Chapter 10, Problem 51E

(a)

To determine

The missing number in the given equation has to be inserted.

Answer to Problem 51E

A chemical reaction is represented in shorthand by expressing it in chemical equation.  The reactants are entered in left side of the arrow and products are entered in right side of the arrow.  A chemical reaction has to be correctly represented means; the chemical equation has to be balanced.  This is known as balanced chemical equation.  This means the total number of atoms of each kind must be same in the product and reactant side.  This is because atoms can neither be created nor be destroyed.

Explanation of Solution

The given equation is,

$\text{Ca}\text{+}[?]{\text{H}}_{\text{2}}\text{O}\stackrel{}{\to }{\text{Ca(OH)}}_{\text{2}}\text{+}{\text{H}}_{\text{2}}$

To find the missing number in the above equation, we have to find the atoms that are present in the reactant side.  We find that hydrogen and oxygen is present with the unknown coefficient that has to be found out.  When looking into the same hydrogen and oxygen atoms in the right side of the equation, there are two oxygen atoms and four hydrogen atoms.  Therefore, adding coefficient “2” in the reactant side would make the equation balanced.  The balanced equation can be written as,

$\text{Ca}\text{+}2{\text{H}}_{\text{2}}\text{O}\stackrel{}{\to }{\text{Ca(OH)}}_{\text{2}}\text{+}{\text{H}}_{\text{2}}$

Conclusion:

The missing number in the given equation was found out.

(b)

To determine

The missing number in the given equation has to be inserted.

Answer to Problem 51E

A chemical reaction is represented in shorthand by expressing it in chemical equation.  The reactants are entered in left side of the arrow and products are entered in right side of the arrow.  A chemical reaction has to be correctly represented means; the chemical equation has to be balanced.  This is known as balanced chemical equation.  This means the total number of atoms of each kind must be same in the product and reactant side.  This is because atoms can neither be created nor be destroyed.

Explanation of Solution

The given equation is,

$\text{2Al}\text{+}[?]{\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}\stackrel{}{\to }{\text{Al}}_{\text{2}}{{\text{(SO}}_{\text{4}}\text{)}}_{\text{3}}\text{+}3{\text{H}}_{\text{2}}$

To find the missing number in the above equation, we have to find the atoms that are present in the reactant side.  We find that hydrogen, sulfur and oxygen is present with the unknown coefficient that has to be found out.  When looking into the same hydrogen, sulfur and oxygen atoms in the right side of the equation, there are three sulfur atoms, twelve oxygen atoms and six hydrogen atoms.  Therefore, adding coefficient “3” in the reactant side would make the equation balanced.  The balanced equation can be written as,

$\text{2Al}\text{+}3{\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}\stackrel{}{\to }{\text{Al}}_{\text{2}}{{\text{(SO}}_{\text{4}}\text{)}}_{\text{3}}\text{+}3{\text{H}}_{\text{2}}$

Conclusion:

The missing number in the given equation was found out.

(c)

To determine

The missing number in the given equation has to be inserted.

Answer to Problem 51E

A chemical reaction is represented in shorthand by expressing it in chemical equation.  The reactants are entered in left side of the arrow and products are entered in right side of the arrow.  A chemical reaction has to be correctly represented means; the chemical equation has to be balanced.  This is known as balanced chemical equation.  This means the total number of atoms of each kind must be same in the product and reactant side.  This is because atoms can neither be created nor be destroyed.

Explanation of Solution

The given equation is,

${\text{C}}_{\text{7}}{\text{H}}_{\text{16}}\text{+}{\text{11O}}_{\text{2}}\stackrel{}{\to }{\text{7CO}}_{\text{2}}\text{+}[?]{\text{H}}_{\text{2}}\text{O}$

To find the missing number in the above equation, we have to find the atoms that are present in the reactant side.  We find that hydrogen and oxygen is present with the unknown coefficient that has to be found out.  When looking into the same hydrogen, and oxygen atoms in the left side of the equation, there are sixteen hydrogen atoms and twenty two oxygen atoms.  In the product side already fourteen oxygen atoms are present.  Therefore, adding coefficient “8” in the product side would make the equation balanced.  The balanced equation can be written as,

${\text{C}}_{\text{7}}{\text{H}}_{\text{16}}\text{+}{\text{11O}}_{\text{2}}\stackrel{}{\to }{\text{7CO}}_{\text{2}}\text{+}8{\text{H}}_{\text{2}}\text{O}$

Conclusion:

The missing number in the given equation was found out.

(d)

To determine

The missing number in the given equation has to be inserted.

Answer to Problem 51E

A chemical reaction is represented in shorthand by expressing it in chemical equation.  The reactants are entered in left side of the arrow and products are entered in right side of the arrow.  A chemical reaction has to be correctly represented means; the chemical equation has to be balanced.  This is known as balanced chemical equation.  This means the total number of atoms of each kind must be same in the product and reactant side.  This is because atoms can neither be created nor be destroyed.

Explanation of Solution

The given equation is,

${\text{6H}}_{\text{3}}{\text{BO}}_{\text{3}}\stackrel{}{\to }{\text{H}}_{\text{4}}{\text{B}}_{\text{6}}{\text{O}}_{\text{11}}\text{+}[?]{\text{H}}_{\text{2}}\text{O}$

To find the missing number in the above equation, we have to find the atoms that are present in the reactant side.  We find that hydrogen and oxygen is present with the unknown coefficient that has to be found out.  When looking into the same hydrogen, and oxygen atoms in the left side of the equation, there are eighteen hydrogen atoms and eighteen oxygen atoms.  In the product side already eleven oxygen atoms and four hydrogen atoms are present.  Therefore, adding coefficient “7” in the product side would make the equation balanced.  The balanced equation can be written as,

${\text{6H}}_{\text{3}}{\text{BO}}_{\text{3}}\stackrel{}{\to }{\text{H}}_{\text{4}}{\text{B}}_{\text{6}}{\text{O}}_{\text{11}}\text{+}7{\text{H}}_{\text{2}}\text{O}$

Conclusion:

The missing number in the given equation was found out