Q. 7.18 - An Introduction to General, Organic, and Biological Chemistry

Question

Calculate the molar mass for each of the following:

a. ${\mathrm{C}}_3{\mathrm{H}}_8\mathrm{O}$ , rubbing alcohol

b. ${\left({\mathrm{NH}}_4\right)}_{2}C{O}_3$ , baking powder

c. $\mathrm{Zn}{\left({\mathrm{C}}_2{\mathrm{H}}_3{\mathrm{O}}_2\right)}_2$, zinc supplement

Step-by-Step Solution

Answer

a. The molar mass of ${\mathrm{C}}_3{\mathrm{H}}_8\mathrm{O}$ is $60.02 \mathrm{g}$

b. The molar mass of ${\left({\mathrm{NH}}_4\right)}_{2}C{O}_3$ is $95.98 \mathrm{g}$

c. The molar mass of $\mathrm{Zn}{\left({\mathrm{C}}_2{\mathrm{H}}_3{\mathrm{O}}_2\right)}_2$ is $183.38 \mathrm{g}$

Part (a) Step 1 : Given information

We have to find the molar mass of ${\mathrm{C}}_3{\mathrm{H}}_8\mathrm{O}$

Part (a) Step 2 : Simplification

We know that,

Molar mass of one $\mathrm{C}$ atom = $12.01 \mathrm{g}$

Molar mass of one $\mathrm{H}$ atom = $1.00 \mathrm{g}$

Molar mass of one $\mathrm{O}$ atom = $15.99 \mathrm{g}$

So, the molar mass of ${\mathrm{C}}_3{\mathrm{H}}_8\mathrm{O}$ = $3\left(12.01\right) + 8\left(1.00\right) + 15.99$ = $60.02 \mathrm{g}$

Part (b) Step 1 : Given information

We have to find the molar mass of ${\left({\mathrm{NH}}_4\right)}_{2}C{O}_3$

Part (b) Step 2 : Simplification

We know that,

Molar mass of one $\mathrm{N}$ atom = $14.00 \mathrm{g}$

Molar mass of one $\mathrm{H}$ atom = $1.00 \mathrm{g}$

Molar mass of one $\mathrm{C}$ atom = $12.01 \mathrm{g}$

Molar mass of one $\mathrm{O}$ atom = $15.99 \mathrm{g}$

So, the molar mass of ${\left({\mathrm{NH}}_4\right)}_{2}C{O}_3$ = $2\left(14.00\right) + 8\left(1.00\right) + 12.01 + 3\left(15.99\right)$ = $95.98 \mathrm{g}$

Part (c) Step 1 : Given information

We have to find the molar mass of $\mathrm{Zn}{\left({\mathrm{C}}_2{\mathrm{H}}_3{\mathrm{O}}_2\right)}_2$

Part (c) Step 2 : Simplification

We know that,

Molar mass of one $\mathrm{Zn}$ atom = $65.38 \mathrm{g}$

Molar mass of one $\mathrm{C}$ atom = $12.01 \mathrm{g}$

Molar mass of one $\mathrm{H}$ atom = $1.00 \mathrm{g}$

Molar mass of one $\mathrm{O}$ atom = $15.99 \mathrm{g}$

So, the molar mass of $\mathrm{Zn}{\left({\mathrm{C}}_2{\mathrm{H}}_3{\mathrm{O}}_2\right)}_2$ = $65.38 + 4\left(12.01\right) + 6\left(1.00\right) + 4\left(15.99\right)$ = $183.38 \mathrm{g}$