Convert molecules to grams, grams to molecules or moles to grams for water, CO2, NaCl, glucose and other substances, or enter a custom molar mass.
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Molecules to Gram Formula
The following formula is used to calculate the mass in grams for a given number of molecules and molar mass.
Variables:
- m is the mass in grams
- N is the number of molecules (or formula units for an ionic solid)
- M is the molar mass in grams per mole (g/mol)
- NA is Avogadro’s number (exactly 6.02214076 × 1023 molecules per mole)
To calculate the mass in grams, multiply the number of molecules by the molar mass and then divide by Avogadro’s number.
| Molecules | Grams (g) | Kilograms (kg) | Pounds (lb) | Ounces (oz) |
|---|---|---|---|---|
| 5e19 | 0.001 | 0.000 | 0.000 | 0.000 |
| 1e20 | 0.003 | 0.000 | 0.000 | 0.000 |
| 2e20 | 0.006 | 0.000 | 0.000 | 0.000 |
| 5e20 | 0.015 | 0.000 | 0.000 | 0.001 |
| 7.5e20 | 0.022 | 0.000 | 0.000 | 0.001 |
| 1e21 | 0.030 | 0.000 | 0.000 | 0.001 |
| 2e21 | 0.060 | 0.000 | 0.000 | 0.002 |
| 5e21 | 0.150 | 0.000 | 0.000 | 0.005 |
| 7.5e21 | 0.224 | 0.000 | 0.000 | 0.008 |
| 1e22 | 0.299 | 0.000 | 0.001 | 0.011 |
| 2.5e22 | 0.748 | 0.001 | 0.002 | 0.026 |
| 5e22 | 1.496 | 0.001 | 0.003 | 0.053 |
| 7.5e22 | 2.244 | 0.002 | 0.005 | 0.079 |
| 1e23 | 2.992 | 0.003 | 0.007 | 0.106 |
| 2.5e23 | 7.479 | 0.007 | 0.016 | 0.264 |
| 5e23 | 14.958 | 0.015 | 0.033 | 0.528 |
| 6.02214076e23 | 18.015 | 0.018 | 0.040 | 0.635 |
| 7.5e23 | 22.436 | 0.022 | 0.049 | 0.791 |
| 1e24 | 29.915 | 0.030 | 0.066 | 1.055 |
| 2.5e24 | 74.788 | 0.075 | 0.165 | 2.638 |
| * Rounded to 3 decimals. Assumes water (M = 18.01528 g/mol) and Avogadro’s constant N_A = 6.02214076×10^23 mol^-1. Mass m (g) = N × M / N_A. Unit conversions: 1 kg = 1000 g, 1 lb = 453.592 g, 1 oz = 28.3495 g. | ||||
What is a Molecule?
A molecule is an electrically neutral group of two or more bonded atoms. Ionic solids such as sodium chloride are counted in formula units rather than discrete molecules. Molecules are the building blocks of matter and can vary greatly in size and complexity. They can consist of atoms of the same element, such as O2 (oxygen gas), or different elements, such as H2O (water). Molecules are involved in chemical reactions and are essential to the structure and function of living organisms.
How to Calculate Molecules to Gram?
The following steps outline how to calculate the mass in grams from the number of molecules and molar mass.
- First, determine the number of molecules (N).
- Next, determine the molar mass (M) in grams per mole.
- Use Avogadro’s number (NA) which is exactly 6.02214076 × 1023 molecules per mole.
- Calculate the mass in grams using the formula m = (N * M) / NA.
- After inserting the values and calculating the result, check your answer with the calculator above.
Example Problem :
Use the following variables as an example problem to test your knowledge.
Number of molecules (N) = 1.2044 × 1024
Molar mass (M) = 18 g/mol
