Gizmos Student Exploration: Stoichiometry Questions with Correct Answers

Vocabulary: Avogadro’s number, balanced equation, cancel, coefficient, conversion factor, dimensional analysis, molar mass, mole, molecular mass, stoichiometry Activity A: Moles Get the Gizmo ready: ● Check that the equation is still: Fe2O3 + 3CO 2Fe + 3CO2 ● If not, click New equation until it reappears. Question: How do scientists find the molecular mass and molar mass of a substance? 1. Calculate: The molecular mass of a molecule is the sum of the masses of each atom in the molecule. The unit of molecular mass is the universal mass unit (u). Iron’s atomic mass is 55.85 u, carbon’s mass is 12.01 u, and oxygen’s mass is 16.00 u. A. Calculate the molecular mass of carbon monoxide (CO) by adding the atomic mass of carbon and the atomic mass of oxygen: ______28.01g____________________ B. Calculate the molecular mass of carbon dioxide (CO2 ): ____44.01g_____________ C. Calculate the molecular mass of iron (III) oxide (Fe2O3 ): ______159.7 g_