Characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices: (1) 3.0 moles of CO has a greater mass, in grams, than does 2.0 moles of CO₂.
(2) In a balanced chemical equation, there must be the same total number of molecules on each side of the equation.
(3) The molar mass and formula mass for a compound have different units but the same numerical value.

Question

Quizplus · Accepted Answer

1) FALSE. The molar mass of CO (carbon monoxide) is 28.01 g/mol, so 3.0 moles would have a mass of 84.03 grams. The molar mass of COS (carbonyl sulfide) is higher due to the presence of sulfur, so 2.0 moles would have a mass greater than 84.03 grams, making the statement false.2) FALSE. A balanced chemical equation must have the same number of each type of atom on both sides, not necessarily the same total number of molecules.3) TRUE. The molar mass is the mass of one mole of a substance and is expressed in grams per mole (g/mol), while the formula mass is the sum of the atomic masses of all atoms in a formula unit of a compound, expressed in atomic mass units (amu). Both have the same numerical value but different units.

Characterize EACH of the Three Given Statements as Being TRUE