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The bolume of nitrogen gas v_(m) (measured at S.T.P.) required to cover a sample of silica gel with a mono-molecular layer is 129 cm ^(3) g^(-1) of gel. Calculate the surface area per gram of the gel if each nitrogen molecule occupies 16.2xx10^(-20)m^(2). |
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Answer» Solution :`22400cm^(3)` or `N_(2)` at S.T.P. CONTAIN `=6.022xx10^(23)` molecules `THEREFORE 129 cm ^(3)` of `N_(2)` at S.T.P. will contain `=(6.022xx10^(23)xx129)/(22400)=3.468xx10^(21)` molecules Area occupied by a single molecule `=16.2xx10^(-20)m^(2)` `therefore` Area occupied by `6.468 xx10^(21)` molecules of `N_(2)=(16.2 xx10^(-20))XX(3.468xx10^(21))m^(2)=561.8m^(2)` `therefore` Surface area per gram of gel `=561.8m^(2).` |
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