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(a) Four samples of carbon dioxide (CO(2...

(a) Four samples of carbon dioxide `(CO_(2))` were prepared by using different methods. Each sample on analysis was found to contain 27.27% carbon by mass. Name the law which is in agreement with this observation.
(b) Explain why the number of atoms in one mole of hydrogen gas is double the number of atoms in one mole of helium gas.

Text Solution

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Carbon dioxide consists of elements carbon and oxygen. Since the percentage of carbon in each sample is fixed, that of oxygen must be also fixed. This is according to law of constant proportions.
(b) Hydrogen gas is diatomic in nature `(H_(2))` while helium gas is monoatomic (He). As a result, the number of atoms in one mole of hydrogen. `(2xxN_(A))` are expected to be double as compared to number of atoms in one mole of helium `(N_(A))`.
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Knowledge Check

  • A compound (molar mass = 120 g ) contains 40% carbon by mass. If the ration of number of H and O atoms in the compound is 2 : 1, then number of H- atoms in one molecule of the compound is :-

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    2
    B
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  • Two different formulas are used in order to represent composition of any miolecule, empirical formula and molecular formula . While the fomer gives an idea of relative ratio of number of atoms, latter gives the exact number of atoms in the molecule. An organic compound contains C N and O . The number of oxygen atom is same as that of nitogen atom which is one third of number of carbon atoms and number of hydrogen atoms is approximately 2.33 times of carbon atoms. If vapour density of the compound is 73 then molecular formula of the compound will be :

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    `C_(3)H_(7)NO`
    B
    `C_(2)H_(5)NO`
    C
    `C_(6)H_(14)N_(2)O_(2)`
    D
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  • Adenine is a substituted form of a heterocyclic nitrogenous base Purine. Adenine is found in both polymers DNA and RNA . Adenine is composed of the elements carbon, hydrogen and nitrogen and has molecular mass of 13.5 amu . Upon analysis, it was found that the ratio of % (by w.t. ) of carbon to that of total % (by wt ) of hydrgoen and nitrogen was found to be 4:5 respectively. The ratio of number of N atoms to hydrogen atoms is 1 : 1 . Now, answer the following questions: In one molecule of adenine :

    A
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    B
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    C
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