C4 Flashcards
(158 cards)
1
Q
What are Group 1 elements also known as?
A
Group 1 elements are called the alkali metals because they react with water to form alkaline solutions.
2
Q
What is the state of alkali metals at room temperature?
A
The alkali metals are in the solid state at room temperature.
3
Q
How does the hardness of alkali metals change down the group?
A
Lithium is the hardest, and each alkali metal is softer as you go down the group.
4
Q
What trend is observed in the density of Group 1 elements?
A
Density generally increases down Group 1.
5
Q
What trend is observed in the melting point of Group 1 elements?
A
The melting point decreases down Group 1.
6
Q
How do alkali metals react with water?
A
The alkali metals react with water to produce the metal hydroxide and hydrogen.
7
Q
What is the balanced equation for sodium reacting with water?
A
2Na(s) + 2H₂O(l) → 2NaOH(aq) + H₂(g)
8
Q
What happens to lithium when it reacts with water?
A
Lithium fizzes steadily and slowly disappears.
9
Q
What happens to sodium when it reacts with water?
A
Sodium melts to form a silvery ball, fizzes vigorously, and quickly disappears.
10
Q
What happens to potassium when it reacts with water?
A
Potassium immediately ignites, burns with a lilac flame, and very quickly disappears.
11
Q
Why do Group 1 elements have similar chemical properties?
A
All their atoms have one electron in their outer shell.
12
Q
What is the general ionic equation for Group 1 metals?
A
M → M⁺ + e
13
Q
Why is potassium more reactive than lithium?
A
Potassium’s atoms lose their outer electron more easily than lithium’s atoms do.
14
Q
How are Group 1 elements stored to prevent reactions?
A
The Group 1 elements are stored in oil to prevent them from reacting with oxygen in the air and with water.
15
Q
What does the word ‘halogen’ mean?
A
The word ‘halogen’ comes from the Greek word ‘halos’ meaning ‘salt’, and ‘gen’ means ‘maker’.
16
Q
What causes stinging eyes after swimming?
A
Stinging eyes are caused by chloroamines, compounds formed when chlorine reacts with sweat and other body substances.
17
Q
What are the physical states and colors of the Group 7 elements at room temperature?
A
Fluorine (F) is a pale yellow gas, chlorine (Cl) is a green gas, bromine (Br) is an orange-brown liquid, and iodine (I) is a shiny grey-black solid that sublimes to a purple vapor.
18
Q
What trends occur when going down Group 7 (IUPAC Group 17)?
A
Density, melting points, and boiling points increase.
19
Q
What is the reaction of Group 7 elements with metals?
A
Group 7 elements react with metals to produce salts, reacting vigorously with Group 1 metals.
20
Q
Provide an example of a reaction between a Group 1 metal and a halogen.
A
Sodium reacts with chlorine to produce sodium chloride: 2Na(l) + Cl2(g) → 2NaCl(s).
21
Q
How does reactivity change down Group 7?
A
The reactivity of halogens decreases down the group.
22
Q
What is the general ionic equation for halogens gaining an electron?
A
X + 2e → 2X-.
23
Q
Why is chlorine more reactive than iodine?
A
Chlorine is more reactive because its atoms gain an outer electron more easily than iodine atoms.
24
Q
What is the physical state and color of astatine?
A
Astatine is an extremely rare, radioactive element.
25
What are the typical properties of Group 7 (IUPAC Group 17) elements?
They are brittle in solid state, poor conductors of electricity, exist as diatomic molecules, and have weak intermolecular forces.
26
What is a halogen displacement reaction?
Halogens can react with halides in solution, where a halide is a compound containing a Group 7 element and one other element, usually hydrogen or a metal.
27
What happens when chlorine reacts with sodium bromide solution?
Chlorine displaces bromine, forming sodium chloride and bromine, resulting in an orange-brown color as bromine is produced.
28
Which halogens can displace others in displacement reactions?
Chlorine displaces bromine from bromides and iodine from iodides. Bromine displaces iodine from iodides but cannot displace chlorine from chlorides. Iodine cannot displace chlorine from chlorides or bromine from bromides.
29
Why is it safer to use aqueous solutions of halogens in school?
