Chapter 9, Problem 3A

(a)

Interpretation Introduction

Interpretation:

The meaning of the equation needs to be stated in the terms of numbers of individual molecules and in the terms of moles of molecules.

  $NO{\left(g\right)}^{}+O_2\left(g\right)\to N{O}_2\left(g\right)$

Concept Introduction:

The balanced equation shows that different reactants react in a fixed mol ratio to form products. The reactants react in a fixed molecular ratio to form products.

Molecules are a small unit of mol. We know that 1mol of any substance contains 6.022 x 10²³  molecules of that substance. (Avogadro number).  In a balanced equation, coefficients are used to show the quantities of both the reactants and products in the reaction.

Answer to Problem 3A

  $2NO{\left(g\right)}^{}+O_2\left(g\right)\to 2N{O}_2\left(g\right)$

2 molecules of NO gas react with 1 molecule of O₂ gas to produce 2 molecules of NO₂ gas.

2 moles of NO molecules react with 1 mol of O₂ molecules to produce 2 moles of NO₂ molecules.

Explanation of Solution

  $NO{\left(g\right)}^{}+O_2\left(g\right)\to N{O}_2\left(g\right)$

 The above equation is not balanced because atoms on both sides of the arrow are not equal. The balanced equation is:

  $2NO{\left(g\right)}^{}+O_2\left(g\right)\to 2N{O}_2\left(g\right)$

Now atoms on both sides of the arrow are equal, so the equation is balanced.  

The meaning of the equation in terms of individual molecules:

2 molecules of NO gas react with 1 molecule of O₂ gas to produce 2 molecules of NO₂ gas.

The meaning of the equation in terms of moles of molecules:

2 moles of NO molecules react with 1 mol of O₂ molecules to produce 2 moles of NO₂ molecules.

(b)

Interpretation Introduction

Interpretation:

The meaning of the equation needs to be stated in the terms of numbers of individual molecules and in the terms of moles of molecules.

  $AgC{H}_{3}COO\left(aq\right)+CuS{O}_4\left(aq\right)\to A{g}_{2}S{O}_4\left(s\right) +Cu{\left(C{H}_{3}COO\right)}_2\left(aq\right)$

Concept Introduction:

The balanced equation shows that different reactants react in a fixed mol ratio to form products. The reactants react in a fixed molecular ratio to form products.

Molecules are a small unit of mol. We know that 1mol of any substance contains 6.022 x 10²³  molecules of that substance. (Avogadro number).  In a balanced equation, coefficients are used to show the quantities of both the reactants and products in the reaction.

Answer to Problem 3A

 The balanced equation is:

  $2AgC{H}_{3}COO\left(aq\right)+CuS{O}_4\left(aq\right)\to A{g}_{2}S{O}_4\left(s\right) +Cu{\left(C{H}_{3}COO\right)}_2\left(aq\right)$

When 2 molecules of aqueous  AgCH₃COO react with 1 molecule of aqueous CuSO₄ , 1 molecule of silver sulfate (Ag₂SO₄) precipitated out and 1 molecule of Cu(CH₃COO)₂is the aqueous product.

When 2  moles of aqueous  AgCH₃COO molecules react with 1 mol of aqueous CuSO₄ molecules, 1 mol of (Ag₂SO₄) molecules precipitated out and 1mol of Cu(CH₃COO)₂molecules are the aqueous product.

Explanation of Solution

 The balanced equation is:

  $2AgC{H}_{3}COO\left(aq\right)+CuS{O}_4\left(aq\right)\to A{g}_{2}S{O}_4\left(s\right) +Cu{\left(C{H}_{3}COO\right)}_2\left(aq\right)$

The meaning of the equation in terms of individual molecules:

When 2 molecules of aqueous  AgCH₃COO react with 1 molecule of aqueous CuSO₄ , 1 molecule of silver sulfate (Ag₂SO₄) precipitated out and 1 molecule of Cu(CH₃COO)₂is the aqueous product.

The meaning of the equation in terms of moles of molecules:

When 2  moles of aqueous  AgCH₃COO molecules react with 1 mol of aqueous CuSO₄ molecules, 1 mol of silver sulfate (Ag₂SO₄) molecules precipitated out and 1mol of Cu(CH₃COO)₂molecules are the aqueous product.

