Chemistry Flashcards
(324 cards)
1
Q
What sort of extinguisher should be used for a paper fire?
A
Water extinguisher
2
Q
What sort of extinguisher should be used for burning oil spilled on the ground?
A
Foam extinguisher
3
Q
What sort of extinguisher should be used for a chip pan fire?
A
Fire blanket or foam extinguisher
4
Q
What sort of extinguisher should be used for a magnesium fire?
A
Sand or dry powder extinguisher (never water)
5
Q
What sort of extinguisher should be used for an electrical fire?
A
CO₂ (carbon dioxide) extinguisher
6
Q
What are the parts of a Bunsen burner?
A
Base, gas inlet, air hole (collar), barrel, needle valve
7
Q
What are the steps to turn on a bunsen burner so that it is ready to heat a liquid?
A
- Close air hole completely, 2. Turn on gas tap, 3. Light with splint from the side, 4. Open air hole gradually for blue flame
8
Q
What does the corrosive hazard symbol mean?
A
Substance that can destroy or damage living tissue and materials
9
Q
What does the toxic hazard symbol mean?
A
Substance that is poisonous and can cause serious harm or death
10
Q
What does the harmful/irritant hazard symbol mean?
A
Substance that can cause irritation to skin, eyes, or respiratory system
11
Q
What does the flammable hazard symbol mean?
A
Substance that catches fire easily and burns rapidly
12
Q
What are some rules for practical work in the lab?
A
Wear safety goggles, tie back long hair, no running, follow instructions carefully, wash hands after practicals, report accidents immediately
13
Q
How are particles arranged in a solid?
A
Particles closely packed in regular pattern, touching, vibrating in fixed positions
14
Q
How are particles arranged in a liquid?
A
Particles close together but irregular arrangement, can slide past each other
15
Q
How are particles arranged in a gas?
A
Particles far apart, moving randomly in all directions at high speed
16
Q
What state change is lava cooling to form solid rock?
A
Solidification (or freezing)
17
Q
What state change is warm breath on a cold window forming droplets?
A
Condensation
18
Q
What state change is solid carbon dioxide becoming a gas?
A
Sublimation
19
Q
What state change is a puddle drying in the sun?
A
Evaporation
20
Q
What state change is clouds forming from water vapour?
A
Condensation
21
Q
What is diffusion?
A
The spreading of particles from an area of high concentration to an area of low concentration until evenly distributed
22
Q
Why does the white ring form closer to the hydrochloric acid end in the ammonia-HCl tube experiment?
A
White ring is ammonium chloride formed when HCl and NH₃ meet. It’s closer to HCl end because ammonia particles are lighter and move faster than HCl particles
23
Q
Why are air particles not visible under the microscope while smoke particles are?
A
Air particles are too small to be seen, smoke particles are large enough to reflect light
24
Q
How do smoke particles move in Brownian motion?
A
Random, jerky movements in all directions (zigzag motion)
25
What is Brownian motion?
Random movement of visible particles caused by collision with invisible air particles
26
Why do smoke particles move randomly?
Invisible air particles constantly collide with smoke particles from all directions, causing random movement
27
How would smoke particles move if air was not made of particles?
They would not move at all (remain stationary)
28
Why does potassium manganate spread faster in hot water than cold water?
Hot water particles have more kinetic energy causing faster diffusion
29
Is melting exothermic or endothermic?
Endothermic
30
Is condensing exothermic or endothermic?
Exothermic
31
Is evaporation exothermic or endothermic?
Endothermic
32
Is boiling exothermic or endothermic?
Endothermic
33
Is freezing exothermic or endothermic?
Exothermic
34
Is sublimation exothermic or endothermic?
Endothermic
35
Why does temperature stay constant during melting and boiling?
Energy is being used to break bonds between particles rather than increase kinetic energy/temperature
36
What is the symbol for Hydrogen?
H
37
What is the symbol for Helium?
He
38
What is the symbol for Lithium?
Li
39
What is the symbol for Beryllium?
Be
40
What is the symbol for Boron?
B
41
What is the symbol for Carbon?
C
42
What is the symbol for Nitrogen?
N
43
What is the symbol for Oxygen?
O
44
What is the symbol for Fluorine?
F
45
What is the symbol for Neon?
Ne
46
What is the symbol for Sodium?
Na
47
What is the symbol for Magnesium?
Mg
48
What is the symbol for Aluminium?
Al
49
What is the symbol for Silicon?
Si
50
What is the symbol for Phosphorus?
P
51
What is the symbol for Sulphur?
S
52
What is the symbol for Chlorine?
Cl
53
What is the symbol for Argon?
Ar
54
What is the symbol for Potassium?
