Chapter U4.72, Problem 4E

(a)

Interpretation Introduction

Interpretation:

The balancing of given chemical equation has to be done.

Concept Introduction :

Balancing of chemical equation is important to obey the law of conservation of mass.

Answer to Problem 4E

The balanced chemical equation for given reaction is shown below.

  $\text{2K}\left(s\right)+{\text{I}}_2\left(s\right)\to 2\text{KI}\left(s\right)$

Explanation of Solution

The given unbalanced chemical equation is shown below.

  $\text{K}\left(s\right)+{\text{I}}_2\left(s\right)\to \text{KI}\left(s\right)$

A coefficient 2 is used and $\text{K}$ at left hand side and $\text{KI}$ at right hand side is multiplied with it.

  $\text{2K}\left(s\right)+{\text{I}}_2\left(s\right)\to 2\text{KI}\left(s\right)$

The number of potassium and iodine atoms are two on both the sides of the equation. Hence, the above equation is a balanced chemical equation.

(b)

Interpretation Introduction

Interpretation:

The balancing of given chemical equation has to be done.

Concept Introduction :

Balancing of chemical equation is important to obey the law of conservation of mass.

Answer to Problem 4E

The balanced chemical equation for given reaction is shown below.

  $\text{Mg}\left(s\right)+{\text{Br}}_2\left(l\right)\to {\text{MgBr}}_{\text{2}}\left(s\right)$

Explanation of Solution

The given chemical equation is shown below.

  $\text{Mg}\left(s\right)+{\text{Br}}_2\left(l\right)\to {\text{MgBr}}_{\text{2}}\left(s\right)$

The number of magnesium and bromine atoms is one and two respectively on both the sides of the equation. Hence, the above equation is a balanced chemical equation.

(c)

Interpretation Introduction

Interpretation:

The balancing of given chemical equation has to be done.

Concept Introduction :

Balancing of chemical equation is important to obey the law of conservation of mass.

Answer to Problem 4E

The balanced chemical equation for given reaction is shown below.

  $\text{KBr}\left(aq\right)+{\text{AgNO}}_{\text{3}}\left(aq\right)\to {\text{KNO}}_{\text{3}}\left(aq\right)+\text{AgBr}\left(s\right)$

Explanation of Solution

The given chemical equation is shown below.

  $\text{KBr}\left(aq\right)+{\text{AgNO}}_{\text{3}}\left(aq\right)\to {\text{KNO}}_{\text{3}}\left(aq\right)+\text{AgBr}\left(s\right)$

The number of potassium atom is one on both the sides of the equation. The number of bromine atom is one on both the sides of the equation. The number of silver atoms is one at the left hand side as well as at the right hand side of the equation. The number of nitrogen atoms is also one on both the sides. The number of oxygen atom is three at both the sides of the equation. Hence, above equation is balanced.

(d)

Interpretation Introduction

Interpretation:

The balancing of given chemical equation has to be done.

Concept Introduction :

Balancing of chemical equation is important to obey the law of conservation of mass.

Answer to Problem 4E

The balanced chemical equation for given reaction is shown below.

  ${\text{2KClO}}_{\text{3}}\left(s\right)\to 2\text{KCl}\left(s\right)+3{\text{O}}_{\text{2}}\left(g\right)$

Explanation of Solution

The given chemical equation is shown below.

  ${\text{KClO}}_{\text{3}}\left(s\right)\to \text{KCl}\left(s\right)+{\text{O}}_{\text{2}}\left(g\right)$

A coefficient of 2 is multiplied with ${\text{KClO}}_{\text{3}}$ and $\text{KCl}$ and 3 with ${\text{O}}_{\text{2}}$ as shown below.

  ${\text{2KClO}}_{\text{3}}\left(s\right)\to 2\text{KCl}\left(s\right)+3{\text{O}}_{\text{2}}\left(g\right)$

The number of potassium atom is two on both the sides of the equation. The number of chlorine atom is two on both the sides of the equation. The number of oxygen atom is six at both the sides of the equation. Hence, above equation is balanced.

