Question

How many molecules of N2O5 are there in 175 grams of N2O5?

Answer 1

9.76 x 10²³molecules

Step-by-step explanation:

Given parameters:

Mass of N₂O₅ = 175gram

Unknown:

Number of molecules = ?

Solution:

To find the number of molecules contained in the given mass, we need to find the number of moles of N₂O₅ first.

Number of moles =
`(mass)/(molar mass)`

Molar mass of N₂O₅ = 2(14) + 5(16) = 108g/mol

Number of moles =
`(175)/(108)` = 1.62moles

Now;

1 mole of a substance = 6.02 x 10²³ molecules

1.62 mole of N₂O₅ = 1.62 x 6.02 x 10²³ = 9.76 x 10²³molecules