Question

Sulfur trioxide can react with atmospheric water vapor to form sulfuric acid that falls as acid rain. Calculate the mass in grams of 3.65 × 1020 molecules of SO3.

Answer 1

Answer: The mass of sulfur trixoide is 0.0485 g

Explanation:

We are given:

Molecules of sulfur trixoide = $3.65\times 10^{20}$

According to mole concept:

$6.022\times 10^{23}$ number of molecules are present in 1 mole of a compound

So, $3.65\times 10^{20}$ number of molecules will be present in = $\frac{1}{6.022\times 10^{23}}\times 3.65\times 10^{20}=6.06\times 10^{-4}mol$

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Moles of sulfur trixoide = $6.06\times 10^{-4}mol$

Molar mass of sulfur trioxide = 80 g/mol

Putting values in above equation, we get:

$6.06\times 10^{-4}mol=\frac{\text{Mass of }SO_3}{80g/mol}\\\\\text{Mass of }SO_3=(6.06\times 10^{-4}mol\times 80g/mol)=0.0485g$

Hence, the mass of sulfur trixoide is 0.0485 g