2. Atoms & Elements

How many molecules are there in 560g of silicon dioxide (SiO2)?

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?

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?

How many carbon atoms are present in 0.174 moles of carbon?

How can you convert the mass of a substance to moles?

How many aluminum atoms are there in 3.50 grams of Al₂O₃?

How many atoms are in 4.78 moles of sulfur?

How many formula units are in 8.38 g of LiOH?

How many hydrogen atoms are in one formula unit of ammonium sulfate, (NH4)2SO4?

How many iron atoms are contained in 354 g of iron, given that the molar mass of iron is 55.85 g/mol?

How many molecules are in 68.6 moles of CO₂?