THE “LAW OF CONSERVATION OF MASS” REQUIRES IT SO THAT NO ATOMS ARE GAINED OR LOST DURING A CHEMICAL REACTION!
STEP ONE IN WORKING WITH ANY CHEMICAL EQUATION IS TO BE SURE IT IS BALANCED!!
WHAT DO THE COEFFICIENTS IN BALANCED EQUATIONS REPRESENT?
THE COEFFICIENTS OF THE REACTANTS SHOW HOW MANY MOLECULES ARE REACTING AND THE COEFFICIENTS OF THE PRODUCTS SHOW HOW MANY MOLECULES ARE FORMED.
THE EXPERIMENT WE WILL DO TODAY WILL SHOW HOW WE CAN DETERMINE THE NUMBER OF MOLECULES WHICH REACT AND THE NUMBER OF MOLECULES WHICH ARE FORMED IN A REACTION
IN OUR EXPERIMENT, WE WILL REACT IRON WITH COPPER II SULFATE PENTAHYDRATE.
IN THIS EXPERIMENT YOU WILL BE REQUIRED TO CALCULATE THE NUMBER OF MOLES OF SUBSTANCES USED. DO YOU REMEMBER HOW TO CALCULATE MOLES FROM GRAMS?
MOLES = GRAMS OF SUBSTANCE / MOLAR MASS *
*MOLAR MASS IS DETERMINED FROM THE PERIODIC TABLE.
WHAT IS THE MOLAR MASS OF IRON?
DID YOU SAY 55.8 GRAMS PER MOLE?
WHAT IS THE MOLAR MASS OF COPPER?
DID YOU SAY 63.5 GRAMS PER MOLE?
YOU SHOULD HAVE!!!
Experimental Procedures: STEP 1: Weigh a clean, dry beaker and set the balance 25.00 grams ahead. Carefully add copper II sulfate pentahydrate until the balance just balances.
Experimental Procedure: STEP 2: Add 100 ml of distilled water and stir until the copper sulfate is completely dissolved.
Experimental procedure: STEP 3 – Weigh a clean, dry beaker and set the balance 5.00 grams ahead. Carefully add iron filings until the balance just balances. You now have 5.00 grams of Fe.
Experimental Procedure: STEP 4 – Add the iron filings to the copper sulfate solution and stir. Place the mixture on low heat for 5 to 10 minutes. Notice the magnetic properties of the iron.
Experimental Procedure: STEP 5: Carefully pour the liquid through a weighed filter paper while leaving as much as the solid as possible in the bottom of the beaker. Wash the solid with distilled water and pour the wash water through the filter paper. When the filtering is complete, place the filter paper in the beaker with the solid and dry over night in an oven.
Experimental Procedure: STEP 6 – The next day remove the beaker and contents from the oven and weigh it. Notice that no magnetic properties remain when it is tested. MAGNETIC PROPERTIES HAVE DISAPPEARED !