Quiz #4 Chemical Rxns and Safety

1. Why is it important to avoid eating in a chemistry lab?

2. What is the correct way to write the formula for Chlorine?

3. In the formula (NH4)2SO4 What elements are present?

4. How many of each element is present in the formula of ammonium sulfate (in question 3)?

5. Balance the following: __H2 + __N2 __NH3

6. What does C3H8 (l) symbolize if this is the symbol for propane?

7. Predict the following reaction:__K + __Cl2 ______

1. Poisonous chemicals could be left on the desk from previous experiments, eating in lab makes it likely that you will poison yourself.

2. Cl2

3. N, S, H, and O

4. 2 N, 1 S, (2 x 4 =) 8 H, 4 O

5. 3 H2 + N2 2 NH3

6. Liquid propane7. 2 K + Cl2 2 KCl

Practice Synthesis Rxns• Active metal oxides react with water to form

hydroxides. ex:• Na2O + H2O ________• Many oxides of nonmetals react with water to

form oxyacids. ex:• P2O5 + 3 H2O _2________

• Some metal oxides react with nonmetal oxides to form salts.

• K2O + SO3 ________• Active metals react with halogens to form salts.• __Na + Br2-

2NaOH

H3PO4

K2SO4

2 NaBr2

Practice Decomposition reactions

• __NaOH

• __Cr(OH)3

• __MgCO3

• __KClO3

• __Ca(ClO3)2

• __Ca(OH)2

• 2 NaOH Na2O + H2O

• 2 Cr(OH)3 Cr2O3 + 3H2O

• MgCO3 MgO + 3 CO2

• 2 KClO3 -> 2KCl + 3 O2

• Ca(ClO3)2 CaCl2 + 3 O2

• Ca(OH)2 CaO + H2O

Single DisplacementA+ BX AX + Bor:Y + BX BY + X• Replacement of a metal in a compound by another

metal.

2 Al (s) + 3Pb(NO3)2 3Pb +2 Al(NO3)3

Al

Al

Pb2+

N

O

OO

N

O

O

O

NO

O

O

NO

O

O

N

O

O

O

NO

O O

Pb2+

Pb2+

Single DisplacementA+ BX AX + Bor:Y + BX BY + X• Replacement of a metal in a

compound by another metal.2 Al (s) + 3Pb(NO3)2 3Pb +2 Al(NO3)3

Al3+Al3+

Pb

N O

O

OPb

N O

O

O

Pb

NO

O O

NO

O

O

NO

OO

NO

O O

Single DisplacementA+ BX AX + Bor:Y + BX BY + X• Replacement of a hydrogen in a

compound by a metal.2 Na (s) + 2 H2O (l) 2 NaOH (aq) + H2 (g)

Na

NaO

H

H

O

H

H

Single DisplacementA+ BX AX + Bor:Y + BX BY + X• Replacement of a hydrogen in a

compound by a metal.Mg (s) + 2 HCl (aq) MgCl2 (aq) + H2 (g)

Mg

Cl

H

Cl

H

Single DisplacementA+ BX AX + Bor:Y + BX BY + X• Replacement of halogens

Cl2 (g) + 2 KBr (aq) 2 KCl (aq) + Br2 (g)

ClK

Br

Br

K

Cl

http://ncsdweb.ncsd.k12.wy.us/roden/Chemistry/Forms%20PDF/Activity%20Series%20Chart.pdf

Practice: Single Replacement

• Mg + 2 HCl • 2 Fe + 6 HCl • Zn + CuCl2

• Cu + ZnCl2

• Ni + PbCl2

• Sn + PbCl2 • Fe + 3 AgNO3

H2 + MgCl2

3 H2 + 2 FeCl3Cu + ZnCl2

No reactionPb + NiCl2

SnCl2 + Pb

Fe(NO3)3 + 3Ag

• Lithium Fluorine• Potassium Chlorine• Barium Bromine• Strontium Iodine• Calcium• Sodium• Magnesium• Aluminum• Manganese• Zinc• Iron• Cadmium• Cobalt• Nickel• Tin• Lead• Hydrogen• Copper• Silver• Mercury• Gold• Elements CANNOT replace

anything Above them. The reaction does NOT occur in this situation

Less a

ctive

Double Replacement Reactions (double displacement)• Formation of a precipitate.• 2 KI (aq) + Pb(NO3)2 (aq) PbI2 (s) + 2 KNO3 (aq)

K

K

I

Pb2+

N

O

OO

NO

OO

I

Double Replacement Reactions (double displacement)• Formation of a gas.• FeS (s) + 2 HCl(aq) H2S (g) + FeCl2 (aq)

Fe2+S

Cl

H

Cl

H

Double Replacement Reactions (double displacement)• Formation of a water.• NaOH (s) + HCl(aq) H2O (l) + NaCl2 (aq)

Na+

Cl

H

OH

Combustion Reactions

• A substance combines with oxygen, releasing a large amount of energy in the form of light and heat.

2 H2 (g) + O2 (g) 2 H2O

O

H

H

O

H

H

Combustion Reactions• A substance combines with oxygen, releasing a

large amount of energy in the form of light and heat.

C3H8 (g) +5 O2 (g) 4 H2O + 3 CO2

CC C

H

H

HH

H

HH

HO

OO

O

O

O

OO

O

O

Combustion Reactions• A substance combines with oxygen, releasing a

large amount of energy in the form of light and heat.

C3H8 (g) +5 O2 (g) 4 H2O + 3 CO2

C

C

C

HH

H

H

HH

H

H O

OO

O

O

O

OO

O

O