Multiple Choice
How many carbon atoms are present in 15.0 grams of graphite (pure carbon)? (Atomic mass of carbon = 12.01 g/mol)
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2. Atoms & Elements
Calculating Molar Mass
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What is the molar mass of magnesium (Mg) atoms?
A
12.0 g/mol
B
24.3 g/mol
C
32.1 g/mol
D
40.1 g/mol
Verified step by step guidance1
Understand that the molar mass of an element is the mass of one mole of its atoms, usually expressed in grams per mole (g/mol).
Locate magnesium (Mg) on the periodic table to find its atomic mass, which represents the molar mass of magnesium atoms.
Note that the atomic mass listed on the periodic table is typically a weighted average of all naturally occurring isotopes of magnesium.
Use the atomic mass value directly as the molar mass of magnesium, since 1 mole of Mg atoms has a mass equal to this atomic mass in grams.
Confirm that the molar mass of magnesium is approximately 24.3 g/mol, which corresponds to the atomic mass found on the periodic table.
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