View
220
Download
0
Category
Preview:
Citation preview
Law of Conservation of MassLavoisier (1743-1794)
100 g 100 gCoal is completely
burned
What do you observe?
START END
Law of Conservation of MassLavoisier (1743-1794)
In a chemical reaction, matter is neither created nor destroyed, it is transformed into something
else.
100 g 100 gCoal is completely
burnedWeight of jar & its contents remains the same. Mass is conserved
Since matter can not be created or destroyed, chemical reactions must be __________ in terms of _________.
Reactants Products
The amount of mass you start with must
equal to the mass of the products:
100g total =
100g total
balanced mass
According to the law of conservation of mass, how much zinc was present in the zinc carbonate?
A 40 g B 88 g C 104 g D 256 gREMEMBER !!!
The mass on both sides of the arrow must be equal.
+ =
256g 256g
+
ANSWER: 256- 152 = 104g of Zn
CuCO3(s) CuO(s) + CO2(g)123.6 g 79.6 g ? g44.0 g
What are the reactants? CuCO3
What are the products?
CuO & CO2
What is the mass of reactants? 123.6 g
79.6 g + CO2
What is the mass of products?
Mass?
Answer: 123.6 – 79.6 = 44.0g of CO2
According to the law of conservation of mass, how much carbon dioxide was present in the copper (II) carbonate?
123.6g
+
123.6g
For the Last Two Examples• You can set every Chemical Equation up like an
Algebraic Equation and solve it for the variable. For instance this equation,
can be written algebraically using the masses given on the previous slide like below. Now you only have to solve for x!
123.6 [g] = 79.6 [g] + x
CuCO3(s) CuO(s) + CO2(g)
Recommended