When converting percent composition data into an empirical formula
CHEMISTRY · Single correct · A Level · Chemistry · Amount of substance · Amount of substance
Problem
When converting percent composition data into an empirical formula, chemists often begin by assuming that the sample has a mass of exactly 100g. Which of the following most accurately explains why this assumption is valid?
(a) Because most laboratory balances are calibrated to give their greatest precision near 100g, so choosing that mass minimizes measurement error
(b) Because selecting a 100g basis guarantees that the numbers of moles of each element will come out to whole numbers
(c) Because percent values represent parts per hundred, adopting a 100g basis allows each percent to correspond numerically to grams without altering the elemental ratios
(d) Because percent composition is only meaningful for a 100g sample; any other sample size would change the reported percentages