Chapter U5.2, Problem 5E

(a)

Interpretation Introduction

Interpretation: The substances that are the part of the system needs to be explained.

Concept Introduction: A system is any specified component of matter under analysis that is isolated from bounding surface of the rest of the universe. A system consists of one or more substances.

Answer to Problem 5E

  $\text{Ba}{\left(\text{OH}\right)}_{\text{2}}{\text{.8H}}_{\text{2}}\text{O}$ , ${\text{2NH}}_{\text{4}}{\text{NO}}_{\text{3}}$ , ${\text{NH}}_{\text{3}}$ , ${\text{H}}_{\text{2}}\text{O}$ and $\text{Ba}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}$ all are the part of the system.

Explanation of Solution

All substances that are involved in the reaction that means reactant and products are part of the system. The reaction is as follows:

  $\text{Ba}{\left(\text{OH}\right)}_{\text{2}}{\text{.8H}}_{\text{2}}\text{O}\left(\text{s}\right){\text{+2NH}}_{\text{4}}{\text{NO}}_{\text{3}}\left(\text{s}\right)\to {\text{2NH}}_{\text{3}}\left(\text{g}\right){\text{+10H}}_{\text{2}}\text{O}\left(\text{l}\right)\text{+Ba}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}\left(\text{aq}\right)$

Therefore, $\text{Ba}{\left(\text{OH}\right)}_{\text{2}}{\text{.8H}}_{\text{2}}\text{O}$ , ${\text{2NH}}_{\text{4}}{\text{NO}}_{\text{3}}$ , ${\text{NH}}_{\text{3}}$ , ${\text{H}}_{\text{2}}\text{O}$ and $\text{Ba}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}$ all are the part of the system.

(b)

Interpretation Introduction

Interpretation: Four objects that are the part of the surroundings needs to be explained.

Concept Introduction: The rest of the universe which might be in a position to exchange energy and matter with the system is termed as surrounding. In simple cases, surroundings generally imply water bath or air in which the matter which is system is examined.

Answer to Problem 5E

Beaker, air, room and table are the part of the surrounding.

Explanation of Solution

Anything which is not included in the system is referred to as surrounding. The other substances which are involved in the reaction is the part of the surrounding instead of reactants and products.

(c)

Interpretation Introduction

Interpretation: The temperature differences between ${\text{NH}}_{\text{4}}{\text{NO}}_{\text{3}}$ and $\text{Ba}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}$ needs to be explained.

Concept Introduction: Endothermic reactions consume energy from the surrounding in the form of heat. Exothermic reaction discharges energy into the surrounding from the system.

Answer to Problem 5E

  $\text{Ba}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}$ has lower temperature.

Explanation of Solution

Temperature is lower in $\text{Ba}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}$ than ${\text{NH}}_{\text{4}}{\text{NO}}_{\text{3}}$ . Because the water freezing outside the beaker shows that the temperature decreased after the reactant formation.

(d)

Interpretation Introduction

Interpretation: If the beaker of hydrated barium hydroxide and solid ammonium nitrate solution is touched, the observation needs to be explained.

Concept Introduction: Endothermic reactions consume energy from the surrounding in the form of heat. Exothermic reaction discharges energy into the surrounding from the system.

Answer to Problem 5E

The beaker will be cool because after reactant formation temperature decreased.

Explanation of Solution

Temperature is lower in $\text{Ba}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}$ than ${\text{NH}}_{\text{4}}{\text{NO}}_{\text{3}}$ . Because the water freezing outside the beaker shows that the temperature decreased after the reactant formation.

(e)

Interpretation Introduction

Interpretation: Whether the reaction between hydrated barium hydroxide and solid ammonium nitrate is endothermic or exothermic needs to be explained.

Concept Introduction: Endothermic reactions consume energy from the surrounding in the form of heat. Exothermic reaction discharges energy into the surrounding from the system.

Answer to Problem 5E

The reaction is endothermic.

Explanation of Solution

As heat is absorbed during the reaction so, after formation of the product temperature is decrease. It indicates the reaction is endothermic. Heat transfer accompanies all chemical changes. The heat is transferred either into the system or out of the system.

(f)

Interpretation Introduction

Interpretation: The heat transferred from the surroundings to the product of the reaction in the reaction between hydrated barium hydroxide and solid ammonium nitrate needs to be explained.

Concept Introduction: Endothermic reactions consume energy from the surrounding in the form of heat. Exothermic reaction discharges energy into the surrounding from the system.

Answer to Problem 5E

Endothermic reactions are chemical processes that result in the transfer of heat from the surroundings to the products of the reaction.

Explanation of Solution

As heat is absorbed during the reaction so, after formation of the product temperature is decrease. It indicates the reaction is endothermic. As the reaction is endothermic, so, heat is transferred from the surroundings to the product of the reaction.