Download 1 Chemical Reactions: Chemistry Word Equations • Write the names

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Chemical Reactions: Chemistry
Word Equations
• Write the names of the ________________________ to the _________ of the arrow
• Reactants and products are separated by ________ signs
• Write the names of the ________________________ to the _________ of the arrow
– Ex:
Iron(III) + oxygen ________________________
– Reads: Iron reacts with oxygen to produce iron 3 oxide
Chemical Reactions
• Reactants  Products
• Reactants are on the _________ of the arrow
• Products are on the _________ of the arrow
• _________________= yields, gives, reacts to produce
Chemical Equations
• Are _____________________ of a chemical reaction
• Fe + O2  Fe2O3
{RUST}
• Skeleton Equation: is a chemical equation that does not indicate the
_______________________ of the reactants and products.
• Fe + O2  Fe2O3
– Not balanced
– 1 Fe, 2 O  2 Fe, 3 O
• Symbols used in chemical equations:
– + : ______________________________________
– : “yeilds” ; _______________________________
– (s): ______________
– (l): ______________
– (g): ______________
– (aq): aqueous; ____________________________
– ∆: ____________________________
• 4Fe + 3O2  2Fe2O3
• Coefficients: small ____________________________ that are placed in front of formulas
in equation in order to balance it
• Balanced equation: each side of the equation has the _________ number of atoms of
each element (mass conserved)
Law of Conservation of Mass
• Matter can neither be ______________________ nor ______________________
Balancing Equations
• H2
+
O2

H2O
– Unbalanced
– H=
H=
– O=
O=
2
•
•
__H2 + __O2

__H2O
2 H2 + 1 O2

2 H2O
– H=
H=
– O=
O=
Balancing Rules
1. Determine the correct ____________________ for all the reactants and products.
2. Write the _______________________ equation. (Reactants on left, products on right,
yield sign in between. If two or more reactants/products are involved, separate their
formulas with plus signs.
3. Determine the number of ________________ of each element in the reactants and
products. (Count polyatomic ion as a single unit if it appears unchanged on both sides of
the equation)
4. Balance the elements one at a time by using ______________________. When no
coefficient is written, it is assumed to be ____. Begin by balancing elements that appear
only once on each side of the equation. Never balance an equation by changing the
subscripts in a chemical formula. Each substance has only one correct formula.
5. Check each atom or polyatomic ion to be sure they are __________ on both sides of the
equation.
6. Make sure all the coefficients are in the ___________________ possible ratios.
Balancing Practice
• ZnO  Zn + O2
•
Be + O2  Be2O
•
S + O2  SO3
•
Na + Cl2  NaCl
•
C3 H8 + O2  CO2 + H2O
•
S + O2  S4 + O10
Balancing Practice
• Na + H2 O  NaOH + H2
•
K2O + H2O  KOH
•
Al + HCl  AlCl3 + H2
•
C7H6O2 + O2  CO2 + H2O
•
Al2 (SO4) 3 + Ca(OH) 2  Al(OH) 3 + CaSO4
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Synthesis
• A reaction in which two or more reactants yield a ______________________ product.
– AKA: _____________________________________
• General Equation
___ + ___  ________
• EX: 2 Li + Se ---> Li2Se
•
• Complete and balance this equation for a synthesis reaction:
• Be + O2 
• _____________________  ______________________
• Write and balance the equation for the formation of magnesium nitride (Mg3N2) from its
elements.
•
 2Mg3N2
• _________________________ _________________________
Decomposition
 One Reactant Breaking Down into __________ or _____________ products
 General Equation
o ______ ---> ___ + ___
 Example:
o 2 HgO  2 Hg + O2
 Complete and balance this decomposition reaction:
o HI 
o _________________________ _________________________
 Write the formula for the binary compound that decomposes to the products H2 and Br2.
o _________________________ _________________________
Combustion
 One or more reactants combine with ________________ releasing _________ or
__________
 Must include the reactant _________________, O2
 General Equation 1 & 2:
o 1)____ + O2  _______
o Ex: 2Mg(s) + O2(g)  2MgO(s)
o 2)Hydrocarbon + O2  ____________ + _______________________ + Energy
o ________ + O2  H2O + CO2
Single Displacement
• AKA: ______________________
• One element ______________________ a similar element in a compound
• General Eq: ___ + ______  ______ + ___
•
2 Na + 2 HOH  2 NaOH + H2
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Activity Series of Metals
•
Lists metals in order of ______________________ reactivity
•
Metals from Li to Na will replace _________ from acids and water
•
Metals from Mg to Pb will replace _________ from acids only
•
PAGE: 333
Single Replacement Reactions
•
The reactions take place in aqueous solution; Complete the reactions:
– Zn(s) + H2SO4(aq) 
– ______________________  ______________________
– Cl2(aq) + NaBr(aq) 
– ______________________  ______________________
Double Displacement
•
Reaction that has the interchanging of two _______ from two different
___________________.
•
general form:
______ + ______  ______ + ______
•
Example:
Pb(NO3)2 + 2 KI ----> PbI2
+ 2 KNO3
•
Equation consists of two ____________________ that have both a cation and anion.
•
During a reaction the cations (or anions) _________________ places.
•
The products usually consist of a
– ________________________________
– ________________________________
– ________________________________ (ex: water)
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•
Write a balanced chemical equation for:
– CaBr2(aq) + AgNO3(aq) (a precipitate of silver bromide is formed)
– ______________________  ______________________
– FeS(s) + HCl(aq)  (Hydrogen sulfide gas (H2S is formed)
– ______________________  ______________________
Reaction Checklist
•
1) Is O2 a reactant?
– ________________________________________
•
2) One product?
– ________________________________________
•
3) One reactant?
– ________________________________________
•
4) Is an element being replaced?
– ________________________________________
•
5) 2 switches?
– ________________________________________
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Balancing Equations and Determining Reactions
O2 → P4O10
1. ____ P +
2. ____ Mg +
→
O2
3. ____ HgO →
Hg
9. ____ HgO
+ Cl2 →
10. ____ C +
H2
MgO
+
→
Al
+
NaBr →
6. ____ H2 + N2 →
7. ____ Na
+
Br2
KCl +
NaCl +
F2 →
+
O2
SF6
Br2
13. ____ HgO
+ Cl2 →
14. ____ C +
H2
HgCl + O2
NH3
→
H2S →
→
CH4
NaBr
15. ____ BaCl2 +
8. ____ CuCl2 +
CH4
O2
12. ____ S8
5. ____ Cl2 +
→
O2
11. ____ KClO3 →
4. ____ Al2O3
HgCl + O2
CuS +
HCl
BaSO4
Na2 SO4 →
NaCl +