It is safer to use aqueous solutions rather than the pure elements due to the reactivity and hazards of the pure halogens.
30
What is a halide?
A halide is a compound of a Group 7 element and one other element, such as hydrogen chloride and sodium chloride.
31
What is a halide ion?
A halide ion is a negative ion formed by a Group 7 element, for example, chloride ions from chlorine.
32
How can halogen displacement reactions confirm the order of reactivity for chlorine, bromine, and iodine?
By conducting experiments with pairs of halogen solutions and observing the reactions.
33
What is the ionic equation for chlorine displacing bromine from bromide ions?
Cl2 + 2Br- → 2Cl- + Br2
## Footnote
This represents a redox reaction.
34
What should be noted when conducting halogen displacement reactions in a practical setting?
Wearing eye protection and ensuring that asthmatics do not breathe in chemical fumes.
35
What is the word equation for the displacement reaction between chlorine and lithium iodide?
Chlorine + Lithium Iodide → Iodine + Lithium Chloride
36
Can iodine displace astatine from sodium astatide?
No, iodine cannot displace astatine due to its lower reactivity.
37
Why can fluorine displace chlorine from sodium chloride solution?
Fluorine is more reactive than chlorine.
38
What is the balanced equation for the reaction of fluorine with sodium chloride?
F2(g) + 2NaCl(aq) → 2NaF(aq) + Cl2(g)
39
What is the ionic equation for the reaction of fluorine with sodium chloride?
F2 + 2Cl- → 2F- + Cl2
## Footnote
This represents a redox reaction.
40
What are the properties of Group 0 (IUPAC Group 18) elements?
Group 0 elements are non-metals, placed in a vertical column on the far right of the Periodic Table, and are in the gas state at room temperature.
41
Why are Group 0 (IUPAC Group 18) elements unreactive?
They have complete outer electron shells, meaning they do not tend to lose, gain, or share electrons.
42
What is the electronic structure of helium?
Helium has 2 electrons in its outer shell.
43
What is the electronic structure of neon?
Neon has 8 electrons in its outer shell.
44
What is the electronic structure of argon?
Argon has 8 electrons in its outer shell.
45
What trends do noble gases show in terms of boiling points?
Boiling points increase as you go down Group 0 (IUPAC Group 18) due to stronger attractive forces between atoms.
46
What is the trend in density for noble gases?
Density increases as you go down Group 0 (IUPAC Group 18) because atoms are farther apart in the gas state.
47
Why were Group 0 (IUPAC Group 18) elements previously called inert gases?
They were thought to not react at all until the first noble gas compound was made in 1962.
48
What is the significance of Neil Bartlett's work in 1962?
He made the first noble gas compound, XePtF, demonstrating that noble gases can form compounds.
49
Why do helium and neon balloons rise in air?
They are less dense than air, which has a density of 1.20 g/dm³.
50
What is the predicted position of ununoctium (Uuo) in the Periodic Table?
Uuo is placed below radon and may be a metal rather than a non-metal.
51
What are the general properties of transition metals?
Transition metals are shiny when freshly cut, good conductors of electricity, strong, and malleable.
52
Where are transition metals located in the Periodic Table?
Transition metals are placed between Groups 2 and 3, occupying IUPAC Groups 3 to 12.
53
How do transition metals compare to alkali metals?
Transition metals are stronger and harder, have higher densities, and have higher melting points (except for mercury).
54
What is an example of a transition metal used in everyday objects?
Copper is a good conductor of electricity and can be made into strong, flexible electrical wires.
55
What are the chemical properties of transition metals?
Transition metals are less reactive than alkali metals and react slowly, if at all.
56
What do transition metals produce when they react?
Transition metals produce colored ionic compounds.
57
What is the significance of the names of transition metals?
Many transition metal names reflect the colors of their ions, such as iridium from 'iris' and rhodium from 'rhodon'.
58
How do transition metals form ions?
Many transition metals can form more than one type of ion, such as iron (II) oxide, FeO, and iron (III) oxide, Fe2O3.
59
What is a catalyst?
A catalyst is a substance that increases the rates of chemical reactions without being used up.
60
What transition metals are used in catalytic converters?
Platinum, rhodium, and palladium are used in catalytic converters.
