Is mass conserved when 10 g of sodium hydroxide undergoes a chemical change during an interaction with 57 g of copper sulfate? Use complete sentences to support your answer by explaining how this can be demonstrated.

The answer is yes. Mass is conserved when any matters undergo a chemical change and this law is extremely important to make algebraic calculations in chemistry.

In this case, the reaction betwee the two reactants is represented by the equation:

2NaOH + CuSO4 - - - > Na2SO4 + Cu (OH) 2

If you convert the mass of each reactant into number of moles you get:

NaOH: mass in grams / molar mass = 10 g / 40,0 g/mol = 0.25 mol

CuSO4: mass in grams / molar mass = 57 g / 159,6 g/mol = 0,357

When you use the theoretical molar ratio you can find the limitan reactant:

0.357 mol CuSO4 / 0.25 mol NaOH > 1 mol CuSO4 / 2 mol NaOH, so the 0.25 moles of NaOH will have reacted completely with 0.125 moles of CuSO4 and some CuSO4 will remain without reacting.

To prove that the mass is conserved you have to measure the masses of the products formed and add the masses of the reactants that did not react. When you compare the masses of the original compounds with the mass of the final compounds in solution you will then conclude that the mass is conserved.