Question

1. how is a mole defined? (0.5 points) *

the number of ions in 20 g of aqueous sodium chloride
the number of particles in 6.022 g of pure water
the number of oxygen atoms in exactly 16 g of pure oxygen-16
the number of carbon atoms in exactly 12 g of pure carbon-12

Explanation:

To determine the correct definition of a mole, we recall the scientific definition: a mole is the amount of substance that contains as many elementary entities (such as atoms, molecules, ions, etc.) as there are atoms in exactly 12 grams of carbon - 12.

• The first option is incorrect because it refers to ions in 20 g of aqueous sodium chloride, which is not related to the standard definition of a mole.
• The second option is incorrect as it refers to particles in 6.022 g of pure water, and the mole is not defined in this way.
• The third option is incorrect because the mole is defined with respect to carbon - 12, not oxygen - 16 in this context.
• The fourth option matches the definition of a mole, which is the number of carbon atoms in exactly 12 g of pure carbon - 12.

Answer:

D. The number of carbon atoms in exactly 12 g of pure carbon - 12