61
What is the color of sodium sulfate solution?
Sodium sulfate solution is colorless.
62
What is the symbol for the vanadium ion in V2O5?
The symbol for the vanadium ion in V2O5 is V5+.
63
Why are platinum and iridium suitable for making electrodes for electrolysis?
Platinum and iridium are suitable due to their properties, such as resistance to corrosion and good conductivity.
64
What should you be able to explain after studying C4.1.6?
The reactivity of different metals.
65
What can you use to order metals by reactivity?
Experimental data.
66
How can you predict the reactions of elements?
From their position in the Periodic Table.
67
What is the most reactive metal in the reactivity series?
Potassium.
68
What is the least reactive metal in the reactivity series?
Platinum.
69
What happens when a more reactive metal displaces a less reactive metal?
A metal displacement reaction occurs.
70
What do metals form in reactions with water?
Metal hydroxides and hydrogen.
71
What do metals form in reactions with acids?
Salts and hydrogen.
72
What does a higher rate of reaction indicate?
Greater reactivity of the metal.
73
What should you wear during metal reactions?
Eye protection.
74
What is an example of a metal displacement reaction?
Cu(s) + 2AgNO3(aq) → Cu(NO3)2(aq) + 2Ag(s)
## Footnote
This shows copper displacing silver from silver nitrate solution.
75
Why can iron displace copper from copper(II) nitrate solution?
Iron is more reactive than copper.
76
What is the trend in reactivity for metals in Groups 1 and 2?
They become more reactive down the group.
77
What happens to non-metals in Group 7 as you go down the group?
They become less reactive.
78
What should you not do when testing metal reactivity with water or acid?
Do not boil the water or dilute hydrochloric acid.
79
What is one method to determine the reactivity of an unknown metal?
Conduct displacement reactions with known solutions.
80
What observation would indicate a reaction in a displacement experiment?
Bubbling or color change.
81
How do you detect carbon dioxide?
You test for carbon dioxide using limewater, which turns cloudy white when carbon dioxide is bubbled through it.
## Footnote
The reaction forms water and a white precipitate of calcium carbonate.
82
What is the balanced equation for the reaction between calcium hydroxide and carbon dioxide?
Ca(OH)₂ (aq) + CO₂ (g) → CaCO₃ (s) + H₂O (l)
83
How do you detect chlorine?
Chlorine dissolves in water to form an acidic solution and bleaches dyes. A test involves dampening blue litmus paper, which turns red then white in the presence of chlorine.
## Footnote
The litmus paper must be damp for the chlorine test to work.
84
What are the steps to safely smell substances in the laboratory?
1. With the container well away from your nose, breathe in enough air to almost fill your lungs. 2. Hold the container a few centimeters away from your nose and waft any smell towards you.
85
How do you test for hydrogen?
Place a lighted splint near the mouth of the container of gas. If hydrogen is present, it should ignite with a squeaky pop.
86
How do you test for oxygen?
Place a glowing splint near the mouth of the container of gas. If oxygen is present, the splint should relight.
87
What happens to damp starch-iodide paper in the presence of chlorine?
Damp starch-iodide paper turns blue-black in the presence of chlorine due to chlorine displacing iodine from iodide ions.
## Footnote
The starch in the paper then turns blue-black.
88
What is the balanced equation for the reaction between water and carbon dioxide to form carbonic acid?
CO₂ (g) + H₂O (l) → H₂CO₃ (aq)
89
Why does the calcium carbonate precipitate re-dissolve when excess carbon dioxide is bubbled through limewater?
The excess carbon dioxide reacts with the water to form carbonic acid, which can dissolve the calcium carbonate precipitate.
90
What should you be able to do after studying C4.2.2?
Describe how to carry out and interpret flame tests and hydroxide precipitate tests to identify aqueous metal ions.
91
Who invented the Bunsen burner?
The Bunsen burner was developed by Peter Desaga, a technician of Robert Bunsen, who needed a clean, hot flame for experiments.
92
What happens to metal ions during a flame test?
When heated, energy is transferred to their electrons, causing them to move to higher electron shells and emit light as they return to normal shells.
93
What are the flame test colors for lithium, sodium, potassium, calcium, and copper?
