1. Write & Balance the chemical equation.
2. Change grams of A to moles of A.
3. Change moles of A to moles of B. [Use molar ratio: Coeffients in the equation]
4. Change moles of B to grams of B.
|
Writing &
Balancing Chemical Equations
and Mass-Mass Problems |
| Steps: 1. Write the equation correctly. This means writing all the formulas correct using subscripts. 2. Balance the equation. Use coefficients. The # of atoms on the reactant side should equal the number of atoms on the product side. 3. To balance an equation is just TRIAL & ERROR. Work it until it is balanced. |
| Identify the types of reaction: |
| Synthesis: |
A + B ---> C |
| 2K + Br2 --->
2KBr |
|
| 3Pt + 2As ---> Pt
3As2 |
|
| Decomposition: |
C ---> A + B |
| MgF2 ---> Mg +
F2 |
|
| PdCO3 ---> PdO +
CO2 |
|
| Single Replacement: |
AB + C ---> AC
+ B |
| 2Li3P + 3I2
---> 6LiI + 2P |
AB + D ---> DB
+ A |
| 2CoTe + Sn ---> SnTe
2 + 2Co |
|
| Double Replacement: |
AB + DC ---> AC
+ DB |
| SrCl2 + ZnF2
---> SrF2 + ZnCl2 |
|
| 2Rb3PO4 + Cr
2(SO4)3 ---> 3Rb2
SO 4 + 2CrPO4 |
| Identify & Balance: |
| GeBr4 + F2 --->
GeF4 + Br2 |
| Hg + Se ---> HgSe |
| K3N ---> K +
N 2 |
| Sb3(BO3)5 +
Pd(ClO3)2 ---> Sb(ClO3
)5 + Pd3(BO3)2 |
| Answers: |
|
| GeBr4 +
2F2 ---> GeF4 +
2Br2 |
Single Replacement |
| Hg + Se ---> HgSe |
Synthesis |
| 2K3
N ---> 6K +
N 2 |
Decomposition |
| 2Sb3
(BO3)5 + 15
Pd(ClO3)2 --->
6Sb(ClO3)5 +
5Pd3(BO3)2 |
Double Replacement
|
| Write the
correct balanced equation: |
| Gold + Oxygen
---> |
| Iron Sulfide +
Sodium Bromate ---> |
| Copper Phosphide --->
|
| Gallium Nitrate
+ Bismuth ---> |
| Aluminum + Bromine
---> |
| Ammonia ---> |
| Nickel Arsenate +
Potassium Sulfite ---> |
| Lead Phosphide +
Oxygen ---> |
| Answers: |
| Gold + Oxygen
---> |
| 4Au + O
2 ---> 2Au2O |
| Iron Sulfide +
Sodium Bromate ---> |
| Fe2S3
+ 6NaBrO3 ---> 2Fe(BrO3
)3 + 3Na2S |
| Copper Phosphide --->
|
| Cu3P --->
3Cu + P |
| Gallium Nitrate +
Bismuth ---> |
| 5Ga(NO3)
3 + 3Bi ---> 3Bi(NO3)
5 + 5Ga |
| Aluminum + Bromine
---> |
| 2Al + 3Br
2 ---> 2AlBr3 |
| Ammonia ---> |
| 2NH3
---> 3H2 + N2 |
| Nickel Arsenate +
Potassium Sulfite ---> |
| Ni3(AsO
4 )2 + 3K2SO3
---> 3NiSO3 + 2K3AsO4
|
| Lead Phosphide +
Oxygen ---> |
| Pb3P4
+ 3O2 ---> 3PbO2
+ 4P |
|
Mass-Mass Problems
|
| Steps: 1. Write & Balance the chemical equation. 2. Change grams of A to moles of A. 3. Change moles of A to moles of B. [Use molar ratio: Coeffients in the equation] 4. Change moles of B to grams of B. |
| Example: |
|
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