K
55
What is the symbol for Calcium?
Ca
56
What is the symbol for Iron?
Fe
57
What is the symbol for Nickel?
Ni
58
What is the symbol for Copper?
Cu
59
What is the symbol for Zinc?
Zn
60
What is the symbol for Bromine?
Br
61
What is the symbol for Silver?
Ag
62
What is the symbol for Iodine?
I
63
What is the symbol for Gold?
Au
64
What is the symbol for Lead?
Pb
65
What is the symbol for Platinum?
Pt
66
Where are non-metals found on the Periodic Table?
Right side of the periodic table
67
Where are metals found on the Periodic Table?
Left side and center of the periodic table
68
What are the physical properties of metals?
Shiny (lustrous), conduct electricity and heat, malleable, ductile, high density, high melting points
69
What are the physical properties of non-metals?
Dull (not shiny), don't conduct electricity, brittle when solid, low density, low melting/boiling points
70
Is magnesium oxide acidic or basic?
Basic
71
Is sulphur dioxide acidic or basic?
Acidic
72
Is lithium oxide acidic or basic?
Basic
73
Is phosphorus oxide acidic or basic?
Acidic
74
Are metal oxides generally acidic or basic?
Basic
75
Are non-metal oxides generally acidic or basic?
Acidic
76
How is an alkali different from a base?
An alkali is a base that dissolves in water to form OH⁻ ions
77
What is an element?
A substance made of only one type of atom
78
What is a molecule?
Two or more atoms chemically bonded together
79
What is a compound?
A substance made of two or more different elements chemically bonded
80
What is a mixture?
Two or more substances not chemically bonded, can be separated physically
81
What is the general equation for metals and water?
Metal + Water → Metal Hydroxide + Hydrogen
82
What is the general equation for metal and acid?
Metal + Acid → Salt + Hydrogen
83
What are the three general equations for neutralisation?
1. Acid + Base → Salt + Water, 2. Acid + Metal → Salt + Hydrogen, 3. Acid + Metal Carbonate → Salt + Water + Carbon Dioxide
84
What salt is formed when magnesium reacts with sulphuric acid?
Magnesium sulphate
85
What salt is formed when magnesium reacts with nitric acid?
Magnesium nitrate
86
What salt is formed when magnesium reacts with hydrochloric acid?
Magnesium chloride
87
What gas is produced when a metal reacts with an acid?
Hydrogen
88
What is the test for hydrogen gas?
Lit splint makes a 'pop' sound
89
What gas is produced when a metal carbonate reacts with an acid?
Carbon dioxide
90
What is the test for carbon dioxide gas?
Turns limewater cloudy (milky)
91
What is the chemical formula for a molecule of water?
H₂O
92
What is the chemical formula for two molecules of water?
2H₂O
93
How many atoms are present in two molecules of water?
6 atoms (4 hydrogen + 2 oxygen)
94
How many hydrogen atoms are present in two molecules of water?
4 hydrogen atoms
95
How many oxygen atoms are present in two molecules of water?
2 oxygen atoms
96
Balance: Mg + HCl → H₂ + MgCl₂
Mg + 2HCl → H₂ + MgCl₂
97
Balance: Fe + O₂ → Fe₂O₃
4Fe + 3O₂ → 2Fe₂O₃
98
Balance: C₂H₄ + O₂ → CO₂ + H₂O
C₂H₄ + 3O₂ → 2CO₂ + 2H₂O
99
Balance: SO₂ + H₂O + O₂ → H₂SO₄
2SO₂ + 2H₂O + O₂ → 2H₂SO₄
100
Balance: Al + O₂ → Al₂O₃
4Al + 3O₂ → 2Al₂O₃
101
Write balanced equation: Magnesium oxide + nitric acid → magnesium nitrate + water
MgO + 2HNO₃ → Mg(NO₃)₂ + H₂O
102
Write balanced equation: Potassium iodide + chlorine → potassium chloride + iodine
2KI + Cl₂ → 2KCl + I₂
103
Write balanced equation: Calcium + water → calcium hydroxide + hydrogen
Ca + 2H₂O → Ca(OH)₂ + H₂
104
Write balanced equation: Copper sulphate + aluminium → aluminium sulphate + copper
3CuSO₄ + 2Al → Al₂(SO₄)₃ + 3Cu
105
Write balanced equation: Copper(II) carbonate + hydrochloric acid → copper chloride + water + carbon dioxide
CuCO₃ + 2HCl → CuCl₂ + H₂O + CO₂
106
What does the atomic number in an atom represent?
The number of protons in the nucleus (also equals number of electrons in neutral atom)
107
How do you calculate the mass number of an atom?
