The molar mass of matter is the ratio of the mass of substance to the number of moles of the substance. The molar mass of each chemical compound can be calculated by specific experiments that are aimed at the determination of the density of its vapors and/or other specific experimental techniques. However, the molar mass of each existing or even hypothetical chemical compound can be determined by examining its molecular structure. Therefore, the molar mass of complex molecules can be determined by summing the molar masses of their constituent elements. In our case, this process is quite easy. According to the molecular structure of benzene, it contains six carbon atoms and six hydrogen atoms. The molar mass of carbon is 12 g/mol and the molar mass of hydrogen is 1 g/mol. Thus, we have to multiply the number of atoms of each element by its mass and sum the resulting numbers.