Gas Tests

1
Gas Tests
2

• Gas Test Positive
• O2

3

• Gas Test Positive
• O2 glowing splint

4

• Gas Test Positive
• O2 glowing splint reignites
• H2

5

• Gas Test Positive
• O2 glowing splint reignites
• H2 burning splint

6

• Gas Test Positive
• O2 glowing splint reignites
• H2 burning splint pops
• CO2

7

• Gas Test Positive
• O2 glowing splint reignites
• H2 burning splint pops
• CO2 limewater

8

• Gas Test Positive
• O2 glowing splint reignites
• H2 burning splint pops
• CO2 limewater cloudy

9
Synthesis and Decomposition Reactions
10

• Phase symbols (s, l, g, aq) are used to indicate
  phases of
• reactants and products.
• Polyatomic Elements P4 (s) and S8 (s)
• Diatomic Elements H2 (g), N2 (g) O2 (g), F2 (g),
  Cl2 (g), Br2 (l), I2(s)

11
Synthesis means to make or combine. Elements
combine to form compounds.
12
Synthesis means to make or combine. Elements
combine to form compounds. A B ? AB
13
Synthesis means to make or combine. Elements
combine to form compounds. A B ? AB
O2 S8
14
Synthesis means to make or combine. Elements
combine to form compounds. A B ? AB
O2 (g) S8 (s)
15
Synthesis means to make or combine. Elements
combine to form compounds. A B ? AB
O2 (g) S8 (s) ? SO2 (g)
16
Synthesis means to make or combine. Elements
combine to form compounds. A B ? AB 8
O2 (g) S8 (s) ? 8 SO2 (g)
17
Synthesis means to make or combine. Elements
combine to form compounds. A B ? AB 8
O2 (g) S8 (s) ? 8 SO2 (g)
18
Synthesis means to make or combine. Elements
combine to form compounds. A B ? AB 8
O2 (g) S8 (s) ? 8 SO2 (g)
Li N2
19
Synthesis means to make or combine. Elements
combine to form compounds. A B ? AB 8
O2 (g) S8 (s) ? 8 SO2 (g)
Li(s) N2 (g)
20
Synthesis means to make or combine. Elements
combine to form compounds. A B ? AB 8
O2 (g) S8 (s) ? 8 SO2 (g)
Li(s) N2 (g) ? Li3N(s)
21
Synthesis means to make or combine. Elements
combine to form compounds. A B ? AB 8
O2 (g) S8 (s) ? 8 SO2 (g)
6 Li(s) N2 (g) ? 2
Li3N(s)
22
Synthesis means to make or combine. Elements
combine to form compounds. A B ? AB 8
O2 (g) S8 (s) ? 8 SO2 (g) 6
Li(s) N2 (g) ? 2 Li3N(s) Ionic
compounds are solid
23
Decomposition means to break down. Compounds
break down into elements, therefore requiring
energy (heating or adding electricity).
24
Decomposition means to break down. Compounds
break down into elements, therefore requiring
energy (heating or adding electricity). AB
? A B HgO
25
Decomposition means to break down. Compounds
break down into elements, therefore requiring
energy (heating or adding electricity). AB
? A B HgO (s)
26
Decomposition means to break down. Compounds
break down into elements, therefore requiring
energy (heating or adding electricity). AB
? A B HgO (s) ?
means heat
27
Decomposition means to break down. Compounds
break down into elements, therefore requiring
energy (heating or adding electricity). AB
? A B HgO (s) ? Hg (l)
O2 (g)
28
Decomposition means to break down. Compounds
break down into elements, therefore requiring
energy (heating or adding electricity). AB
? A B 2 HgO (s) ? 2 Hg (l)
O2 (g)
29
Decomposition means to break down. Compounds
break down into elements, therefore requiring
energy (heating or adding electricity). AB
? A B 2 HgO (s) ? 2 Hg (l)
O2 (g) H2O (l) ?
30
Decomposition means to break down. Compounds
break down into elements, therefore requiring
energy (heating or adding electricity). AB
? A B 2 HgO (s) ? 2 Hg (l)
O2 (g) H2O (l) ?
electrolysis
31
Decomposition means to break down. Compounds
break down into elements, therefore requiring
energy (heating or adding electricity). AB
? A B 2 HgO (s) ? 2 Hg (l)
O2 (g) H2O (l) ? H2 (g)
O2 (g)
electrolysis
32
Decomposition means to break down. Compounds
break down into elements, therefore requiring
energy (heating or adding electricity). AB
? A B 2 HgO (s) ? 2 Hg (l)
O2 (g) 2 H2O (l) ? 2 H2 (g)
O2 (g)
electrolysis
33

