Question

How many molecules in each sample?

64.7 g N2
83 g CCl4
19 g C6H12O6

Answer 1

• 1.39x10²⁴ molecules N₂

• .25x10²³ molecules CCl₄

• 6.38x10²² molecules C₆H₁₂O₆

Step-by-step explanation:

First we convert the given masses into moles, using the compounds' respective molar mass:

• 64.7 g N₂ ÷ 28 g/mol = 2.31 mol N₂

• 83 g CCl₄ ÷ 153.82 g/mol = 0.540 mol CCl₄

• 19 g C₆H₁₂O₆ ÷ 180 g/mol = 0.106 mol C₆H₁₂O₆

Then we multiply each amount by Avogadro's number, to calculate the number of molecules:

• 2.31 mol N₂ * 6.023x10²³ molecules/mol = 1.39x10²⁴ molecules

• 0.540 mol CCl₄ * 6.023x10²³ molecules/mol = 3.25x10²³ molecules

• 0.106 mol C₆H₁₂O₆ * 6.023x10²³ molecules/mol = 6.38x10²² molecules