# How to find moles from grams?

#### Understand the Problem

The question is asking how to convert grams to moles, which involves using the molar mass of a substance. This process typically requires identifying the substance and its molar mass to perform the conversion.

The number of moles = \frac{\text{mass (grams)}}{\text{molar mass (g/mol)}}

The final answer is the number of moles obtained from the conversion.

#### Steps to Solve

1. Determine the substance

Identify the chemical substance you are converting from grams to moles. The substance's molecular formula or name should be given.

1. Find the molar mass

Calculate the molar mass of the substance. This can be done by adding the atomic masses of all the elements in the molecule. For example, for water (H₂O), the molar mass can be calculated as:

• Hydrogen: 2 atoms × 1 g/mol = 2 g/mol\
• Oxygen: 1 atom × 16 g/mol = 16 g/mol\
• Molar mass of H₂O: 2 g/mol + 16 g/mol = 18 g/mol
1. Apply the conversion formula

Use the formula to convert grams to moles:

$$ext{moles} = \frac{ ext{mass (grams)}}{ ext{molar mass (g/mol)}}$$

For example, to convert 36 grams of water (H₂O) to moles:

$$ext{moles} = \frac{36 ext{ g}}{18 ext{ g/mol}} = 2 ext{ moles}$$

The final answer is the number of moles obtained from the conversion.