Question 1

How do I convert grams to moles?

Accepted Answer

Divide the mass in grams by the molar mass of the substance. moles = grams / molar mass. For example, 36 g of water (molar mass 18.015 g/mol) = 36 / 18.015 = 2.0 moles.

Question 2

How do I convert moles to grams?

Accepted Answer

Multiply the number of moles by the molar mass. grams = moles × molar mass. For example, 3 moles of NaCl (molar mass 58.44 g/mol) = 3 × 58.44 = 175.32 grams.

Question 3

What is the difference between a mole and a molecule?

Accepted Answer

A molecule is a single particle made of bonded atoms (like one water molecule H₂O). A mole is a counting unit equal to 6.022 × 10²³ particles. One mole of water contains 6.022 × 10²³ water molecules.

Question 4

Where do I find the molar mass?

Accepted Answer

Look up atomic masses on the periodic table and add them for each atom in the formula. For H₂O: 2(1.008) + 15.999 = 18.015 g/mol. Many references and our molecular weight calculator can do this for you.

Mole Calculator

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