Answer :

To find the mass of 1.57 moles of [tex]\( C_4H_5OH \)[/tex], we need to follow these steps:

1. Determine the Molar Mass of [tex]\( C_4H_5OH \)[/tex]:
The compound [tex]\( C_4H_5OH \)[/tex] is composed of carbon (C), hydrogen (H), and oxygen (O). Here's how to calculate the molar mass:

- Carbon (C): There are 4 carbon atoms. The molar mass of one carbon atom is approximately 12.01 g/mol.
So, the total mass from carbon is [tex]\( 4 \times 12.01 = 48.04 \, \text{g/mol} \)[/tex].

- Hydrogen (H): There are 6 hydrogen atoms (5 from [tex]\( C_4H_5 \)[/tex] and 1 from OH). The molar mass of one hydrogen atom is approximately 1.008 g/mol.
So, the total mass from hydrogen is [tex]\( 6 \times 1.008 = 6.048 \, \text{g/mol} \)[/tex].

- Oxygen (O): There is 1 oxygen atom. The molar mass of one oxygen atom is approximately 16.00 g/mol.
So, the total mass from oxygen is [tex]\( 1 \times 16.00 = 16.00 \, \text{g/mol} \)[/tex].

Adding these together gives the molar mass of [tex]\( C_4H_5OH \)[/tex]:
[tex]\[
48.04 \, \text{g/mol} + 6.048 \, \text{g/mol} + 16.00 \, \text{g/mol} = 70.088 \, \text{g/mol}
\][/tex]

2. Calculate the Mass of 1.57 Moles of [tex]\( C_4H_5OH \)[/tex]:
To find the mass of a given number of moles, multiply the number of moles by the molar mass:
[tex]\[
\text{Mass} = \text{Number of moles} \times \text{Molar mass}
\][/tex]
[tex]\[
\text{Mass} = 1.57 \, \text{mol} \times 70.088 \, \text{g/mol} = 110.03816 \, \text{g}
\][/tex]

Thus, the mass of 1.57 moles of [tex]\( C_4H_5OH \)[/tex] is approximately 110.04 grams.