An organic compound contains 69% carbon and 4.8% hydrogen, the remainder being oxygen. Calculate the masses of carbon dioxide and water produced when 0.20 g of this substance is subjected to complete combustion.

Explanation

Percentage of C in an organic compound is given by
`% C =(12)/(44) xx ("Mass of "CO_2" formed")/("Mass of compound taken") xx 100`
Substituting the values, we have
`69 =(12)/( 44 ) xx (" Mass of "CO_2" formed")/( 0.2 ) xx 100`
` therefore ` Mass of `CO_2` formed = `(69 xx 44 xx 0.2 )/( 12 xx 100 ) = 0.506 g`
Similarly,
` %H =(2)/(18 ) xx (" Mass of "H_2 O " formed ")/("Mass of compound taken ") xx 100 `
Substituting the values, we have
` 4.8 = (2)/(18) xx (" Mass of "H_2 O "formed ")/(0.2 ) xx 100`
` therefore ` Mass of `H_2 O` formed =`(4.8 xx 18 xx 0.2 )/( 2 xx 100 ) = 0.0864 g `