Naphthalene, commonly known as moth balls, is composed of 93.7% carbon and 6.3% hydrogen.

determine the empirical for naphthalene.
molecular formula for Naphthalene. Determine the number of empirical formulas you would need to make a full naphthalene molecule.

1. 93.7g C x mole/12.00g C =7.8

6.3g H x mole/1.01g H =6.23

2. divide the smallest number. (6.23)
H 6.23/6.23 =1
C 7.8/ 6.2= 1.25

3. Multiply by 4.
H 1x4 = 4
C 1.25x4 = 5

4. Empirical formula is C5H4

Take a 100 g sample which will give you

93.7 g C
6.3% H.
Convert each to mols.
93.7/12 = ?
6.4./1 = ?
Now find the ratio of the two and that gives the empirical formula. There isn't enough information to find the molecular formula.

Why multiply by 4???

To determine the empirical formula of naphthalene, we need to determine the simplest whole number ratio of the elements in the compound.

We are given that naphthalene is composed of 93.7% carbon and 6.3% hydrogen.

Step 1: Convert the percentages to grams.
Assuming we have 100 grams of naphthalene, 93.7 grams is carbon and 6.3 grams is hydrogen.

Step 2: Convert grams to moles.
To convert grams to moles, we need to divide the given mass by the molar mass of each element. The molar masses of carbon and hydrogen are approximately 12.01 g/mol and 1.01 g/mol, respectively.

Number of moles of carbon = 93.7 g / 12.01 g/mol ≈ 7.80 mol
Number of moles of hydrogen = 6.3 g / 1.01 g/mol ≈ 6.23 mol

Step 3: Divide each mole value by the smallest mole value.
Dividing both values by 6.23 (the smallest mole value), we get approximately:

Carbon: 7.80 mol / 6.23 mol ≈ 1.25
Hydrogen: 6.23 mol / 6.23 mol = 1

Step 4: Convert the ratio to whole numbers.
To obtain whole number ratios, we can multiply each value by a common factor to eliminate any decimal points. In this case, multiplying by 4 will yield whole numbers.

Carbon: 1.25 × 4 = 5
Hydrogen: 1 × 4 = 4

Therefore, the empirical formula of naphthalene is C5H4.

To determine the molecular formula of naphthalene, we need to know its molar mass. The molar mass of naphthalene is approximately 128.17 g/mol.

Step 5: Calculate the empirical formula's molar mass.
To calculate the empirical formula's molar mass, we need to multiply the molar mass of each element by the respective subscripts in the formula.

Molar mass of carbon (C): 12.01 g/mol × 5 = 60.05 g/mol
Molar mass of hydrogen (H): 1.01 g/mol × 4 = 4.04 g/mol

The empirical formula's molar mass is approximately 60.05 g/mol + 4.04 g/mol = 64.09 g/mol.

Step 6: Calculate the number of empirical formulas needed.
Dividing the molar mass of the molecular formula (128.17 g/mol) by the molar mass of the empirical formula (64.09 g/mol) will give us the number of empirical formulas needed to make a full naphthalene molecule.

Number of empirical formulas needed = 128.17 g/mol / 64.09 g/mol ≈ 2

Therefore, to make a full naphthalene molecule, you would need two empirical formulas of C5H4.