Moles to grams for toluene is a multiplication by 92.141 g/mol. A mole weighs 92.141 g, 100 mmol weighs 9.2141 g, 10 mmol weighs 0.92141 g and a millimole is 92.141 mg. Those four figures cover most of what gets weighed out in practice, and the table below extends them from a micromole up to ten moles.
The figure comes from the formula. Toluene is 7 × 12.011 (C) + 8 × 1.008 (H), which is 92.141 g/mol, taking standard atomic weights, and every page here computes that sum rather than quoting it. Carbon makes up the largest share of the mass: 7 of the 15 atoms in a formula unit are carbon, and they account for 84.077 g of the 92.141 g, or 91.25% by mass. The derivation table below breaks the whole molecule down element by element.
Two habits make the weighed mass match the calculation. Weigh into a container you have tared rather than onto paper, because what stays behind on paper is a real loss — on a 100 mg weighing it is easily a percent. And when the target is under about 20 mg, weigh ten times that and dilute, since the absolute error of the balance does not shrink with the sample.
Benzene with a methyl group: a paint thinner, an octane booster and the feedstock for TNT and benzoic acid. At 92.141 g/mol it is heavier than 9 of the 21 organic compounds covered here, and that ranking matters more than it looks: glycerol has a molar mass of 92.094 g/mol, so a gram of it contains 0.051% more formula units than a gram of toluene. Weigh by mass and you are not weighing equal amounts of substance.
Two practical things move the result. Purity below 100% means the weighed mass overstates how much compound you have — at 98% assay, 1.8428 g of every 92.141 g is not the compound — and any water picked up from the air does the same. Both are systematic, so they shift every solution made from that jar in the same direction.
The formula
n- The amount of toluene you need, in moles
92.141- The molar mass of toluene in g/mol, derived from its formula
m- The mass to weigh out, in grams
How it works, step by step
- Enter the amount you need, in moles.
- It is multiplied by 92.141 g/mol.
- The result is the mass to weigh out, also given in milligrams.
- Weigh into a tared container; anything left in the boat is a real loss from the amount you calculated.
Worked examples
5 mmol of toluene in grams
5 mmol × 92.141 g/mol = 0.460705 g, which is 460.705 mg. Doubling the amount doubles the mass to 0.92141 g, because the relationship is a plain proportion once the molar mass is fixed.
250 mmol of toluene in grams
250 mmol × 92.141 g/mol = 23.0352 g, which is 23,035.2 mg. Doubling the amount doubles the mass to 46.0705 g, because the relationship is a plain proportion once the molar mass is fixed.
2 mol of toluene in grams
2 mol × 92.141 g/mol = 184.282 g, which is 184,282 mg. Doubling the amount doubles the mass to 368.564 g, because the relationship is a plain proportion once the molar mass is fixed.
How to read your score
Frequently asked questions
What is the molar mass of toluene (C7H8)?
It is 92.141 g/mol. That is the sum of the standard atomic weights of every atom in the formula: 7 × 12.011 (C) + 8 × 1.008 (H). One mole of toluene therefore weighs 92.141 g, and a gram of it is 10.853 mmol.
What percentage of toluene is carbon?
91.25% by mass. Each formula unit contains 7 carbon atoms contributing 84.077 g of the 92.141 g total, so 100 g of toluene contains 91.25 g of carbon and a kilogram contains 912.48 g of it.
How many grams is one mole of toluene?
92.141 g, by definition of the molar mass. Two moles is 184.282 g and half a mole is 46.0705 g.
How many grams is 0.1 mol, and how many milligrams is 1 mmol?
0.1 mol of toluene is 9.2141 g. One millimole is 92.141 mg and one micromole is 92.141 µg, which is the range most bench work sits in.
How do I weigh out an amount too small for my balance?
Weigh a larger mass and dilute it. To get 0.9214 mg of toluene, weigh 9.214 mg into 100 mL, then take 10 mL of that: the absolute error of the balance stays the same while the amount delivered falls by a factor of ten.
Should I use the hydrate or the anhydrous molar mass?
This page is the anhydrous form, C7H8, at 92.141 g/mol. If your jar is the other form the molar mass differs and so will every mass you weigh, so check the label before using the figure. Salts that are sold as hydrates weigh more per mole because the water is part of the crystal.
Moles to grams reference for toluene
| Element | Atoms | Atomic weight | Contribution (g/mol) | By mass |
|---|---|---|---|---|
| Carbon (C) | 7 | 12.011 | 84.077 | 91.25% |
| Hydrogen (H) | 8 | 1.008 | 8.064 | 8.752% |
| Total — one mole of toluene | 92.141 | 100% |
Standard atomic weights, IUPAC 2021. The contribution column is atoms × atomic weight, and the total is the molar mass this page uses: 92.141 g/mol.
| Wanted | Weigh (g) | Weigh (mg) | With 2% over (g) |
|---|---|---|---|
| 1 µmol | 0.000092 | 0.092141 | 0.000094 |
| 10 µmol | 0.00092141 | 0.92141 | 0.000939838 |
| 100 µmol | 0.0092141 | 9.2141 | 0.00939838 |
| 1 mmol | 0.092141 | 92.141 | 0.0939838 |
| 10 mmol | 0.92141 | 921.41 | 0.939838 |
| 50 mmol | 4.60705 | 4607.05 | 4.69919 |
| 100 mmol | 9.2141 | 9214.1 | 9.39838 |
| 250 mmol | 23.0352 | 23,035.2 | 23.496 |
| 500 mmol | 46.0705 | 46,070.5 | 46.9919 |
| 750 mmol | 69.1058 | 69,105.8 | 70.4879 |
| 1 mol | 92.141 | 92,141 | 93.9838 |
| 2 mol | 184.282 | 184,282 | 187.968 |
| 5 mol | 460.705 | 460,705 | 469.919 |
| 10 mol | 921.41 | 921,410 | 939.838 |
Weigh is the amount multiplied by 92.141 g/mol. The last column carries a 2% allowance, which is what you take when some of the solid will be left in the weighing boat.
| Compound | Formula | Molar mass (g/mol) | Millimoles in 1 g |
|---|---|---|---|
| Glycine | C2H5NO2 | 75.067 | 13.321 |
| Benzene | C6H6 | 78.114 | 12.802 |
| Glycerol | C3H8O3 | 92.094 | 10.858 |
| Toluene (this page) | C7H8 | 92.141 | 10.853 |
| Creatinine | C4H7N3O | 113.12 | 8.8402 |
| Octane | C8H18 | 114.232 | 8.7541 |
| Tris base | C4H11NO3 | 121.136 | 8.2552 |
Ordered by molar mass. The last column is 1000/M, which is the number a weighed gram actually gives you.