Understanding Two-Step Conversions and Moles

This video tutorial covers two-step conversions in chemistry, focusing on converting between particles, mass, and volume. It explains the central role of the mole as a bridge between the microscopic and macroscopic worlds. The tutorial provides detailed examples, including calculating the mass of potassium phosphate and the volume of helium gas at standard temperature and pressure (STP). Key conversion factors, such as Avogadro's number and molar mass, are discussed. The video concludes with a roadmap for solving complex problems and encourages practice.

What is the central unit that connects the microscopic and macroscopic worlds in chemistry?

• Gram

• Liter

• Mole

• Particle

How many particles are there in one mole?

• 6.02 x 10^23

• 9.81 x 10^9

• 1.00 x 10^6

• 3.14 x 10^10

What is the molar mass of magnesium in grams per mole?

• 12.01 g/mol

• 24.3 g/mol

• 32.07 g/mol

• 40.08 g/mol

In the example problem, what is the mass of 1.79 x 10^24 formula units of K3PO4?

• 1000 grams

• 212 grams

• 631 grams

• 500 grams

What is the volume occupied by one mole of any gas at STP?

• 11.2 liters

• 33.6 liters

• 44.8 liters

• 22.4 liters

What does STP stand for in chemistry?

• Standard Temperature and Pressure

• Standard Temperature and Proportion

• Standard Time and Pressure

• Standard Time and Proportion

How many moles of helium gas will occupy 149.3 liters at STP?

• 10.00 moles

• 3.33 moles

• 6.665 moles

• 5.00 moles

In the final example, what is the volume of 4.32 x 10^23 atoms of krypton gas at STP?

• 10.5 liters

• 16.1 liters

• 30.0 liters

• 22.4 liters

What is the first step in converting particles to mass?

• Convert particles to volume

• Convert moles to grams

• Convert particles to moles

• Convert grams to particles

Which conversion factor is used to go from moles to volume?

• 1.00 atm

• 22.4 liters

• 0 degrees Celsius

• 6.02 x 10^23