Final answer:
To find the number of molecules of NH3 in 32 grams, we calculate the number of moles using the molar mass and then convert moles to molecules using Avogadro's number, resulting in approximately 1.132 × 10²´ molecules.
Step-by-step explanation:
To calculate how many molecules of NH3 are in 32 grams, we need to use the molar mass of NH3 and Avogadro's number. The molar mass of NH3 (14.01 g for nitrogen + 3 x 1.01 g for hydrogen) is 17.03 g/mol. Using this information, we can find the number of moles in 32 grams of NH3:
32 grams NH3 × (1 mol NH3 / 17.03 g NH3) = 1.879 moles NH3
Now, we use Avogadro's number (6.022 × 10²³ molecules/mol) to find the total number of molecules:
1.879 moles NH3 × (6.022 × 10²³ molecules/mol) ≈ 1.132 × 10²´ molecules of NH3
There are thus approximately 1.132 × 10²´ molecules of NH3 in 32 grams of NH3.