Balancing Chemical Equations
Balance this equation:
___PCl5 → ___PCl3 + ____Cl2
1PCl5 → 1PCl3 + 1Cl2
What are reactants?
The substance(s) presented before a chemical equation.
Atoms can't ever be __ or __ in a chemical reaction.
created, destroyed
Which of these are balanced?
Equation #1: CH4 + O2 -> CO2 + H2O
Equation #2: CO2 + H2 -> CO + H2O
Balanced: Equation #1
CO2 + H2 -> CO + H2O
Balance this equation:
___H2S + 3O2 → ____SO2 + 2H2O
2H2S + 3O2 → 2SO2 + 2H2O
What are products?
The substance(s) produced after a chemical equation.
What is the term used for the elements and compounds before a chemical reaction takes place?
reactant(s)
Which of these is unbalanced?
Equation #1: N2 + H2 -> NH3
Equation #2: H2 + F2 → 2HF
Unbalanced: Equation #2
N2 + H2 -> NH3
Balance this equation:
2Pb(NO3)2 → ____PbO+ 4NO2 + ___O2
2Pb(NO3)2 → 2PbO+ 4NO2 + 1O2
The Law of Conservation of Mass says that the _______ of the reactants must equal the _______ of the products.
mass (and mass)
What is the term used for the elements and compounds after a chemical reaction takes place?
product(s)
Organize these equations into balanced and unbalanced equations:
CuS+ O2 → CuSO4
CO+ 2H2 → CH3OH
Balanced: CO+ 2H2→ CH3OH
Unbalanced: CuS+ O2 → CuSO4
Balance this equation:
___Sb2S3 + ___O2 → ___Sb2O3 + ___SO2
2Sb2S3 + 9O2 → 2Sb2O3 + 6SO2
What is matter?
Anything that has mass and takes up space.
How do you know when a chemical equation is balanced?
When the number of each type of atom is the same on both sides.
Which of these is balanced?
Equation #1: 1N2 + 3H2 -> 2NH3
Equation #2: Al2O3+ 6Cl2→ AlCl3+ 3O2
Equation #3: Sb2S3+ 3Fe → FeS+ Sb
Balanced: Equation #1
1N2 + 3H2 -> 2NH3
Balance this equation(answer is the ratio):
4C2H3N + ___O2 → ___CO2 + 6H2O + ___NO
4C2H3N + 13O2 → 8CO2 + 6H2O + 4NO
What does balanced mean?
A balanced chemical equation shows that no mass was created or destroyed during the reaction.
(same number of each type of atom on each side)
What happens to water as it evaporates?
A. A new substances is formed.
B. It becomes less dense water vapor.
C. Atoms are destroyed.
B. It becomes less dense water vapor.
Which of these are unbalanced?:
Equation #1: 3Zn(OH)2+ H3PO4→ Zn3(PO4)2+ H2O
Equation #2: MnO2+ 4KOH+ O2 → K2MnO4+ H2O
Equation #3: MgO+ H2O → Mg(OH)2
Unbalanced: Equation #1 and #2
3Zn(OH)2+ H3PO4→ Zn3(PO4)2+ H2O
MnO2+ 4KOH+ O2 → K2MnO4+ H2O