kemikals
Monday, March 21, 2011
CHEMICAL FORMULA WRITING AND NAMING
1 What is the chemical formula for lead (IV) cyanide?
2 What is the chemical formula for silver chlorate?
3 What is the chemical formula for zinc carbonate?
4 What is the chemical formula for cadmium fluoride?
5 What is the chemical formula for nickel (II) sulfide?
6 What is the chemical formula for calcium oxalate?
7 What is the chemical formula for barium oxide?
8 What is the chemical formula for magnesium sulfide?
9 What is the chemical formula for pentane?
10 What is the chemical formula for lithium phosphate?
Writing Chemical Formulas
1 NaClO3 is the chemical formula for what?
2 BaS2O3 is the chemical formula for what?
3 Zn(CH3COO)2 is the chemical formula for what?
4 SrC2O4 is the chemical formula for what?
5 CuCO3 is the chemical formula for what?
6 CaS is the chemical formula for what?
7 MgO is the chemical formula for what?
8 K2CrO4 is the chemical formula for what?
9 FeF2 is the chemical formula for what?
10 KCl is the chemical formula for what?
11.
N2O5
12.
Co2O3
13.
NO2
14.
NaOH
15.
HgS
16.
NH4OH
17.
NiCl2
18.
CaCO3
19.
Ba(OH)2
20.
Cs3N
21.
AgCl
22.
NiF2
23.
N2O3
24.
AuCl3
25.
CCl4
16.
NCl3
27.
PO5
28.
CCl4
29.
Cs3PO4
30.
(NH4)2SO4
balancing chemical equation
Balancing Chemical Equations
What is a chemical equation?
When a chemical reaction occurs, it can be described by an equation. This shows the chemicals that react (called the reactants) on the left-hand side, and the chemicals that they produce (called the products) on the right-hand side. The chemicals can be represented by their names or by their chemical symbols.
Unlike mathematical equations, the two sides are separated by an arrow, that indicates that the reactants form the products and not the other way round.
The concept of balancing equations
Take a look at this chemical word equation:
This is the equation for the burning of aluminium in oxygen. If we convert each of the chemical names into the appropriate symbols, we get the following:
You can see by looking at it that there is something wrong with this equation. If you count the number of atoms of each type on each side, you will see that there is only one aluminium atom on the left side whereas there are two on the right. There are two oxygen atoms on the left side, as compared to three on the right side. This clearly doesn't match.
Left side: | Right side: |
We can balance the equation by mutiplying the different atoms and molecules on each side by different amounts. Firstly, multiply the aluminium atoms on the left side by 2:
Left side: | Right side: |
Now there are the same number of aluminium atoms on each side of the equation. We could also multiply the number of oxygen molecules on each side by one and a half (1.5), which would give three oxygen atoms on the left side (1.5 x 2 = 3) to match the three oxygen atoms on the right side:
Left side: | Right side: |
This is now balanced, but that 1.5 is a horrible thing to have in an equation - how can you have one and a half molecules? We can solve this problem by multiplying everything throughout by 2:
Left side: | Right side: | |||
Write your answers in the boxes. Every box will require a coefficient.
1. H2 + O2 → H2O
2. H2 + N2 → NH3
3. Al2O3 → Al + O2
4. KClO3 → KCl + O2
5. S8 + O2 → SO2
6. C2H6 + O2 → CO2 + H2O
7. Al2(SO4)3 + Ca(OH)2 → Al(OH)3 + CaSO4
8. P4 + O2 → P2O5
9. Ag + S8 → Ag2S
10. Al + Br2 → AlBr3
11. Cr + O2 → Cr2O3
12. NaClO3 → NaCl + O2
13. AlBr3 + Cl2 → AlCl3 + Br2
14. Na + H2O → NaOH + H2
15. AlI3 + HgCl2 → AlCl3 + HgI2
16. Ca(OH)2 + H3PO4 → Ca3(PO4)2 + H2O
17. AgNO3 + K3PO4 → Ag3PO4 + KNO3
18. C3H8 + O2 → CO2 + H2O
19. C2H2 + O2 → CO2 + H2O
20. C6H6 + O2 → CO2 + H2O
WRITE THE COMPLETE PRODUCT AND BALANCE THE EQUATION
When heated, aluminium reacts with solid copper oxide to produce copper metal and aluminium oxide:
Al + CuO → Al2O3 + ___
Potassium oxide is not a stable compound. In the presence of water (or even water vapour in the air), it readily converts into potassium hydroxide:
K2O + H2O → _____
When calcium chloride solution is mixed with silver nitrate solution, a thick white precipitate (solid) of silver chloride appears. This is because silver chloride is insoluble: when silver ions and chloride ions find themselves together in solution, they immediately react together to form the solid. This leaves the calcium ions and nitrate ions in solution, effectively forming calcium nitrate solution.
CaCl2 + AgNO3 → AgCl + ____
Magnesium will react with phosphorus to form magnesium phosphide, a chemical widely used in industry.
Mg + P4 → ____