The molecular mass of carbon dioxide is 44.01amu 44.01 amu. The molar mass of any compound is the mass in grams of one mole of that compound. One mole of carbon dioxide molecules has a mass of 44.01g 44.01 g. The molar mass is 44.01g/mol 44.01 g/mol for CO2 CO 2. For water, the molar mass is 18.02g/mol 18.02 g/mol. The molar and mass ratios will not be remotely as close for carbon in iron. So you need to know which is which. If you are trying to interpret a ratio don't overthink it, look at what the ratio claims to be. 1 wt% C in Fe claims to be a mass ratio (that's what wt% or weight percent means, if the ratio has been mol% it would have meant a molar You will recall that the molar mass of a pure substance is the mass of 6.02 x 10 23 (Avogadro's number) of particles or molecular units of that substance. Molar masses are commonly expressed in units of grams per mole (g mol –1 ) and are often referred to as molecular weight s. Then, use atomic weights to calculate the moles of each element. Then, assign empirical formula by calculating the molar ratio for each element. Example 3.4. 2: Ascorbic Acid. Vitamin C (ascorbic acid) contains 40.92 % C, 4.58 % H, and 54.50 % O, by mass. The experimentally determined molecular mass is 176 amu. Gas Densities and Molar Mass. The ideal-gas equation can be manipulated to solve a variety of different types of problems. For example, the density, \(\rho\), of a gas, depends on the number of gas molecules in a constant volume. If its molar mass is 52.46 g/mol, then determine the molecular formula of the compound. Solution: Given data: The empirical formula of a compound = HClO. The molar mass of the compound = 52.46 g/mol. First, let’s calculate the empirical formula molar mass. Empirical formula molar mass (EFM) = 1.00794 + 35.453 + 15.9994 = 52.460 g/mol 7vRpBE. The ratio M w /M n is called the molar-mass dispersity index 5 (often called polydispersity). 5 If all the polymer chains are exactly the same, then the number-average and weight-average molecular weights are exactly the same and the polydispersity is “1.” The larger the molar-mass dispersity index, the wider the molecular weight distribution. e.g. The formula weight of H2O = 2x Atomic Weight of H (2x1.008) + Atomic Weight of O(15.999) = 18.015. Formula weight of molecular compound is often called molecular weight. In chemistry, mass and weight are commonly used interchangeably. Mass and Mole. Mass is the amount of a substance in grams, also called weight. The mole is related to the mass of an element in the following way: one mole of carbon-12 atoms has 6.02214076 × 10 23 atoms and a mass of 12 grams. In comparison, one mole of oxygen consists, by definition, of the same number of atoms as carbon-12, but it has a mass of 15.999 grams. Oxygen, therefore, has a greater mass than carbon. In the same way, the mole always refers to 6.022x10^23 of something. So a mole of carbon versus a mole of iron still means the same number of carbon atoms and iron atoms. That being said, just because something is equal in number doesn't mean it's equal in mass; a dozen textbooks is obviously much heavier than a dozen eggs. The mass of the component divided by the molar mass of the compound times 100. True or false: the empirical formula is always the same as the molecular formula. Molar volume. In chemistry and related fields, the molar volume, symbol Vm, [1] or of a substance is the ratio of the volume occupied by a substance to the amount of substance, usually given at a given temperature and pressure. It is equal to the molar mass ( M) divided by the mass density ( ρ ): The molar volume has the SI unit of cubic

is molecular mass and molar mass the same