Quiz #5 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 Hydrogen?

3. In the formula Ca3 (PO4)2 What elements are present?

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

5. Balance the following:__N2 + __H2 __NH3

6. What does C2H6 (g) symbolize if this is the symbol for ethane?

7. Predict the following reaction:__Al + __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. H2

3. Calcium, phosphorous, oxygen

4. 3 Ca, 2 P, 8 O

5. N2 + 3 H2 2 NH3

6. Gaseous ethane7. 2 Al+ 3 Cl2 2 AlCl3

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

hydroxides. ex:• K2O + H2O ________• Many oxides of nonmetals react with water to

form oxyacids. ex:• P2O5 + 3 H2O _________

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

• CaO + SO3 ________• Active metals react with halogens to form salts.• __Cs + Br2-

2KOH

2 H3PO4

CaSO4

2 CsBr2

Practice Decomposition reactions

• __CsOH

• __Al(OH)3

• __Na2CO3

• __CsClO3

• __Mg(ClO3)2

• __Ba(OH)2

• 2 CsOH Cs2O + H2O

• 2 Al(OH)3 Al2O3 + 3H2O

• Na2CO3 Na2O + CO2

• 2 CsClO3 -> 2CsCl + 3 O2

• Mg(ClO3)2 MgCl2 + 3 O2

• Ba(OH)2 BaO + 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