A researcher wishes to prepare 1.00 mol of carbon dioxide gas using isotopically pure…
CHEMISTRY · Multi-part · A Level · Chemistry · Amount of substance · Amount of substance
Problem
A researcher wishes to prepare 1.00 mol of carbon dioxide gas using isotopically pure reactants. The carbon atoms are all the isotope carbon-12, and the oxygen atoms are all the isotope oxygen-16. The researcher will collect the gas at low pressure so that the electrons can be considered unbound to any particular nucleus for the purpose of mass estimation.
The following constants may be useful:
• 1 u = 1.66×10−27kg
• Mass of an electron =9.11×10−31kg
(1) Calculate the approximate total mass, in kilograms, of 1.00 mol of this isotopically pure carbon dioxide sample by treating the atomic masses as exactly equal to their mass numbers.
(2) Using the same constants, determine the percent error introduced in part (a) by neglecting the combined mass of all of the electrons in the sample.
(3) Assess whether the integer-mass approximation is adequate for typical macroscopic laboratory work with gases, and support your conclusion with the quantitative result from part (b).