<p>A gaseous alkane&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>C</mi><mi>n</mi></msub><msub><mi>H</mi><mrow><mn>2</mn><mi>n</mi><mo>+</mo><mn>2</mn></mrow></msub></math>&nbsp;an explosion with&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>O</mi><mn>2</mn></msub></math>&nbsp;gives&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mi>C</mi><msub><mi>O</mi><mn>2</mn></msub></math>. The volume of&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>O</mi><mn>2</mn></msub></math>&nbsp;required for complete combustion of alkane to&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mi>C</mi><msub><mi>O</mi><mn>2</mn></msub></math>&nbsp;formed is 7 : 4. The value of n is........</p>