Question

Calculate the number of water molecules formed of 0.562 moles of oxygen gas in

2 H2 (g) + 1 O2 (g) ⟶ 2 H2O (g)

Answer 1

Answer:

6.77 · 10²³ molecules H₂O

Explanation:

Step 1: Define

2H₂ (g) + O₂ (g) → 2H₂O (g)

0.562 mol O₂

Step 2: Use Stoichiometry

$0.562 \hspace{3} mol \hspace{3} O_2(\frac{2 \hspace{3} mol \hspace{3} H_2O}{1 \hspace{3} mol \hspace{3} O_2} )$ = 1.124 mol H₂O

$1.124 \hspace{3} mol \hspace{3} H_2O(\frac{6.02(10)^{23} \hspace{3} molecules \hspace{3} H_2O}{1 \hspace{3} mol \hspace{3} H_2O} )$ = 6.76648 · 10²³ molecules H₂O

Step 3: Simplify

We have 3 sig figs.

6.76648 · 10²³ molecules H₂O ≈ 6.77 · 10²³ molecules H₂O