Q. 7.92 - An Introduction to General, Organic, and Biological Chemistry

Question

Calculate the molar mass for each of the following: ($7.2$)

a. data-custom-editor="chemistry" ${\mathrm{MgCO}}_3$, magnesium carbonate, used in antacids

b. data-custom-editor="chemistry" $\mathrm{Au}{\left(\mathrm{OH}\right)}_3$, gold(III) hydroxide, used in gold plating

c. data-custom-editor="chemistry" ${\mathrm{C}}_{18}{\mathrm{H}}_{34}{\mathrm{O}}_2$, oleic acid, from olive oil

d. data-custom-editor="chemistry" ${\mathrm{C}}_{21}{\mathrm{H}}_{26}{\mathrm{O}}_5$, prednisone, anti-inflammatory

Step-by-Step Solution

Answer

(a) The molar mass of given compound is $84.3 \mathrm{g}/\mathrm{mole}$

(b) The molar mass of given compound is $248 \mathrm{g}/\mathrm{mole}$

(c) The molar mass of given compound is $282 \mathrm{g}/\mathrm{mole}$

(d) The molar mass of given compound is $358 \mathrm{g}/\mathrm{mole}$

Part (a) Step 1: Given information

We need to find the molar mass of ${\mathrm{MgCO}}_3$

Part (a) Step 2: Explanation

We know that

Molar mass of magnesium is, $24.3 \mathrm{g}/\mathrm{mole}$

And molar mass of carbon is, $12 \mathrm{g}/\mathrm{mole}$

And molar mass of oxygen is, $16 \mathrm{g}/\mathrm{mole}$

Therefore, required molar mass is,

$24.3 \raisebox{1ex}{$\mathrm{g}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{mol} $}\right.+12 \raisebox{1ex}{$\mathrm{g}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{mol} $}\right.+\left(3\times 16\right) \raisebox{1ex}{$\mathrm{g}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{mol} $}\right.=84.3 \mathrm{g}/\mathrm{mole}$

Part (b) Step 1: Given information

We need to find the molar mass of $\mathrm{Au}{\left(\mathrm{OH}\right)}_3$

Part (b) Step 2: Explanation

We know that

Molar mass of silver is, $197 \mathrm{g}/\mathrm{mole}$

And molar mass of hydrogen is, $1 \mathrm{g}/\mathrm{mole}$

And molar mass of oxygen is, $16 \mathrm{g}/\mathrm{mole}$

Therefore, required molar mass is,

$197 \raisebox{1ex}{$\mathrm{g}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{mol} $}\right.+3\times \left(16+1\right) \raisebox{1ex}{$\mathrm{g}$}\!\left/ \!\raisebox{-1ex}{$\mathrm{mol} $}\right.=248 \mathrm{g}/\mathrm{mole}$

Part (c) Step 1: Given information

We need to find the molar mass of ${\mathrm{C}}_{18}{\mathrm{H}}_{34}{\mathrm{O}}_2$

Part (c) Step 2: Explanation

We know that

Molar mass of hydrogen is, $1 \mathrm{g}/\mathrm{mole}$

And molar mass of carbon is, $12 \mathrm{g}/\mathrm{mole}$

And molar mass of oxygen is, $16 \mathrm{g}/\mathrm{mole}$

Therefore, required molar mass is,

$282 \mathrm{g}/\mathrm{mole}$

Part (d) Step 1: Given information

We need to find the molar mass of ${\mathrm{C}}_{21}{\mathrm{H}}_{26}{\mathrm{O}}_5$

Part (d) Step 2: Explanation

We know that

Molar mass of hydrogen is, $1 \mathrm{g}/\mathrm{mole}$

And molar mass of carbon is, $12 \mathrm{g}/\mathrm{mole}$

And molar mass of oxygen is, $16 \mathrm{g}/\mathrm{mole}$

Therefore, required molar mass is,

$358 \mathrm{g}/\mathrm{mole}$