• Examples
• Molten table salt is electrolyzed to produce
  molten sodium and another gas.

34

• Examples
• Molten table salt is electrolyzed to produce
  molten sodium and another gas.
• 2 NaCl (l) ? 2 Na (l) Cl2 (g)
• Nitrogen from the air reacts with oxygen to
  produce gaseous nitrogen dioxide.

35

• Examples
• Molten table salt is electrolyzed to produce
  molten sodium and another gas.
• 2 NaCl (l) ? 2 Na (l) Cl2 (g)
• Nitrogen from the air reacts with oxygen to
  produce gaseous nitrogen dioxide.
• N2 (g) 2 O2 (g) ? 2 NO2 (g)

36
Classify is synthesis or decomposition, then
predict the products and balance A sample of
Copper II oxide is heated.
37
Classify is synthesis or decomposition, then
predict the products and balance A sample of
Copper II oxide is heated. Decomposition
38
Classify is synthesis or decomposition, then
predict the products and balance A sample of
Copper II oxide is heated. Decomposition 2
CuO(s) ? 2 Cu (s) O2 (g) A
silver spoon tarnishes when exposed to sulfur.
39
Classify is synthesis or decomposition, then
predict the products and balance A sample of
Copper II oxide is heated. Decomposition 2
CuO(s) ? 2 Cu (s) O2 (g) A
silver spoon tarnishes when exposed to sulfur.
Synthesis
40
Classify is synthesis or decomposition, then
predict the products and balance A sample of
Copper II oxide is heated. Decomposition 2
CuO(s) ? 2 Cu (s) O2 (g) A
silver spoon tarnishes when exposed to sulfur.
Synthesis 16 Ag (s) S8 (s) ? 8
Ag2S (s) Molten lye (sodium hydroxide) is
decomposed industrially into its elements.
41
Classify is synthesis or decomposition, then
predict the products and balance A sample of
Copper II oxide is heated. Decomposition 2
CuO(s) ? 2 Cu (s) O2 (g) A
silver spoon tarnishes when exposed to sulfur.
Synthesis 16 Ag (s) S8 (s) ? 8
Ag2S (s) Molten lye (sodium hydroxide) is
decomposed industrially into its elements.
Decomposition
42
Classify is synthesis or decomposition, then
predict the products and balance A sample of
Copper II oxide is heated. Decomposition 2
CuO(s) ? 2 Cu (s) O2 (g) A
silver spoon tarnishes when exposed to sulfur.
Synthesis 16 Ag (s) S8 (s) ? 8
Ag2S (s) Molten lye (sodium hydroxide) is
decomposed industrially into its elements.
Decomposition 2 NaOH(l) ? 2 Na (s)
O2 (g) H2 (g)
43
Classify is synthesis or decomposition, then
predict the products and balance A sample of
Copper II oxide is heated. Decomposition 2
CuO(s) ? 2 Cu (s) O2 (g) A
silver spoon tarnishes when exposed to sulfur.
Synthesis 16 Ag (s) S8 (s) ? 8
Ag2S (s) Molten lye (sodium hydroxide) is
decomposed industrially into its elements.
Decomposition 2 NaOH(l) ? 2 Na (s)
O2 (g) H2 (g) Homework Worksheet 1 (Unit
4 p. 109)