Mole Concept and Avogadro's Number

What is Avogadro's number?

• 6.022×10^23

• 1.602×10^−19

• 3.00×10^8

How many particles are in one mole of a substance?

• 6.022×10^23

• 1.00×10^6

• 1.00×10^3

If you have half a mole of helium (He), a noble gas, how many atoms do you have?

• 3.011×10^23

• 6.022×10^23

• 1.204×10^24

How many atoms are in one quarter of a mole of sodium (Na), a metal?

• 1.506×10^23

• 3.011×10^23

• 6.022×10^22

What is the number of atoms in one tenth of a mole of chlorine (Cl), a non-metal?

• 6.022×10^22

• 6.022×10^21

• 6.022×10^20

In the experiment, what was measured to determine the number of molecules in a drop of water (H₂O)?

• Volume of the drop

• Mass of the drop

• Temperature of the drop

If the mass of one drop of water is 0.05 g, how many moles of water are in the drop? (Molar mass of water = 18.016 g/mol)

• 2.78×10^−3 moles

• 5.55×10^−3 moles

• 1.39×10^−3 moles

How many molecules are in a drop of water with a mass of 0.05 g?

• 1.67×10^21

• 3.34×10^21

• 8.35×10^20

How many hydrogen atoms are in a drop of water with a mass of 0.05 g?

• 3.34×10^21

• 6.68×10^21

• 1.67×10^21

How many total atoms are in a drop of water with a mass of 0.05 g?

• 1.00×10^22

• 1.34×10^22

• 2.00×10^22