Calculate the formula mass of ethanol C2H5OH.

Steps to Solve

1. Identify the atoms in ethanol

The chemical formula for ethanol is $C_2H_5OH$. This means it contains:

• 2 Carbon (C) atoms
• 6 Hydrogen (H) atoms (5 from $H_5$ and 1 from $OH$)
• 1 Oxygen (O) atom

2. Find the atomic masses of the elements

Using the periodic table, we find the approximate atomic masses for each element:

• Carbon (C): approximately 12.01 g/mol
• Hydrogen (H): approximately 1.008 g/mol
• Oxygen (O): approximately 16.00 g/mol

3. Calculate the total mass for each element

Now, we will calculate the total mass contributed by each element in the formula:

• For Carbon: $$ \text{Mass from Carbon} = 2 \times 12.01 , \text{g/mol} = 24.02 , \text{g/mol} $$

• For Hydrogen: $$ \text{Mass from Hydrogen} = 6 \times 1.008 , \text{g/mol} = 6.048 , \text{g/mol} $$

• For Oxygen: $$ \text{Mass from Oxygen} = 1 \times 16.00 , \text{g/mol} = 16.00 , \text{g/mol} $$

4. Add the total masses together

Finally, we can find the total formula mass by adding the contributions from each element:

$$ \text{Total Mass} = \text{Mass from Carbon} + \text{Mass from Hydrogen} + \text{Mass from Oxygen} $$

Substituting the values: $$ \text{Total Mass} = 24.02 , \text{g/mol} + 6.048 , \text{g/mol} + 16.00 , \text{g/mol} $$

5. Calculate the final formula mass

Now, let's perform the final calculation:

$$ \text{Total Mass} = 24.02 + 6.048 + 16.00 = 46.068 , \text{g/mol} $$