Q. 7.22 - An Introduction to General, Organic, and Biological Chemistry

Question

Calculate the mass, in grams, for each of the following: 

a. $5.12$ moles of $Al$

b .$0.75$ mole of$Cu$

c. $3.52$ moles of $MgB{r}_2$

d. $0.145$ mole of $C_2{H}_{6}O$

e. $2.08$moles of ${\left(NH4\right)}_{2}S{O}_4$

Step-by-Step Solution

Answer

The mass, in grams, for each of the following :

a. $5.12$ moles of $Al$ is $138$g

b. $0.75$ moles of $Cu$ is $47.7$ g

c. $3.52$ moles of $MgB{r}_2$ is $648$g        

d. $0.145$mole of $C_2{H}_6{O}_{}$is$6.68015$g

e. $2.08$ moles of ${\left(NH4\right)}_{2}S{O}_4$ is $274.8$g

Part (a) Step 1: Given information

We need to find the mass in grams 

Part (a) Step 2: Explanation

Here one mole is atomic mass of substance expressed in grams .

Here we will use the formula , we are given with the moles and we know molar mass of substance , so we get;

Number of moles=gram molecular weight/molar mass .

Therefore mass of $5.12$ mole is $5.12 \cancel{moles} \times 26.9 \frac{g}{\cancel{moles}}=138$ g

Part (b) Step 1: Given information

We need to find the mass in grams 

Part (b) Step 2: Explanation

Here one mole is atomic mass of substance expressed in grams .

Here we will use the formula , we are given with the moles and we know molar mass of substance , so we get;

Number of moles=gram molecular weight/molar mass .

Therefore mass of $0.75$ moles  $=0.75\cancel{ moles} \times 63.54 \frac{g}{\cancel{moles}}=47.7$g 

Part (c) Step 1: Given information

We need to find the mass in grams 

Part (c) Step 2: Explanation

Here  one mole is atomic mass of substance expressed in grams .

Here we will use the formula , we are given with the moles and we know molar mass of substance , so we get;

Number of moles=gram molecular weight/molar mass .

Therefore mass of $3.52$ moles $=3.52 \cancel{moles} \times 184.1 \frac{g}{\cancel{moles}}=648$g 

Part (d) Step 1: Given information

We need to find the mass in grams 

Part (d) Step 2: Explanation

Here one mole is atomic mass of substance expressed in grams .

Here we will use the formula , we are given with the moles and we know molar mass of substance , so we get;

Number of moles=gram molecular weight/molar mass .

Therefore mass of $0.145$ mole $=0.145 \cancel{moles }\times 46.07 \frac{g}{\cancel{moles}}=6.68015$g

Part (e) Step 1: Given information

We need to find the mass in grams 

Part (e) Step 2: Explanation

Here one mole is atomic mass of substance expressed in grams .

Here we will use the formula , we are given with the moles and we know molar mass of substance , so we get;

Number of moles=gram molecular weight/molar mass .

Therefore mass of $2.08$ mole $=2.08 \cancel{moles}\times 132.14 \frac{g}{\cancel{moles}}=274.8$ g