Zinc sulfate crystals contain $22.65\%$ of zinc and $43.9\%$ of water. If it follows the law of definite proportions,how many grams of $Zn$ are required to obtain $20 \, g$ of crystals?

$1.7 \, g$ of silver nitrate is dissolved in $100 \, g$ of water. Another $0.585 \, g$ of sodium chloride is dissolved in $100 \, g$ of water and added to the first solution,resulting in a chemical reaction. $1.435 \, g$ of silver chloride and $0.85 \, g$ of sodium nitrate are produced. Which law is followed by the above information?

Black oxide of copper and red oxide of copper contain $79.9\%$ and $88.8\%$ of metal respectively. This data illustrates the law of:

The statement related to the law of definite proportions is:

After a chemical reaction,the total mass of reactants and products

Which of the following pairs of substances illustrates the Law of Multiple Proportions?