2. Atoms & Elements

Mole Concept

Open Question
Calculate the mass of 25,000 molecules of nitrogen gas. (1 mole = 6.02 x 10²³ molecules)
Open Question
How many moles of magnesium, mg, contain 9.31 × 10²² atoms of magnesium?
Open Question
One atom of gold weighs 3.27 x 10^-13 ng. how many gold atoms are in 1.0 g of gold?
Open Question
A rigid vessel contains 2.5 mol of H₂(g). How many grams of hydrogen are in the vessel?
Open Question
How many atoms are present in 0.375 mol of palladium (Pd) atoms?
Open Question
One mole of copper(II) sulfate, CuSO₄, contains ________ moles of O.
Open Question
What is the mass in grams of 0.375 mol of the element potassium, K?
Multiple Choice
How many molecules are there in 560g of silicon dioxide (SiO2)?
Multiple Choice
A compound containing only carbon and hydrogen has a carbon-to-hydrogen mass ratio of 11.89. Which of the following carbon-to-hydrogen mass ratios is possible for another compound composed only of carbon and hydrogen?
Multiple Choice
A solution is prepared by dissolving 20.2 mL of methanol (CH3OH) in 100.0 mL of water at 25°C. The final volume of the solution is 118 mL. The densities of methanol and water at this temperature are 0.782 g/mL and 1.00 g/mL, respectively. For this solution, what is the concentration of methanol in terms of molarity?
Multiple Choice
How many carbon atoms are present in 0.174 moles of carbon?
Multiple Choice
How can you convert the mass of a substance to moles?
Multiple Choice
How many aluminum atoms are there in 3.50 grams of Al₂O₃?
Multiple Choice
How many atoms are in 4.78 moles of sulfur?
Multiple Choice
How many formula units are in 8.38 g of LiOH?