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Calculate the normality of 20 volume hydrogen peroxide solution. |
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Answer» Solution :Step 1. To calculate the STRENGTH in g/l of 20 VOLUME `H_(2)O_(2)` solution. By definition, 1 litre of 20 volume `H_(2)O_(2)` solution on decomposition gives 20 litres of oxygen at N.T.P. Consider the chemical equation, `underset(2xx34=68 g)(2H_(2)O_(2)) to 2H_(2)O + underset(22.4 " Litres at N.T.P.")(O_(2))` Now 22.4 litres of `O_(2)` at N.T.P. will be obtained from `H_(2)O_(2)` =68 g `therefore `20 litres of `O_(2)` at N.T.P. will be obtained from `H_(2)O_(2)=(68xx20)/(22.4)=60.7 g` Thus, the strength of 20 volume of ` H_(2)O_(2)` solution =60.7 g/l Step 2. To calculate the equivalent weight of `H_(2)O_(2)`. Consider the chemical equation `underset(68 "parts of weight")(2H_(2)O_(2))to 2H_(2)O + underset("32 parts by weight")(O_(2))` From the above equation, 32 parts by wt. of oxygen are obtained from 68 parts by wt. of `H_(2)O_(2)`. `therefore ` 8 parts by wt. of oxygen will be obtained from `(68)/(32)xx8=17` parts by wt. of `H_(2)O_(2) therefore ` EQ. wt. of `H_(2)O_(2)=17` Step 3. To calculate the normality of 20 volume `H_(2)O_(2)` solution. Now we know that , Normality =`("Strength")/(Eq. wt.)=(60.7)/(17)=3.57` Hence , the normality of 20 volume `H_(2)O_(2)` solution =3.57 N |
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