Number of protons + Number of neutrons
108
How do you work out the number of neutrons in an atom?
Number of neutrons = Mass number - Atomic number
109
What is an isotope?
Atoms of the same element with the same number of protons but different numbers of neutrons
110
What is the electronic structure of nitrogen?
2, 5 (2 electrons in first shell, 5 in second shell)
111
What is the electronic structure of magnesium?
2, 8, 2 (2 electrons in first shell, 8 in second, 2 in third)
112
What is the electronic structure of argon?
2, 8, 8 (2 electrons in first shell, 8 in second, 8 in third)
113
What are ions?
Charged particles formed when atoms lose or gain electrons
114
What happens when atoms gain electrons?
They become negatively charged ions
115
What happens when atoms lose electrons?
They become positively charged ions
116
How do metals form ions?
They lose outer electrons to become positively charged
117
Why do Group 1 metals form +1 ions?
They have 1 electron in outer shell, lose this to get full outer shell
118
Give examples of Group 1 metal ions
Li⁺, Na⁺, K⁺
119
How do non-metals form ions?
They gain electrons on outer shell to become negatively charged
120
Why do Group 7 elements form -1 ions?
They have 7 electrons in outer shell, gain 1 more to have full outer shell (8)
121
Give examples of Group 7 ions
Cl⁻, Br⁻, F⁻
122
Element with 15 protons and 18 electrons has what ion charge?
3- (gained 3 electrons)
123
Element with 20 protons and 18 electrons has what ion charge?
2+ (lost 2 electrons)
124
Element with 12 protons and ion charge 2+ has how many electrons?
10 electrons
125
Element with ion charge 1+ and 2 electrons has how many protons?
3 protons (Li⁺)
126
Element with 10 electrons and ion charge 1- has how many protons?
9 protons (F⁻)
127
Element with 37 protons and ion charge 1+ has how many electrons?
36 electrons (K⁺)
128
Element with 9 electrons and ion charge 3+ has how many protons?
12 protons (Al³⁺)
129
Element with 35 protons and ion charge 1- has how many electrons?
36 electrons (Br⁻)
130
What similarity exists between ion electron structure and noble gases?
Ions have the same electron configuration as the nearest noble gas (stable full outer shell)
131
What comes first when naming compounds?
Metal written before the non-metal
132
What ending do compounds with metal and one non-metal have?
Non-metal ends with -ide (e.g. sodium chloride)
133
What ending do compounds with metal, non-metal and oxygen have?
Non-metal ends with -ate (e.g. sodium chlorate)
134
What is the name of MgO?
Magnesium oxide
135
What is the name of MgCl₂?
Magnesium chloride
136
What is the name of CuSO₄?
Copper sulphate
137
What is the name of LiNO₃?
Lithium nitrate
138
What is the name of Al₂(SO₄)₃?
Aluminium sulphate
139
What is the name of Na₂O?
Sodium oxide
140
What are positive ions called?
Cations
141
What are negative ions called?
Anions
142
Why must compounds be molten or dissolved for electrolysis?
So the ions are free to move (not held in fixed positions)
143
Where do positive ions move during electrolysis?
To the negative electrode (cathode)
144
Where do negative ions move during electrolysis?
To the positive electrode (anode)
145
What happens at the cathode (negative electrode)?
Positive ions gain electrons (reduction)
146
What happens at the anode (positive electrode)?
Negative ions lose electrons (oxidation)
147
What is formed at the cathode in electrolysis of molten lithium oxide?
Lithium metal
148
What is formed at the anode in electrolysis of molten lithium oxide?
Oxygen gas
149
What is formed at the cathode in electrolysis of molten copper chloride?
Copper metal
150
What is formed at the anode in electrolysis of molten copper chloride?
Chlorine gas
151
What is formed at the cathode in electrolysis of molten sodium oxide?
Sodium metal
152
What is formed at the anode in electrolysis of molten sodium oxide?
Oxygen gas
153
What is the process called when ions gain electrons?
Reduction
154
What is the process called when ions lose electrons?
Oxidation
155
What will happen to temperature of a substance gaining energy?
It will increase
156
What will happen to temperature of a substance releasing energy?
It will decrease
157
What happens to temperature of a solid as it melts?
It will stay the same
158
What type of reaction releases energy to the environment?
Exothermic
159
What type of reaction takes energy from the environment?
Endothermic
160
In an exothermic reaction does temperature go up or down?
Up
161
In an endothermic reaction does temperature go up or down?
Down
162
Give two examples of exothermic reactions
Combustion and neutralization
163
Give two examples of endothermic reactions
Thermal decomposition and photosynthesis
164
Is breaking bonds endothermic or exothermic?
