Chemical Equations
The small numbers in chemical equations are called _______________.
subscripts
A ______________________ chemical reaction is when two or more substances combine to form a more complex compound.
synthesis
2HgO → 2Hg+O2(g)
Decomposition
__N2 + __H2 ---> __NH3
N2 + 3H2 ---> 2NH3
Physical changes don't actually change what something is, but chemical changes make it a new thing with new characteristics. Physical changes can be physically reversed, but chemical changes can't.
The large numbers in front of chemical equations are called ________________.
coefficients
In a _____________________ reaction, a substance combines with oxygen and light and heat are given off.
combustion
2Na+Cl2 → 2NaCl
Synthesis
__Al + __O2 ---> __Al2O3
4Al + 3O2 ---> 2Al2O3
What is a chemical reaction?
A process by which one or more substances are changed into one or more new substances with new characteristics.
A __________________ chemical reaction is when a compound divides into two or more simpler substances.
decomposition
C3H8+5O2 → 3CO2+4H2O
(light and heat are produced as well)
combusiton
__Al + __HCl ---> __AlCl3 + __H2
2Al + 6HCl ---> 2AlCl3 + 3H2
What is the oxidation number of Sulfur?
-2
The substances on the right side of a chemical equation are called ________________.
products
In a ____________________ ________________ reaction, one element replaces another in a compound.
single replacement
2KI+Pb(NO3)2 → 2KNO3+PbI2
__H3PO4 + __HCl --> __PCl5 + __H2O
H3PO4 + 5HCl --> PCl5 + 4H2O
The Law of Conservation of __________________ tells us that matter can’t be __________________ or destroyed.
Mass; created
How many total atoms are in 5(NH4)2O
55
In a _____________________ ____________________ replacement reaction, two ionic compounds change partners.
double replacement
Mg+Cu(NO3)2 → Mg(NO3)2+Cu
Single replacement
__CO + __H2 --->__C8H18 +__H2O
8CO + 17H2 ---> C8H18 + 8H2O
What is the difference between a cation and an anion?
A cation has given away electrons and become positively charged; an anion has received electrons and become negatively charged.