Q. 7.100 - An Introduction to General, Organic, and Biological Chemistry

Question

Balance each of the following chemical equations, and identify the type of reaction: ($7.4, 7.5$) 

a. ${\mathrm{Si}}_3{\mathrm{N}}_4\left(\mathrm{s}\right) \to \mathrm{Si}\left(\mathrm{s}\right) + {\mathrm{N}}_2\left(\mathrm{g}\right)$

b. $\mathrm{Mg}\left(\mathrm{s}\right) + {\mathrm{N}}_2\left(\mathrm{g}\right) \to {\mathrm{Mg}}_3{\mathrm{N}}_2\left(\mathrm{s}\right)$

c. $\mathrm{Al}\left(\mathrm{s}\right) + {\mathrm{H}}_2{\mathrm{PO}}_4\left(\mathrm{aq}\right) \to {\mathrm{H}}_2\left(\mathrm{g}\right) + {\mathrm{AIPO}}_4\left(\mathrm{aq}\right)$

d. ${\mathrm{C}}_3{\mathrm{H}}_4\left(\mathrm{g}\right) + {\mathrm{O}}_2\left(\mathrm{g}\right)\to {\mathrm{CO}}_2\left(\mathrm{g}\right) + {\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)$

e. ${\mathrm{Cr}}_2{\mathrm{O}}_3\left(\mathrm{s}\right) + {\mathrm{H}}_2\left(\mathrm{g}\right)\to \mathrm{Cr}\left(\mathrm{s}\right) + {\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)$

f. $\mathrm{Al}\left(\mathrm{s}\right) + {\mathrm{Cl}}_2\left(\mathrm{g}\right)\to {\mathrm{AlCl}}_3\left(\mathrm{s}\right)$

g. ${\mathrm{MgCl}}_2\left(\mathrm{aq}\right) + {\mathrm{AgNO}}_3\left(\mathrm{aq}\right) \to \mathrm{AgCl}\left(\mathrm{s}\right) + \mathrm{Mg}{\left({\mathrm{NO}}_3\right)}_2\left(\mathrm{aq}\right)$

Step-by-Step Solution

Answer

(a) The required balanced equation is ${\mathrm{Si}}_3{\mathrm{N}}_4\to 3\mathrm{Si}+ 2{\mathrm{N}}_2$ and the type of reaction is a combination

(b) The required balanced equation is $3\mathrm{Mg}+{\mathrm{N}}_2\to {\mathrm{Mg}}_3{\mathrm{N}}_2$ and the type of reaction is combination

(c) The required balanced equation is $2\mathrm{Al}+2{\mathrm{H}}_3{\mathrm{PO}}_4\to 2{\mathrm{AlPO}}_4+3{\mathrm{H}}_2$ and the type of reaction is a single replacement

(d) The required balanced equation is ${\mathrm{C}}_3{\mathrm{H}}_4+4{\mathrm{O}}_2\to 3{\mathrm{CO}}_2+2{\mathrm{H}}_2\mathrm{O}$ and the type of reaction is a combustion

(e) The required balanced equation is ${\mathrm{Cr}}_2{\mathrm{O}}_3+3{\mathrm{H}}_2\to 2\mathrm{Cr}+3{\mathrm{H}}_2\mathrm{O}$ and the type of reaction is a single replacement

(f) The required balanced equation is $2\mathrm{Al}+3{\mathrm{Cl}}_2\to 2{\mathrm{AlCl}}_3$ and the type of reaction is a combination

(g) The required balanced equation is ${\mathrm{MgCl}}_2+{\mathrm{AgNO}}_3\to \mathrm{Mg}{\left({\mathrm{NO}}_3\right)}_2+2\mathrm{AgCl}$ and the type of reaction is a double replacement 

Part (a) Step 1: Given information

We need to find the balanced equation and type of the reaction 

Part (a) Step 2: Explanation

We know that

The balance equation is that in which total mass of reactant is equal to total mass of products

Therefore, The required balanced equation is,

${\mathrm{Si}}_3{\mathrm{N}}_4\to 3\mathrm{Si}+2{\mathrm{N}}_2$

And from the above equation we can interpret the type of reaction i.e. combination

Part (b) Step 1: Given information

We need to find the balanced equation and type of the reaction  

Part (b) Step 2: Explanation

We know that

The balance equation is that in which total mass of reactant is equal to total mass of products

Therefore, The required balanced equation is,

$3\mathrm{Mg}+{\mathrm{N}}_2\to {\mathrm{Mg}}_3{\mathrm{N}}_2$

And from the above equation we can interpret the type of reaction i.e. combination

Part (c) Step 1: Given information

We need to find the balanced equation and type of the reaction 

Part (c) Step 2: Explanation

We know that

The balance equation is that in which total mass of reactant is equal to total mass of products

Therefore, The required balanced equation is,

$2\mathrm{Al} + 2{\mathrm{H}}_3{\mathrm{PO}}_4\to 2{\mathrm{AlPO}}_4+3{\mathrm{H}}_2$

And from the above equation, we can interpret the type of reaction i.e. single replacement

Part (d) Step 1: Given information

We need to find the balanced equation and type of the reaction  

Part (d) Step 2: Explanation

We know that

The balance equation is that in which total mass of reactant is equal to total mass of products

Therefore, The required balanced equation is,

${\mathrm{C}}_3{\mathrm{H}}_4+4{\mathrm{O}}_2\to 3{\mathrm{CO}}_2+2{\mathrm{H}}_2\mathrm{O}$

And from the above equation we can interpret the type of reaction i.e. combustion

Part (e) Step 1: Given information

We need to find the balanced equation and type of the reaction 

Part (e) Step 2: Explanation

We know that

The balance equation is that in which total mass of reactant is equal to total mass of products

Therefore, The required balanced equation is,

${\mathrm{Cr}}_2{\mathrm{O}}_3+3{\mathrm{H}}_2\to 2\mathrm{Cr}+3{\mathrm{H}}_2\mathrm{O}$

And from the above equation we can interpret the type of reaction i.e. single replacement 

Part (f) Step 1: Given information

We need to find the balanced equation and type of the reaction  

Part (f) Step 2: Explanation

We know that

The balance equation is that in which total mass of reactant is equal to total mass of products

Therefore, The required balanced equation is,

$2\mathrm{Al}+3{\mathrm{Cl}}_2\to 2{\mathrm{AlCl}}_3$

And from the above equation we can interpret the type of reaction i.e. combination

Part (g) Step 1: Given information

We need to find the balanced equation and type of the reaction  

Part (g) Step 2: Explanation

We know that

The balance equation is that in which total mass of reactant is equal to total mass of products

Therefore, The required balanced equation is,

${\mathrm{MgCl}}_2+{\mathrm{AgNO}}_3\to \mathrm{Mg}{\left({\mathrm{NO}}_3\right)}_2+2\mathrm{AgCl}$

And from the above equation we can interpret the type of reaction i.e. double replacement