Answer: To convert grams (g) to moles (mol), we need to use the molar mass of the substance. We can use the following formula:
moles = mass (in grams) / molar mass
We will assume that we are given the mass of a pure substance. If the substance is a compound, we will need to look up the molar mass in the periodic table or calculate it using the atomic masses of its elements.
Let's assume that we are given 18.2 g of a pure substance and we want to convert it to moles. We will need to look up the molar mass of the substance. For example, let's say the substance is water (H2O):
Molar mass of H2O = 2(1.008 g/mol) + 1(15.999 g/mol) = 18.015 g/mol
Now we can use the formula to convert grams to moles:
moles = 18.2 g / 18.015 g/mol = 1.009 mol
Therefore, 18.2 g of the substance is equivalent to 1.009 mol of the substance.