Question

How many molecules of NH3 are produced from 8.01x10-4g of H2

Answer 1

1.61 x 10²⁰ molecules

Step-by-step explanation:

Given parameters:

Mass of the hydrogen gas = 8.01 x 10⁻⁴g

Unknown

Number of molecules of NH₃ = ?

Solution:

Given reaction:

N₂ + 3H₂ → 2NH₃

We have to solve from the known to the unknown

• The known specie is the mass of H₂ ;

find the number of moles of the specie;

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

Molar mass of H₂ = 2(1) = 2g/mol

Number of moles =
`(0.0008)/(2)` = 0.0004mol

• 3 moles of H₂ will produce 2 moles of NH₃

0.0004 moles of H₂ will produce
`(0.0004 x 2)/(3)` = 0.00027moles of NH₃

1 mole of a substance contains 6.02 x 10²³ molecules

0.00027mole of NH₃ will contain 0.00027 x 6.02 x 10²³

= 1.61 x 10²⁰ molecules