Question

The reaction 4al (s) 3o2 (

g. → 2al2o3 (s) δh° = -3351 kj is ________, and therefore heat is ________ by the reaction.

Answer 1

Answer: The reaction is exothermic and therefore the heat is released by the reaction.

Step-by-step explanation:

There are 2 types of reaction based on the heat of the reaction:

• Exothermic reactions are defined as the reactions in which energy is released in the form of heat. The enthalpy change
  `(\Delta H^o)` of the reaction comes out to be negative for this kind of reaction.
• Endothermic reactions are defined as the reactions in which energy is absorbed in the form of heat. The enthalpy change
  `(\Delta H^o)` of the reaction comes out to be positive for this kind of reaction.

For the given chemical reaction:

`4Al(s)+3O_2(g)\rightarrow 2Al_2O_3(s);\Delta H^o=-3351kJ`

As, the enthalpy change of the reaction is negative. The reaction is considered as an exothermic reaction.

Hence, the reaction is exothermic and therefore the heat is released by the reaction.