The ratio of the mass percentages of ‘C & H’ and ‘C & O’ of a saturated acyclic organic compound ‘X’ are 4 : 1 and 3 : 4 respectively. Then, the moles of oxygen gas required for complete combustion of two moles of organic compound ‘X’ is ________.
Answer (integer)
5
Solution
Let the organic compound X is = C<sub>x</sub>H<sub>y</sub>O<sub>z</sub>
<br><br>Here moles of C = x, moles of H = y, moles of O = z
<br><br>Given, ${{{W_C}} \over {{W_H}}} = {4 \over 1}$
<br><br>$\therefore$ ${x \over y} = {{{{{W_C}} \over {12}}} \over {{{{W_H}} \over 1}}}$ = ${4 \over 1} \times {1 \over {12}}$ = ${1 \over 3}$
<br><br>Also Given, ${{{W_C}} \over {{W_O}}} = {3 \over 4}$
<br><br>$\therefore$ ${x \over z} = {{{{{W_C}} \over {12}}} \over {{{{W_O}} \over {16}}}}$ = ${3 \over 4} \times {{16} \over {12}}$ = 1
<br><br>$\Rightarrow$ x = z
<br><br>$\therefore$ Empirical formula = C<sub>x</sub>H<sub>3x</sub>O<sub>x</sub> = CH<sub>3</sub>O
<br><br>As compound is saturated acyclic organic<br> compound, so molecular formula = C<sub>2</sub>H<sub>6</sub>O<sub>2</sub>
<br><br>C<sub>2</sub>H<sub>6</sub>O<sub>2</sub> + ${5 \over 2}$O<sub>2</sub> $\to$ 2CO<sub>2</sub> + 3H<sub>2</sub>O
<br><br>For 1 mole of C<sub>2</sub>H<sub>6</sub>O<sub>2</sub> number of moles of O<sub>2</sub> required = ${5 \over 2}$
<br><br>$\therefore$ For 2 mole of C<sub>2</sub>H<sub>6</sub>O<sub>2</sub> number of moles <br>of O<sub>2</sub> required = ${5 \over 2}$ $\times$ 2 = 5
About this question
Subject: Chemistry · Chapter: Some Basic Concepts of Chemistry · Topic: Mole Concept
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