CONSERVATION OF MATTER OBJECTIVE: Observe and learn the law.

QUESTION How is the law of conservation proven during physical and chemical change?

RESEARCH Law of conservation of matter: “Matter can neither be created nor destroyed.” The mass (g) of the reactants always equals the mass (g) of the products in a reaction. A.K.A. Law of conservation of MASS

Precipitate: (ppt.) A solid crystallizes in a solution.

HYPOTHESIS: The combined mass of salt and water will remain the same/change when they are mixed. The masses of the two liquids, when combined, will/will not equal the sum of the masses of the two liquids before being combined.

EXPERIMENT Zero the balance. PART A Physical Change: dissolving Zero the balance. Add 50 ml of water to a beaker. Put a small amount of salt on the watchglass. Find the mass of the beaker/water and the watchglass/salt AT THE SAME TIME. Without spilling, mix the salt into the water and swirl until the salt dissolves. Find the mass of the salt water, beaker, and watchglass together. Record this mass below.

EXPERIMENT Clean the beaker from Part A. PART B Chemical Change: precipitate Clean the beaker from Part A. Add 25 ml of water each to two beakers. Add a small amount of Na2CO3 to one of the beakers and swirl until dissolved. Add a small amount of MgSO4 to the other beaker and swirl until dissolved.

EXPERIMENT Find the mass of each beaker and add to get a total of the beakers together. Record the total mass “MASS OF SEPARATE BEAKERS (SOLUTIONS)” Pour the MgSO4 carefully into the beaker of Na2CO3. Find the mass of the new mixture (be sure to add the mass of the empty beaker).

PART B: THE PRECIPITATE REACTION Please write this on the bottom of your page after your conclusions. PART B: THE PRECIPITATE REACTION Na2CO3 + MgSO4 --- Na2SO4 + MgCO3 (ppt) REACTANTS --- PRODUCTS DOUBLE REPLACEMENT REACTION

CONCLUSIONS What happened to the salt in Part A? It dissolves. What happened when the two solutions from Part B were combined? Precipitate formed. ¾: Record the masses from your data. Matter was/was not conserved: it was. What could account for any difference between the masses of the solutions separate and the combined mixture mass? Spilling; misuse of the balance.

Predict the mass of 100 ml solution of Kool Aid if it has the following data: mass of Kool Aid solution: 104 g.