No,they just separate away from each other
Actually mass and weight are two different things but most people did not understand the difference between them. And they are used synonymously on the earth. Mass is the measure of the amount of matter and weight is the measure of how the force of gravity acts on the mass that is Weight = mass x force of gravity. And they are also directly proportional to each other that is also the reason both terms are used synonymously.
Answer: 2) 0.21 mole H2O
3) 0.50 mole K2O
4) 123 g Ca( NO3)2
Explanation: solution attached.
For number 2 to find the number of moles of H2O just divide the given in molecules with the Avogadro's number.
For 3 convert grams of K2O to moles by using 1 mole of K2O is equal to the molar mass of K2O
For number 4 moles to grams. Same process with number 3
Answer: percentage of the copper recovered is 88.8 %
Explanation:
Given : Initial amount of copper = 0.502 g
Recovered amount of copper = 0.446 g
percentage of copper recovered = 
Putting in the values :
percentage of copper recovered = 
Thus percentage of the copper recovered is 88.8 %