How can i determine the molar mass of a compound?
The molar mass of a compound is given by the sum of the standard atomic weights of the atoms which form the compound multiplied by the molar mass constant, The precision to which a molar mass is known depends on the precision of the atomic weights from which it was calculated. Most atomic weights are known to a precision of at least one part in ten-thousand, often much better[5] (the atomic weight of lithium is a notable, and serious,[11] exception). This is adequate for almost all normal uses in chemistry: it is more precise than most chemical analyses, and exceeds the purity of most laboratory reagents. The precision of atomics weights, and hence of molar masses, is limited by the knowledge of the isotopic distribution of the element. If a more accurate value of the molar mass is required, it is necessary to determine the isotopic distribution of the sample in question, which may be different from the standard distribution used to calculate the standard atomic weight. The isotopic di
