Question

Calculate the number of moles in $25.0$gof each of the following:

a. $He$

b. $O$

c. $Al{\left(OH\right)}_3$

d. $G{a}_2{S}_3$

e. $C_4{H}_{10}$, butane

Short answer

The number of moles in $25.0$g of each of the following :

a. $6.25$moles

b. $1.56$moles

c.$0.32$moles

d.$0.106$moles

e.$0.34$moles

Step-by-step solution

Part (a) Step 1: Given information

We need to find that number of moles in$25.0$g of$He$.

Part (a) Step 2: Explanation

Here we will use the formula of number of moles ,

We are given with gram molecular mass and we know molar mass of substance , so we get;

Number of moles=gram molecular weight/molar mass .

Therefore, number of moles is$\frac{25\cancel{g}}{4\cancel{g}/moles}=6.25$moles

Part (b) Step 1: Given information

We need to find that number of moles in$25.0$gof$O$

Part (b) Step 2: Explanation

Here we will use the formula of number of moles ,

We are given with gram molecular mass and we know molar mass of substance , so we get;

Number of moles=gram molecular weight/molar mass

Therefore, number of moles$\frac{25\cancel{g}}{16\cancel{g}/moles}=1.56$moles

Part (c) Step 1: Given information

We need to find that number of moles in$25.0$gof$Al{\left(OH\right)}_3$

Part (c) Step 2: Explanation

Here we will use the formula of number of moles ,

We are given with gram molecular mass and we know molar mass of substance , so we get;

Number of moles=gram molecular weight/molar mass

Therefore,number of moles$\frac{25\cancel{g}}{78\cancel{g}/moles}=0.32$moles

Part (d) Step 1: Given information

We need to find that number of moles in$25.0$gof$G{a}_2{S}_3$

Part (d) Step 2: Explanation

Here we will use the formula of number of moles ,

We are given with gram molecular mass and we know molar mass of substance , so we get;

Number of moles=gram molecular weight/molar mass

Therefore,number of moles$\frac{25\cancel{g}}{235.6\cancel{g}/moles}=0.106$moles

Part (e) Step 1: Given information

We need to find that number of moles in$25.0$g of$C_4{H}_{10}$.

Part (e) Step 2: Explanation

Here we will use the formula of number of moles ,

We are given with gram molecular mass and we know molar mass of substance , so we get;

Number of moles=gram molecular weight/molar mass

Therefore,number of moles$\frac{25\cancel{g}}{73.14\cancel{g}/moles}=0.34$moles