(e)

Interpretation Introduction

Interpretation:

The balancing of given chemical equation has to be done.

Concept Introduction :

Balancing of chemical equation is important to obey the law of conservation of mass.

Answer to Problem 4E

The balanced chemical equation for given reaction is shown below.

  ${\text{2C}}_{\text{2}}{\text{H}}_{\text{6}}\left(g\right)+7{\text{O}}_2\left(g\right)\to 4{\text{CO}}_2\left(g\right)+6{\text{H}}_{\text{2}}\text{O}\left(l\right)$

Explanation of Solution

The given chemical equation is shown below.

  ${\text{C}}_{\text{2}}{\text{H}}_{\text{6}}\left(g\right)+{\text{O}}_2\left(g\right)\to {\text{CO}}_2\left(g\right)+{\text{H}}_{\text{2}}\text{O}\left(l\right)$

Multiply ethane with a coefficient of 2, oxygen with a coefficient of 7, carbon dioxide with a coefficient of 4 and water with a coefficient of 6 as shown below.

  ${\text{2C}}_{\text{2}}{\text{H}}_{\text{6}}\left(g\right)+7{\text{O}}_2\left(g\right)\to 4{\text{CO}}_2\left(g\right)+6{\text{H}}_{\text{2}}\text{O}\left(l\right)$

The number of carbon atoms is four at both the sides of the equation. The number of hydrogen is twelve at both the sides. The number of oxygen atoms fourteen at the left hand side as well as at the right hand side of the equation. Hence, the equation is balanced chemical equation.

(f)

Interpretation Introduction

Interpretation:

The balancing of given chemical equation has to be done.

Concept Introduction :

Balancing of chemical equation is important to obey the law of conservation of mass.

Answer to Problem 4E

The balanced chemical equation for given reaction is shown below.

  $\text{4Al}\left(s\right)+3{\text{O}}_{\text{2}}\left(g\right)\to 2{\text{Al}}_{\text{2}}{\text{O}}_{\text{3}}\left(s\right)$

Explanation of Solution

The given chemical equation is shown below.

  $\text{Al}\left(s\right)+{\text{O}}_{\text{2}}\left(g\right)\to {\text{Al}}_{\text{2}}{\text{O}}_{\text{3}}\left(s\right)$

A coefficient of 4 is multiplied with aluminum, 3 with oxygen and 2 with aluminum oxide as shown below.

  $\text{4Al}\left(s\right)+3{\text{O}}_{\text{2}}\left(g\right)\to 2{\text{Al}}_{\text{2}}{\text{O}}_{\text{3}}\left(s\right)$

The number of aluminum atom is four on both the sides of the equation. The number of oxygen atom is six at both the sides of the equation. Hence, above equation is balanced.

(g)

Interpretation Introduction

Interpretation:

The balancing of given chemical equation has to be done.

Concept Introduction :

Balancing of chemical equation is important to obey the law of conservation of mass.

Answer to Problem 4E

The balanced chemical equation for given reaction is shown below.

  ${\text{P}}_{\text{4}}\left(s\right)+6{\text{H}}_{\text{2}}\left(g\right)\to 4{\text{PH}}_{\text{3}}\left(g\right)$

Explanation of Solution

The given chemical equation is shown below.

  ${\text{P}}_{\text{4}}\left(s\right)+{\text{H}}_{\text{2}}\left(g\right)\to {\text{PH}}_{\text{3}}\left(g\right)$

A coefficient of 4 is multiplied with ${\text{PH}}_{\text{3}}$ , 6 with hydrogen as shown below.

  ${\text{P}}_{\text{4}}\left(s\right)+6{\text{H}}_{\text{2}}\left(g\right)\to 4{\text{PH}}_{\text{3}}\left(g\right)$

The number of phosphorus atom is four on both the sides of the equation. The number of hydrogen atom is twelve at both the sides of the equation. Hence, above equation is balanced.