Lithium - crimson, Sodium - yellow, Potassium - lilac, Calcium - orange-red, Copper - green-blue.
94
How do you carry out a flame test?
1. Dip a clean nichrome wire loop into the test powder or solution. 2. Hold it in the edge of a roaring blue flame. 3. Record the flame color.
95
What is the advantage of using disposable damp wooden splints for flame tests?
They can reduce the risk of contamination between tests compared to metal loops.
96
What are hydroxide precipitate tests?
Tests that identify metal ions based on the color of precipitates formed when sodium hydroxide solution is added.
97
What is the reaction for forming copper(II) hydroxide?
CuSO₄(aq) + 2NaOH(aq) → Cu(OH)₂(s) + Na₂SO₄(aq)
98
What colors do different metal hydroxides produce?
Iron(II) - orange-brown, Iron(III) - brown, Copper(II) - blue, Calcium - white, Zinc - white.
99
How can you distinguish between iron(II) chloride and iron(III) chloride?
By observing the color of the precipitate formed when sodium hydroxide is added.
100
What happens to zinc hydroxide when excess sodium hydroxide is added?
Zinc hydroxide dissolves to form a colorless solution, while calcium hydroxide does not.
101
What tests would you use to distinguish between calcium chloride and zinc chloride?
Add sodium hydroxide; calcium chloride will not form a precipitate, while zinc chloride will form a white precipitate.
102
What are the learning outcomes for detecting anions?
After studying this lesson you should be able to describe tests to detect sulfates, carbonates, and halides, and identify compounds from test results.
103
How do you detect sulfate ions?
Barium ions react with sulfate ions to produce white, insoluble barium sulfate: Ba²⁺(aq) + SO₄²⁻(aq) → BaSO₄(s). To test for sulfate ions, add a few drops of dilute hydrochloric acid followed by barium chloride solution. A white precipitate indicates the presence of sulfate ions.
104
What is the balanced equation for the reaction between barium chloride solution and sodium sulfate solution?
BaCl₂(aq) + Na₂SO₄(aq) → BaSO₄(s) + 2NaCl(aq)
105
How do you detect carbonate ions?
Hydrogen ions from dilute acids react with carbonate ions to produce carbon dioxide and water: 2H⁺(aq) + CO₃²⁻(aq) → CO₂(g) + H₂O(l). To test for carbonate ions, add a few drops of dilute hydrochloric acid. Bubbles of gas indicate the presence of carbonate ions.
106
How can you confirm that the gas produced from carbonate ions is carbon dioxide?
You can confirm that the gas is carbon dioxide by bubbling it through limewater.
107
How do you detect halide ions?
Add a few drops of dilute nitric acid followed by a few drops of silver nitrate solution, AgNO₃(aq). A precipitate indicates the presence of chloride, bromide, or iodide ions.
108
What are the colours of silver halide precipitates?
Chloride: white, Bromide: cream, Iodide: yellow.
109
What is a study tip for remembering the colours of silver halide precipitates?
Think of 'milk, cream, butter' - milk is white and butter is yellow.
110
What is a suitable precaution when carrying out tests for sulfate ions?
Soluble barium salts are toxic, so handle them with care.
111
Why is barium sulfate used for medical imaging but barium chloride is not?
Barium sulfate is insoluble and safe for imaging, while barium chloride is soluble and toxic.
112
How would you carry out a test to detect carbonate ions in silver carbonate?
Add dilute hydrochloric acid to silver carbonate. Bubbles of gas will indicate the presence of carbonate ions.
113
Why is dilute nitric acid added first when testing for halide ions using silver nitrate solution?
Dilute nitric acid removes any carbonate or hydroxide ions that could interfere with the test.
114
How would you distinguish between sodium iodide, potassium sulfate, and potassium carbonate?
Perform tests for sulfate, carbonate, and halide ions, observing the results for precipitates and gas production.
115
What are the learning outcomes of C4.2.4 Instrumental methods of analysis?
After studying this lesson, you should be able to describe the advantages of using scientific instruments to analyse substances and interpret results from an instrumental analysis.
116
What is an instrumental method of analysis?
An instrumental method of analysis relies on a machine to carry out an analysis of a substance.
