Chemistry
Calculator for Molar Mass
Find mass of one mole of compound from its chemical formula, with each element contribution beside am.
Add to workspaceYour numbers
Enter element symbols with counts. You fit use brackets, like Ca(OH)2. Results dey update as you dey type. All calculations dey run inside your browser.
Molar mass
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Formula
Molar mass for g/mol = Σ (number of atoms of each element × its atomic weight for di table). For Ca(OH)2, di subscript 2 multiply both O and H: Ca + 2 × O + 2 × H. Di fixed table use rounded values like H 1.008, C 12.011, N 14.007 and O 15.999.
Example wey show the calculation
With dis table, H2O get molar mass 2 × 1.008 + 15.999 = 18.015 g/mol. Its calculated mass fractions na 2.016 ÷ 18.015 ≈ 11.19% hydrogen and 15.999 ÷ 18.015 ≈ 88.81% oxygen. Other checks from di table na CO2 = 12.011 + 2 × 15.999 = 44.009 g/mol and NaCl = 22.990 + 35.45 = 58.440 g/mol.
Where e fit work and limits
Dis calculator use fixed table of 38 common elements with rounded conventional atomic weights. Enter element symbols, positive integer counts and parentheses, with at most 200 characters and 32 nested groups. E no support charges, isotope labels, structural formulas or dot hydrates; for CuSO4·5H2O enter CuSO4H10O5. Natural isotopic composition fit change atomic weights, so these estimates no be laboratory measurement for one particular sample. Confirm di reference table and uncertainty wey your laboratory work require.
Symbols wey di calculator support: H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Br I Ba Pb Ag Au Hg Sn · Reference: CIAAW shortened standard atomic weights (2024)
Questions wey people dey ask often
Wetin mole mean for chemistry?
One mole contain exactly 6.02214076 × 10²³ elementary entities wey you specify. Molar mass express di mass of one mole for g/mol; di values wey show use dis calculator rounded atomic-weight table.
Why water na 18.015 instead of 18?
Hydrogen and oxygen use average atomic weights of 1.008 and 15.999 for dis table. So 2 × 1.008 + 15.999 = 18.015 g/mol. Dis na approximate conventional value; sample wey get enriched isotope fit different.
How brackets dey work?
Number after closing bracket dey multiply everything inside am. For Ca(OH)2, the 2 doubles both O and H: Ca + O2 + H2, giving 40.078 + 2 × 15.999 + 2 × 1.008 = 74.092 g/mol.
Wetin if the calculator no recognise my element?
Di supported symbols dey listed above. Unknown symbol go give error; di calculator no guess mass or invent value for element wey e no support.
How I fit use molar mass for real work?
To change mass to moles, divide grams by molar mass. To change moles to mass, multiply. For example, 36.03 g of water na 36.03 ÷ 18.015 = 2.00 moles.
Molar mass na the same as molecular weight?
The numbers dey match, but units differ. Molecular weight na relative number without unit. Molar mass na that number in g/mol. People often dey use both terms as if dem mean the same thing.
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Results na estimates; dem no replace advice from qualified professional.