Law of constant composition

(a) State the following laws of chemical combination: (i) Law of constant composition (ii) Law of multiple’ proportion.

(b) Copper reacts with oxygen to form two oxides X and Y. On analysis, 1.535 g of X yielded 1.365 g copper and 1.450 g of Y yielded 1.160 g of cooper.

i) Determine the chemical formula of X and Y.

(ii) Calculate the mass of copper which can react with 0.500 g of oxygen to yield I. X  II. Y.

(iii) Which of the laws of chemical combination is illustrated by the result in (b)(i) above. [ = 16, Cu = 63.51


(c) Write the structure of the product responsible for the observation in each of the following reactions:

(i) A mixture of butanoic acid and ethanol warmed in the presence of concentrated H(_2)SO(_4) gives off a fragrant odour.

(ii) Sodium dissolves in propan-2-ol with effervescence to give a solution which on evaporation to dryness leaves a white precipitate.


(d) Consider the compound CH(_3)CH(_2)COOCH(_2)CH(_3).

(i) Name the compound (ii) Write the structural formula of the compound (iii) State the reagents and conditions for the formation of the compound.