117
What are the advantages of instrumental methods of analysis?
The advantages include sensitivity, accuracy, and speed.
118
Why are instrumental methods of analysis useful for analysing samples from a crime scene?
They provide accurate and quick results, which are essential in forensic investigations.
119
How do you interpret gas chromatograms?
In a gas chromatogram, each peak represents a substance present in the mixture, the areas under each peak show the relative amount of each substance, and the retention time is different for different substances.
120
How can a gas chromatogram be used to determine if a driver is over the legal limit for alcohol?
The chromatogram can show the concentration of alcohol in the driver's urine sample.
121
What does a mass spectrometer measure?
A mass spectrometer measures the masses of atoms and molecules, and is used to analyse the relative amounts of different isotopes and the structure of molecules.
122
What does each peak in a mass spectrum represent?
Each peak represents a fragment of the molecule, with the peak on the far right representing the molecular ion.
123
What is the mass to charge ratio of the molecular ion peak equal to?
It is equal to the relative formula mass of the molecule.
124
What are two advantages of instrumental methods of analysis?
Sensitivity and accuracy.
125
Why combine a gas chromatogram with a mass spectrometer?
Combining these instruments allows for more detailed analysis of substances as they leave the chromatography column.
126
What does an infrared spectrometer detect?
It detects covalent bonds in a molecule.
127
What are the wavenumbers for different bonds in an infrared spectrum?
C-H: 2850-3300, C-C: 750-1100, C=Cl: 1620-1680, C-O: 1000-1300, N-H: 3230-3550, O-H: 3360-3500.
128
What is the purpose of identifying reactions?
To identify compounds from test results.
129
What are the advantages of using scientific instruments?
They provide sensitivity, accuracy, and speed in analyzing substances.
130
What does the reactivity series indicate?
It ranks metals from most reactive (potassium) to least reactive (platinum).
131
How can you test for hydrogen gas?
A lighted splint ignites the gas with a pop.
132
How can you test for oxygen gas?
A glowing splint relights in the presence of oxygen.
133
What happens when chlorine gas is tested?
Damp blue litmus paper turns red then white.
134
How can you test for carbon dioxide?
It turns limewater cloudy.
135
What is the method for conducting flame tests?
Use a nichrome wire loop and Bunsen burner to observe flame colors of different metal cations.
136
What flame color does lithium produce?
Red.
137
What flame color does sodium produce?
Yellow.
138
What flame color does potassium produce?
Lilac.
139
What flame color does calcium produce?
Orange-red.
140
What flame color does copper produce?
Green-blue.
141
What is the method for hydroxide precipitate tests?
Use sodium hydroxide solution to identify different colored precipitates from metals.
142
What precipitate color indicates iron(II)?
Green.
143
What precipitate color indicates copper?
Blue.
144
What precipitate color indicates calcium?
White.
145
What is the method for detecting halide ions?
Add dilute nitric acid and silver nitrate solution, then observe the color of the precipitate.
146
What precipitate color indicates chloride ions?
White.
147
What precipitate color indicates bromide ions?
Cream.
148
What precipitate color indicates iodide ions?
Yellow.
149
What is the method for the sulfate ion test?
Add dilute hydrochloric acid and barium chloride solution, then look for a white precipitate.
150
What is the method for the carbonate ion test?
Add dilute nitric acid, look for bubbles, and confirm gas is carbon dioxide using limewater.
151
What are the characteristics of Group 1 - Alkali metals?
They are solid at room temperature, float on water, and are reactive.
152
What happens to reactivity in Group 1 as you go down the group?
Reactivity increases as atoms lose electrons.
153
What are the characteristics of Group 7 - Halogens?
They are reactive non-metals with increasing melting and boiling points down the group.
154
What is halogen displacement?
A more reactive halogen displaces a less reactive halogen from its halide ions in solution.
155
What are the characteristics of Group 0 - Noble gases?
They are gases at room temperature and unreactive non-metals.
156
What are the characteristics of transition metals?
They form colored ions with different charges and are used as catalysts.
157
How do transition metals compare to Group 1 metals?
They have higher melting points and are less reactive.
158
What are the advantages of instrumental methods of analysis?
They offer sensitivity, accuracy, and speed in analyses.
