State the law of multiple proportions.

State the law of reciprocal proportions.

Water and sulphur dioxide contain $88.9\% \mathrm{and} 50\%$oxygen respectively. Hydrogen sulphide contains $94.1\%$ sulphur. Show that these figures are in agreement with the law-of reciprocal proportions.

State and explain the law of multiple proportions.

$1.5$ grams of each of the two oxides of an element on reduction produced $1.331$ grams and $1.196$grams of the elements respectively. Show that the results are in agreement with the law of multiple proportions.
 

State and explain the law of conservation of mass.

$6.3$ grams of sodium bicarbonate are added to $15.0$ grams of acetic acid solution and the residue is found to weigh 18.0 grams. What mass of carbon dioxide is released during the reaction?

[Hint: ${\mathrm{NaHCO}}_3 +{\mathrm{CH}}_3\mathrm{COOH}\to {\mathrm{CH}}_3\mathrm{COONa} +{\mathrm{H}}_2\mathrm{O}+{\mathrm{CO}}_2$. In the reaction, the mass of the residue = mass of ${\mathrm{CH}}_3\mathrm{COONa}$ + mass of ${\mathrm{H}}_2\mathrm{O}$]