1) A candle is placed on one pan of a balance, and a equal weight is placed on the other pan. What would happen if you lit up the candle and waited for a while?
Nothing because with the law of conservation of mass any chemical reaction makes the mass stay the same.
2) Nothing would happen if you just let a candle burn in a jar and balanced the two with a weight.
Gizmo warmup:
1) the equation H2+O2 -> H2O
A. there are 2 hydrogen atoms on the reactants and products side.
B. There are 2 oxygen atoms on the reactants side and one on the products side.
2) Right now this equation is not balanced.
Activity A:
1. Observe
A) The subscript of 2 in H2 is the number of atoms of hydrogen.
B) A subscript will always tell you the number of atoms of the element
C) Yes, because even though the number changes the subscript still tells you
the number of atoms
2. Count: formula= "Ca(OH)2"
A) # of atoms: Ca: 1 O: 2 H: 2
B) When a subscript is outside of the parenthesis is tells the number of atoms
of ALL the elements in the parenthesis.
C) Yes, because even though the amount of atoms change, the subscript still
tells the number of all of the atoms in the parenthesis, just like I said above.
3. Practice: # of atoms
A) AgCl3Cu2= Ag: 1 Cl: 3 Cu: 2
B) Ba(AsO4)2= Ba: 1 As: 2 O: 8
C) (NH4)3PO4= N: 3 H: 12 P: 1 O: 4
D) MnPb8(Si2O7)3=Mn: 1 Pb: 8 Si: 6 O: 21
Activity B:
1. Observe: H2+O2 -> H2O
As the equation is written, oxygen is not in balance because there is not the
same number of oxygen in both sides of the equation.
2. Balance
A) Add 2 infront of H2O, and now there are 2 oxygen atoms but 4 hydrogen
B) If you add 2 in front of H2 then there are 4 hydrogen atoms
C) Now this equation is balanced
3. Apply: Ca(OH)2+HBr -> CaBr2+H2O
Reactants: Products:
Ca: 1 Ca: 1
O: 2 O: 1
H: 3 H: 2
Br: 1 Br: 2
A) The hydrogen and Bromine elements are out of balance
B) Balanced equation: Ca(OH)2+2HBr -> CaBr2+2H2O
Nothing because with the law of conservation of mass any chemical reaction makes the mass stay the same.
2) Nothing would happen if you just let a candle burn in a jar and balanced the two with a weight.
Gizmo warmup:
1) the equation H2+O2 -> H2O
A. there are 2 hydrogen atoms on the reactants and products side.
B. There are 2 oxygen atoms on the reactants side and one on the products side.
2) Right now this equation is not balanced.
Activity A:
1. Observe
A) The subscript of 2 in H2 is the number of atoms of hydrogen.
B) A subscript will always tell you the number of atoms of the element
C) Yes, because even though the number changes the subscript still tells you
the number of atoms
2. Count: formula= "Ca(OH)2"
A) # of atoms: Ca: 1 O: 2 H: 2
B) When a subscript is outside of the parenthesis is tells the number of atoms
of ALL the elements in the parenthesis.
C) Yes, because even though the amount of atoms change, the subscript still
tells the number of all of the atoms in the parenthesis, just like I said above.
3. Practice: # of atoms
A) AgCl3Cu2= Ag: 1 Cl: 3 Cu: 2
B) Ba(AsO4)2= Ba: 1 As: 2 O: 8
C) (NH4)3PO4= N: 3 H: 12 P: 1 O: 4
D) MnPb8(Si2O7)3=Mn: 1 Pb: 8 Si: 6 O: 21
Activity B:
1. Observe: H2+O2 -> H2O
As the equation is written, oxygen is not in balance because there is not the
same number of oxygen in both sides of the equation.
2. Balance
A) Add 2 infront of H2O, and now there are 2 oxygen atoms but 4 hydrogen
B) If you add 2 in front of H2 then there are 4 hydrogen atoms
C) Now this equation is balanced
3. Apply: Ca(OH)2+HBr -> CaBr2+H2O
Reactants: Products:
Ca: 1 Ca: 1
O: 2 O: 1
H: 3 H: 2
Br: 1 Br: 2
A) The hydrogen and Bromine elements are out of balance
B) Balanced equation: Ca(OH)2+2HBr -> CaBr2+2H2O