Atomic Mass and Gaseous Elements

The video tutorial introduces the concept of the mole in chemistry, explaining its historical development and foundational ideas such as relative and atomic mass. It covers the contributions of scientists like J. Gusak, Avogadro, and Dalton. The tutorial explains how relative mass is a comparison of masses, initially using hydrogen as a reference. It also discusses the transition to using oxygen and carbon-12 for atomic mass comparisons. The video provides detailed examples of calculating molecular mass, emphasizing the importance of understanding chemical formulas and atomic mass units.

What did J. Gusak discover about gaseous elements?

• They combine in random ratios.

• They combine in simple whole number ratios by volume.

• They do not combine at all.

• They combine in complex ratios.

What is Avogadro's hypothesis about gases?

• Equal volumes of gases at the same temperature and pressure contain equal numbers of particles.

• Gases do not have particles.

• Different gases have different numbers of particles.

• Gases have the same mass.

Why was hydrogen initially used as a reference for atomic mass?

• It is the heaviest element.

• It is the most abundant element.

• It is the most reactive element.

• It was the lightest known element at the time.

Why are atomic masses on the periodic table not whole numbers?

• They are averages of all isotopes of an element.

• They are rounded to the nearest whole number.

• They are estimated values.

• They are measured in grams.

What is the modern standard for comparing atomic masses?

• Nitrogen

• Hydrogen

• Oxygen

• Carbon-12

What is the atomic mass unit (AMU) based on?

• 1/12th the mass of a carbon-12 atom

• The mass of a hydrogen atom

• The mass of an oxygen atom

• The mass of a nitrogen atom

How many atomic mass units does one magnesium atom weigh?

• 1.01

• 16.00

• 24.31

• 12.01

In the example of copper acetate, how many carbon atoms are present?

• Two

• Four

• Six

• Eight

What is the total atomic mass of a molecule of C6H6O6?

• 96 AMU

• 174.12 AMU

• 72.06 AMU

• 12.01 AMU

What is the atomic mass of sulfur in copper sulfate?

• 63.55 AMU

• 16.00 AMU

• 32.06 AMU

• 1.01 AMU