(c)

Interpretation Introduction

Interpretation:

The meaning of the equation needs to be stated in the terms of numbers of individual molecules and in the terms of moles of molecules.

  $PC{l}_3\left(l\right)+H_{2}O\left(l\right)\to H_{3}P{O}_3\left(l\right)+HCl\left(g\right)$

Concept Introduction:

The balanced equation shows that different reactants react in a fixed mol ratio to form products. The reactants react in a fixed molecular ratio to form products.

Molecules are a small unit of mol. We know that 1mol of any substance contains 6.022 x 10²³  molecules of that substance. (Avogadro number).  In a balanced equation, coefficients are used to show the quantities of both the reactants and products in the reaction.

Answer to Problem 3A

 The balanced equation is: 

  $PC{l}_3\left(l\right)+3H_{2}O\left(l\right)\to H_{3}P{O}_3\left(l\right)+3HCl\left(g\right)$

When 1 molecule of phosphorus trichloride (PCl₃) reacts with 3 molecules of water, 1 molecule of phosphoric acid(H₃PO₃) and 3 molecules of hydrochloric gas is produced.

When 1 mol of phosphorus trichloride (PCl₃) molecules react with 3 moles of water molecules, 1 mol of phosphoric acid(H₃PO₃) molecules and 3 moles of hydrochloric gas molecules is produced

Explanation of Solution

 The balanced equation is:

  $PC{l}_3\left(l\right)+3H_{2}O\left(l\right)\to H_{3}P{O}_3\left(l\right)+3HCl\left(g\right)$

The meaning of the equation in terms of individual molecules:

When 1 molecule of phosphorus trichloride (PCl₃) reacts with 3 molecules of water, 1 molecule of phosphoric acid(H₃PO₃) and 3 molecules of hydrochloric gas is produced.

The meaning of the equation in terms of moles of molecules:

When 1 mol of phosphorus trichloride (PCl₃) molecules react with 3 moles of water molecules, 1 mol of phosphoric acid(H₃PO₃) molecules and 3 moles of hydrochloric gas molecules is produced.

(d)

Interpretation Introduction

Interpretation:

The meaning of the equation needs to be stated in the terms of numbers of individual molecules and in the terms of moles of molecules.

  $C_2{H}_6\left(g\right)+C{l}_2\left(g\right)\to C_2{H}_{5}Cl\left(g\right)+HCl\left(g\right)$

Concept Introduction:

The balanced equation shows that different reactants react in a fixed mol ratio to form products. The reactants react in a fixed molecular ratio to form products.

Molecules are a small unit of mol. We know that 1mol of any substance contains 6.022 x 10²³  molecules of that substance. (Avogadro number).  In a balanced equation, coefficients are used to show the quantities of both the reactants and products in the reaction.

Answer to Problem 3A

The balanced equation is: 

  $C_2{H}_6\left(g\right)+C{l}_2\left(g\right)\to C_2{H}_{5}Cl\left(g\right)+HCl\left(g\right)$

When 1 molecule of C₂H₆ reacts with 1 molecule of Cl₂ gas, 1 molecule of C₂H₅Cl, and 1 molecule of HCl gas is produced.

When 1 mol of C₂H₆ molecules react with 1 mol of Cl₂ gas molecules, 1 mol of C₂H₅Cl molecules and 1 mol of HCl gas molecules are produced.

Explanation of Solution

The balanced equation is: 

  $C_2{H}_6\left(g\right)+C{l}_2\left(g\right)\to C_2{H}_{5}Cl\left(g\right)+HCl\left(g\right)$

The meaning of the equation in terms of individual molecules:

When 1 molecule of C₂H₆ reacts with 1 molecule of Cl₂ gas, 1 molecule of C₂H₅Cl, and 1 molecule of HCl gas is produced.

The meaning of the equation in terms of moles of molecules:

When 1 mol of C₂H₆ molecules react with 1 mol of Cl₂ gas molecules, 1 mol of C₂H₅Cl molecules and 1 mol of HCl gas molecules are produced.