<h2>Which of the following reactions is endothermic-</h2><h2>½N2(g) + O2(g) + 8.1 kcal → NO2(g)</h2>
Explanation:
Chemical reaction
When two or more substances react and form some new substance it is called as chemical reaction .
A + B --> C + D
(reactants ) (products )
When ever chemical reaction occurs following changes can occur :
- Change in colour
- Ppt formation
- energy changes
- Change in state
- Evolution of gas etc
On the basis of energy changes : reactions are of two types :
Endothermic
Exothermic
Endothermic reaction
A reaction in which heat is absorbed .
Example :½N2(g) + O2(g) + 8.1 kcal → NO2(g)
Exothermic reaction
A reaction in which heat is released .
For example : H2(g) + ½O2(g) → H2O(g), ΔH = -57.82 kcal
½N2(g) + 3/2H2(g) → NH3(g) + 11.0 kcal
C(diamond) + O2(g) → CO2, ΔH = -94.50 kcal
