The question is as follows: How many oxygen molecules are produced by the decomposition of 28.5 g of H2O2 (molecular mass = 34.0g / mol) according to the equation
2H2O2 (l) → 2H2O (l) + O2 (g)
Answer: There are [tex]2.52 \times 10^{23}[/tex] molecules are produced by the decomposition of 28.5 g of [tex]H_{2}O_{2}[/tex] according to the equation [tex]2H_{2}O(l) \rightarrow 2H_{2}O(l) + O_{2}(g)[/tex].
Explanation:
Given: Mass of [tex]H_{2}O_{2}[/tex] = 28.5 g
As moles is the mass of a substance divided by its molar mass. Hence, moles of [tex]H_{2}O_{2}[/tex] is calculated as follow.
[tex]Moles = \frac{mass}{molarmass}\\= \frac{28.5 g}{34.0 g/mol}\\= 0.838 mol[/tex]
According to the given equation, 2 moles of [tex]H_{2}O_{2}[/tex] gives 1 mole of [tex]O_{2}[/tex]. So, moles of [tex]O_{2}[/tex] produced by 0.838 moles of [tex]H_{2}O_{2}[/tex] will be calculated as follows.
[tex]Moles of O_{2} = \frac{0.838 mol}{2}\\= 0.419 mol[/tex]
This means that moles of [tex]O_{2}[/tex] produced is 0.419 mol.
As per the mole concept, 1 mole of every substance has [tex]6.022 \times 10^{23}[/tex] molecules.
So, molecules of [tex]O_{2}[/tex] present in 0.419 mole are as follows.
[tex]0.419 \times 6.022 \times 10^{23}\\= 2.52 \times 10^{23}[/tex]
Thus, we can conclude that there are [tex]2.52 \times 10^{23}[/tex] molecules are produced by the decomposition of 28.5 g of [tex]H_{2}O_{2}[/tex] according to the equation [tex]2H_{2}O(l) \rightarrow 2H_{2}O(l) + O_{2}(g)[/tex].