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a) 56 ml

b) 560 ml

c) 11.2 ml

d) 2.24 ml

Answer

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Morality = $\frac{{{\text{ Number of moles}}}}{{{\text{Volume(L) }}}}$

${\text{2}}{{\text{H}}_2}{{\text{O}}_2} \to 2{{\text{H}}_2}{\text{O + }}{{\text{O}}_2}$

From the above reaction, we can conclude that in general, 2 moles ${{\text{H}}_2}{{\text{O}}_2}$ yield 1 mole of ${\text{ }}{{\text{O}}_2}$

Therefore, 1 mole ${{\text{H}}_2}{{\text{O}}_2}$ will yield $\frac{1}{2}$ moles of ${\text{ }}{{\text{O}}_2}$

But, to find out how many moles of ${{\text{H}}_2}{{\text{O}}_2}$ is formed in the given conditions of our question, we will use the formula for molarity to calculate the same,

Morality = $\frac{{{\text{ Number of moles}}}}{{{\text{Volume(L) }}}}$

$ \Rightarrow {\text{Number of moles = Molarity}} \times {\text{Volume(L)}}$

We are given two values i.e., molarity and volume but the given volume is in ml we have to convert it to liter (L) by dividing it by 1000 (since 1ml = $\frac{1}{{1000}}$L). Therefore 20ml = $\frac{1}{{1000}}$$ \times $ 20 L.

Now putting up all the values in the mentioned formula, we will calculate the number of moles of ${{\text{H}}_2}{{\text{O}}_2}$

$ \Rightarrow {\text{Number of moles = }}$ $2.5 \times \frac{1}{{1000}} \times 20$

$ \Rightarrow {\text{Number of moles = }}$$0.05$

Therefore, for the given conditions in our question 0.05 moles of ${{\text{H}}_2}{{\text{O}}_2}$ will form,

Now we will find out how many moles of ${\text{ }}{{\text{O}}_2}$ will be yielded by 0.05 moles of ${{\text{H}}_2}{{\text{O}}_2}$

$ \Rightarrow {\text{Number of moles of }}{{\text{O}}_2}{\text{ = }}\frac{1}{2} \times 0.05$

= $0.025$ moles of ${\text{ }}{{\text{O}}_2}$

We know that 1 mole of any atom has = 22.4 L of volumes.

Therefore, 0.025 moles of ${\text{ }}{{\text{O}}_2}$ has volume

$ \Rightarrow $ $22.4 \times 0.025$ = $0.056{\text{ L}}$

As most of the options are given in ml we will have to convert 0.56 L in ml to check if it matches with any given answer,

$ \Rightarrow $$0.056{\text{ L}}$ = $0.056 \times 1000$ =$560{\text{ ml}}$

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