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प्रश्न
Why is respiration considered an exothermic reaction? Explain.
Explain why respiration is considered as an exothermic reaction. Give the chemical equation for this reaction.
उत्तर १
Respiration is considered as an exothermic reaction because, in respiration, the oxidation of glucose takes place, which produces large amount of heat energy.
\[\ce{C6H12O6(aq) + 6O2(g) -> 6CO2(g) + 6H2O(l) + energy}\]
उत्तर २
We get this energy from the food we eat. During digestion, food is broken down into simpler substances. For example, rice, potatoes and bread contain carbohydrates. These carbohydrates are broken down to form glucose. This glucose combines with oxygen in the cells of our body and provides energy. The special name of this reaction is respiration. Thus, respiration is an exothermic process because energy is produced during this process.
\[\ce{C6H12O6(aq) + 6O2(aq) -> 6CO2(aq) + 6H2O(l) + energy}\]
संबंधित प्रश्न
What type of chemical reaction take place when ammonia and hydrogen chloride are mixed?
Define a combination reaction.
When hydrogen burns in oxygen, water is formed and when water is electrolysed, then hydrogen and oxygen are produced. What type of reaction takes place:
(a) in the first case?
(b) in the second case
Define a chemical reaction.
Fill in the blank
A reaction in which two or more substances combine to form a single substance is called a ............ reaction.
Classify the following reaction as combination, decomposition, displacement, precipitation and neutralization. Also balance the equation.
\[\ce{CaCO3_{(s)} ->[heat]CaO_{(s)} + CO2_{(g)}}\]
What are chemical combination or synthesis reactions ? Chemical combination or synthesis:
What effect does an increase in concentration of H+ (aq.) in a solution have on the pH of solution?
(a) What is double displacement reaction? Explain with an example.
(b) A small amount of quick lime is added to water in a beaker.
(i) Name and define the type of reaction that has taken place.
(ii) Write balanced chemical equation for the above reaction and the chemical name of the product formed.
(iii) List two main observations of this reaction.
Calcium oxide reacts vigorously with water to produce slaked lime.
\[\ce{CaO{(s)} + H2O(l) -> Ca(OH)2(aq)}\]
This reaction can be classified as:
(A) Combination reaction
(B) Exothermic reaction
(C) Endothermic reaction
(D) Oxidation reaction
Classify the following reaction into different type:
CaO(s) + H2O(l) → Ca(OH)2(aq)
Give a balanced equation for –
A direct combination reaction involving two elements, one of which is a non-metal
Complete the statement by filling in the blank with the correct word:
Direct combination reaction of phosphorus pentoxide with water gives _______.
Which changes occur during chemical changes?
H2(g) + Cl29(g) → 2HCl(g) is a ______
Which of the following are exothermic processes?
(i) Reaction of water with quick lime
(ii) Dilution of an acid
(iii) Evaporation of water
(iv) Sublimation of camphor (crystals)
Combustion reactions are always ____________.
The Salt Story
From: The New Indian Express 9 March 2021
The salt pans in Marakkanam, a port town about 120 km from Chennai are the third largest producer of salt in Tamil Nadu. Separation of salt from water is a laborious process and the salt obtained is used as raw materials for manufacture of various sodium compounds.
One such compound is Sodium hydrogen carbonate, used in baking, as an antacid and in soda acid fire extinguishers.
The table shows the mass of various compounds obtained when 1litre of sea water is evaporated.
| COMPOUND | FORMULA | MASS OF SOLID PRESENT /g |
| Sodium Chloride | NaCl | 28.0 |
| Magnesium Chloride | MgCl2 | 8.0 |
| Magnesium Sulphate | MgSO4 | 6.0 |
| Calcium Sulphate | CaSO4 | 2.0 |
| Calcium Carbonate | CaCO3 | 1.0 |
| TOTAL AMOUNT OF SALT OBTAINED | 45.0 | |
Which compound in the table reacts with acids to release carbon dioxide?
Balance the following chemical equation and identify the type of chemical reaction.
`"Na"("s") + "S"("s") overset("(Fuse)")(->) "Na"_2"S"("s")`
Balance the following chemical equation and identify the type of chemical reaction.
`"CaO"("s") + "SiO"_2("s") -> "CaSio"_3("s")`
