Q. 7.28 - An Introduction to General, Organic, and Biological Chemistry

Question

Calculate the number of moles in $4.0$ g of each of the following:

a. $Au$ 

b. $Sn{O}_2$

c. $C{S}_2$ 

d. $C{a}_3 N_2$

e. $C_6{H}_8{O}_6$, vitamin C 

Step-by-Step Solution

Answer

 The number of moles in $4.00$ g of each of the following: 

 a.$0.02$ moles

b.$0.026$ moles

c. $0.052$ moles

d.$0.026$moles

e.$0.022$ moles

Part (a) Step 1: Given information

We need to find the number of moles in $4$ g of $Au$.

Part (a) Step 2: Explanation

Here we need to find number of moles , and formula for it is ;

Number of moles=gram molecular weight/molar mass .

We are given with the gram molecular weight , and we know the molar mass for this element , so we get ;

Therefore,$\frac{4\cancel{ g}}{196.9\cancel{ g}/moles}=0.02$ moles

Part (b) Step 1: Given information

We need to find the number of moles in $4$g of $Sn{O}_2$.

Part (b) Step 2: Explanation

Here we need to find number of moles , and  formula for it is ;

Number of moles=gram molecular weight/molar mass 

We are given with the gram molecular weight , and we know the molar mass for this element , so we get ;

Therefore,$\frac{4\cancel{ g}}{150.71\cancel{ g}/moles}=0.026$ moles

Part (c) Step 1: Given information

We need to find the number of moles in $4$g of $C{S}_2$ .

Part (c) Step 2: Explanation

Here we need to find number of moles , and formula for it is ;

Number of moles=gram molecular weight/molar mass 

We are given with the gram molecular weight , and we know the molar mass for this element , so we get ;

Therefore,$\frac{4\cancel{ g}}{76.13\cancel{ g}/moles}=0.052$ moles

Part (d) Step 1: Given information

We need to find the number of moles in $4$g of $C{a}_3{N}_2$.

Part (d) Step 2: Explanation

Here we need to find number of moles , and formula for it is ;

Number of moles=gram molecular weight/molar mass 

We are given with the gram molecular weight , and we know the molar mass for this element , so we get ;

Therefore,$\frac{4\cancel{ g}}{148.25\cancel{ g}/moles}=0.026$ moles

Part (e) Step 1: Given information

We need to find the number of moles in $4$g of $C_6{H}_8{O}_6$.

Part (e) Step 2: Explanation

Here we need to find number of moles , and formula for it is ;

Number of moles=gram molecular weight/molar mass 

We are given with the gram molecular weight , and we know the molar mass for this element , so we get ;

Therefore,$\frac{4\cancel{ g}}{176.12\cancel{ g}/moles}=0.022$moles