Question

½H2(g) + ½I2(g) → HI(g), ΔH = +6.2 kcal/mole 21.0 kcal/mole + C(s) + 2S(s) → CS2(l) What type of reaction is represented by the previous two examples?

Answer 1

Answer:

Exothermic Reaction are those reaction, in which energy is released while in endothermic reaction are those, in which energy is absorbed.

Explanation:

First Reaction:

As in this reaction, energy is released

½H2(g) + ½I2(g) → HI(g), ΔH = +6.2 kcal/mole

so it is exothermic reaction

Second reaction:

As in this reaction, energy is absorbed

21.0 kcal/mole + C(s) + 2S(s) → CS2(l)

so it is endothermic reactions.

Answer 2

Answer:

Both the reactions are example of the endothermic reaction.

Explanation:

Endothermic reaction is a type of of chemical reaction in which energy is absorbed from the surrounding. The temperature of the surrounding decreases. The enthalpy of reaction is always positive $\Delta H_{rxn}>0$

$\frac{1}{2}H_2(g) + \frac{1}{2}I_2(g)\rightarrow HI(g), \Delta H = +6.2 kcal/mol$

The above reaction is an example of endothermic reaction.

$21.0 kcal/mol + C(s) + 2S(s) \rightarrow CS_2(l)$

This reaction is also an endothermic reaction in which energy is being added on the reactant side which indicates that energy is absorbed during the reaction.

Exothermic reaction is a type of of chemical reaction in which energy is released into the surrounding. The temperature of the surrounding increases..The enthalpy of reaction is always negative$\Delta H_{rxn}$