:- What will happen if a solution sodium hydrocarbonate is heated ? Give the equation of the reaction involved.
Q:- What is substitution reaction ? Explain with example.
Q:- What do you mean by Corrosion and Rancidity ? Explain with examples.
What To Know
- – Which of the following metals can replace copper from a solution of a copper sulphate .
- -A balanced chemical equation is one in which the number of atoms of each element is the same on both the reactant and product sides.
- Balancing a chemical equation is important because it follows the law of conservation of mass,which states that matter cannot be created or destroyed in a chemical reaction.