How many grams in one mole?

Answer 1

That depends on the substance, and on whether you are considering atoms ore molecules. One mole has as many grams as the atomic or molecular mass of the substance. For example, one mole of atomic hydrogen has 1 gram; one mole of molecular hydrogen has 2 grams, one mole water has 18 grams, etc., since those numbers are the corresponding atomic or molecular masses.

Answer 2

Unless you state the specific chemical that you are talking about, you have no way of knowing what one mole of it will weigh. A mole is not a unit of weight, it is a specific number of either atoms or molecules (that number being approximately 6.023 x 1023).