Question

What is the volume strength of 1.5 N ${{H}_{2}}{{O}_{2}}$ solution?

Answer 1

Normality of any solution is the gram equivalent of solute per liter of solution. The strength of any solution is the normality multiplied by equivalent weight. Equivalent weight is the molar mass divided by n factor. Volume strength of hydrogen peroxide is the volume of oxygen at STP divided by volume of ${{H}_{2}}{{O}_{2}}$. At NTP any gas has a volume of 22.4 L.

Complete answer:
Volume strength of ${{H}_{2}}{{O}_{2}}$ is the term that denotes ${{H}_{2}}{{O}_{2}}$ concentration in the value of the volume of oxygen that has been formed alongside water by the decomposition of hydrogen peroxide. The equation of hydrogen peroxide decomposition is: $2{{H}_{2}}{{O}_{2}}\to 2{{H}_{2}}O+{{O}_{2}}$
We have been given normality that is the concentration term of ${{H}_{2}}{{O}_{2}}$ solution as 1.5 N. Now, to determine the volume strength, we will first calculate the strength of 1.5 N ${{H}_{2}}{{O}_{2}}$, then we will calculate the amount of ${{H}_{2}}{{O}_{2}}$ through stoichiometry, and then dividing the amount of oxygen at STP by the amount of ${{H}_{2}}{{O}_{2}}$ we will get the volume strength.
Strength of 1.5 N${{H}_{2}}{{O}_{2}}$= normality$\times$ equivalent weight (${{H}_{2}}{{O}_{2}}$= 17)
Strength of 1.5 N${{H}_{2}}{{O}_{2}}$= 1.5$\times$17
Strength of 1.5 N${{H}_{2}}{{O}_{2}}$= 25.5
Now, we have through the equation, 2 moles of ${{H}_{2}}{{O}_{2}}$ produce 1 mole of ${{O}_{2}}$. As 1 mole of ${{H}_{2}}{{O}_{2}}$ has weight equal to molar mass = 34,
So mass of 2 moles of ${{H}_{2}}{{O}_{2}}$= 68 g/mol
We have 68 g/mol ${{H}_{2}}{{O}_{2}}$ producing 1 mole that is 22.4 L of oxygen gas at NTP.
So, the volume strength will be, $\dfrac{Vol\,of\,{{O}_{2}}at\,NTP}{mass\,of\,{{H}_{2}}{{O}_{2}}}\times strength\,of\,{{H}_{2}}{{O}_{2}}$
Volume strength = $\dfrac{22.4\,}{68\,}\times 25.5$
Volume strength = 8.4 L
Hence, the volume strength of 1.5 N ${{H}_{2}}{{O}_{2}}$ solution is 8.4 liter.

Note:
The n factor of any compound is the number of replaceable hydrogen atoms, as hydrogen peroxide has 2 hydrogen atoms, so its molar mass divided by 2 gives us its equivalent mass as 17. Any gas at NTP contains the same volume so the volume of oxygen gas is 22.4 L, this can also be 22.7 L.