The molar mass of O2 is 32 g/.mol If you want a more precise value: 31.998g/mol . Weights of atoms and isotopes are from NIST article. Oxygen is the chemical element with the symbol O and atomic number 8. It would be 32 because there are 2 moles of oxygen in O2 and the molar mass of O is 16 so 16x2 = 32. n factor and equivalent weight are not values that are used in modern chemistry . Give us feedback about your experience with Molecular Weight Calculator. The molar mass of atoms of an element is given by the relative atomic mass of the element multiplied by the molar mass constant, M u ≈ 1.000 000 × 10 −3 kg/mol = 1.000000 g/mol. Molar Mass. The molar mass of O2 is 32 g/mol. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds.After hydrogen and helium, oxygen is the third-most abundant element in the universe by mass. in periodic table you will actually see 16g/mol because it is O. For normal samples from earth with typical isotope composition, the atomic weight can be approximated by the standard atomic weight or the conventional atomic weight. Is it 16 or 32? Molar mass (molar weight) is the mass of one mole of a substance and is expressed in g/mol. Mass of 1 mole of O2 gas= 32g Volume occupied by 1 mole of gas at STP =22.4L (by Avogadro's law) Density of O2 gas at STP= 1.42g/L What is the molar mass of O2 (the 2 is a subscript). Glucose is composed of hydrogen (H), carbon (C), and oxygen (O) The molar mass of H is 1.0079, the molar mass of C is 12.0107, and the molar mass of O is 15.9994. 1 decade ago. The molar mass of oxygen gas (O2) is 32. If you look on the periodic table of elements the numbers underneath the symbols for the elements are their molar mass in grams The molar mass of glucose can be calculated by multiplying the molar masses of its atomic constituents by their frequency in a single molecule and adding those values together. Related: Molecular weights of amino acids: molecular weights calculated today: This relationship is frequently used in the laboratory. The molar mass of any substance is the mass in grams of one mole of representative particles of that substance.The representative particles can be atoms, molecules, or formula units of ionic compounds. I did a search in Wikipedia: Equivalent weight (also known as gram equivalent) is a term which has been used in … You should note (in light of the wrong responses above) that the atomic molar mass of Oxygen, O (not O2) is 16 g/mol. 0 0. Don't be confused. Fatima A.