Chemistry - Concentration Terms Question with Solution | TestHub

ChemistryConcentration TermsMiscellaneous/MixedMedium2 minQB

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The strength of an $H_{2} O_{2}$ sample is generally expressed in terms of its volume strength. This refers to the volume of oxygen liberated at N.T.P. by heating one volume of hydrogen peroxide. The concentration of $H_{2} O_{2}$ in a solution can also be expressed as a percentage of $H_{2} O_{2}$ in the solution. The normality of this solution can be calculated if the equivalent mass of $H_{2} O_{2}$ is known.

25 ml of $H_{2} O_{2}$ solution was added to the excess of acidified KI solution. The iodine so liberated required 40 ml of 0.1 N sodium thiosulphate solutions. Calculate the normality of $H_{2} O_{2}$ solution.

Options:

Answer:

Solution:

$H_{2} O_{2} + 2 KI + H_{2} SO_{4} \to K_{2} SO_{4} + I_{2} + 2 H_{2} O$

$I_{2} + Na_{2} S_{2} O_{3} \to 2 NaI + Na_{2} S_{4} O_{6}$

4 mmol of hypo means 2 mmole of $I_{2}$ and 2 mmole of $H_{2} O_{2}$ .

so molarity $= \frac{2}{25}$ , normality $= \frac{4}{25} = 0.16 N$

Stream:JEESubject:ChemistryTopic:Concentration TermsSubtopic:Miscellaneous/Mixed

⏱ 2mℹ️ Source: QB

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