Choose all of the chemical reactions which correctly show that chemical reactions must obey the Law of Conservation of Matter.
a. CH4 + 2O2 → CO2 + H2O
b. H2 + O2 → H2O ***
c. C6H12O6 + 6O2 → 6CO2 + 6H2O
d. 2CO + O2 → 2CO2 ***
e. 4P + O2 P4O10
(b) what happened to the other O?
(c) ?
To determine which chemical reactions correctly show that chemical reactions must obey the Law of Conservation of Matter, we need to check if the number of atoms of each element is the same on both sides of the chemical equation.
a. CH4 + 2O2 → CO2 + H2O
To balance this equation, we need 2 CO2 molecules and 2 H2O molecules on the right side. The balanced equation is:
CH4 + 2O2 → CO2 + 2H2O
b. H2 + O2 → H2O
This equation is already balanced. The number of hydrogen and oxygen atoms is the same on both sides.
c. C6H12O6 + 6O2 → 6CO2 + 6H2O
This equation is already balanced. The number of carbon, hydrogen, and oxygen atoms is the same on both sides.
d. 2CO + O2 → 2CO2
This equation is already balanced. The number of carbon and oxygen atoms is the same on both sides.
e. 4P + O2 → P4O10
To balance this equation, we need 5 O2 molecules on the left side and 2 P4O10 molecules on the right side. The balanced equation is:
5O2 + 4P → 2P4O10
Based on the analysis above, the chemical reactions that correctly show that chemical reactions must obey the Law of Conservation of Matter are:
b. H2 + O2 → H2O
d. 2CO + O2 → 2CO2