Endothermic (requires energy input)
165
Is making bonds endothermic or exothermic?
Exothermic (releases energy)
166
A reaction starts at 20°C and ends at 31°C - is this endothermic or exothermic?
Exothermic (temperature increased)
167
A reaction starts at 22°C and ends at 18°C - is this endothermic or exothermic?
Endothermic (temperature decreased)
168
A reaction starts at 21°C and ends at 25°C - is this endothermic or exothermic?
Exothermic (temperature increased)
169
Which has the largest energy change: 20→31°C, 22→18°C, or 21→25°C?
20→31°C (11°C change)
170
What is the maximum number of electrons in the first shell?
2
171
What is the maximum number of electrons in the second shell?
8
172
What is the maximum number of electrons in the third shell?
8
173
What charge does a proton have?
Positive (+1)
174
What charge does a neutron have?
No charge (0)
175
What charge does an electron have?
Negative (-1)
176
Where are protons found in an atom?
In the nucleus
177
Where are neutrons found in an atom?
In the nucleus
178
Where are electrons found in an atom?
In shells around the nucleus
179
What is the relative mass of a proton?
1
180
What is the relative mass of a neutron?
1
181
What is the relative mass of an electron?
Very small (approximately 1/1840)
182
Why do Group 2 metals form 2+ ions?
They have 2 electrons in outer shell, lose both to get full outer shell
183
Why do Group 6 non-metals form 2- ions?
They have 6 electrons in outer shell, gain 2 more to have full outer shell (8)
184
What is the electronic structure of a lithium ion (Li⁺)?
2 (same as helium)
185
What is the electronic structure of a fluoride ion (F⁻)?
2, 8 (same as neon)
186
What is the electronic structure of a magnesium ion (Mg²⁺)?
2, 8 (same as neon)
187
What is the electronic structure of an oxide ion (O²⁻)?
2, 8 (same as neon)
188
What happens to electrons when a sodium atom forms a sodium ion?
Loses 1 electron from outer shell
189
What happens to electrons when a chlorine atom forms a chloride ion?
Gains 1 electron in outer shell
190
Which is more reactive: potassium or sodium?
Potassium (higher in reactivity series)
191
Which is more reactive: magnesium or zinc?
Magnesium (higher in reactivity series)
192
Which is more reactive: iron or copper?
Iron (higher in reactivity series)
193
Can zinc displace copper from copper sulfate?
Yes (zinc is more reactive than copper)
194
Can copper displace zinc from zinc sulfate?
No (copper is less reactive than zinc)
195
What happens when a more reactive metal is added to a compound of a less reactive metal?
Displacement reaction occurs - more reactive metal displaces the less reactive one
196
What products are formed when sodium reacts with oxygen?
Sodium oxide
197
What products are formed when magnesium reacts with oxygen?
Magnesium oxide
198
What products are formed when iron reacts with oxygen?
Iron oxide (Fe₂O₃)
199
What products are formed when potassium reacts with water?
Potassium hydroxide and hydrogen
200
What products are formed when calcium reacts with water?
Calcium hydroxide and hydrogen
201
What products are formed when zinc reacts with hydrochloric acid?
Zinc chloride and hydrogen
202
What products are formed when magnesium reacts with sulfuric acid?
Magnesium sulfate and hydrogen
203
What products are formed when iron reacts with hydrochloric acid?
Iron chloride and hydrogen
204
Do all metals react with oxygen?
No - some very unreactive metals like gold and platinum don't react
205
Do all metals react with water?
No - only the most reactive metals react with water
206
Do all metals react with acids?
No - metals below hydrogen in the reactivity series don't react with acids
207
What is the reactivity series order (most to least reactive)?
Potassium, Sodium, Calcium, Magnesium, Aluminium, Zinc, Iron, Tin, Lead, Copper, Silver, Gold, Platinum
208
Which metals react with cold water?
Potassium, Sodium, Calcium
209
Which metals react with steam only?
Magnesium, Aluminium, Zinc, Iron
210
Which metals don't react with water at all?
Tin, Lead, Copper, Silver, Gold, Platinum
211
What is the test for metal reactivity with oxygen?
How vigorously the metal burns and brightness of flame
212
What is the test for metal reactivity with water?
How vigorously the metal reacts and how much hydrogen is produced
213
What is the test for metal reactivity with acid?
How vigorously the metal reacts and how much hydrogen is produced
214
What is a physical change?
A change where no new substances are formed and the change is reversible
215
What is a chemical change?
A change where new substances are formed and the change is usually irreversible
216
Give an example of a physical change
Melting ice, dissolving sugar, boiling water
217
Give an example of a chemical change
Burning wood, rusting iron, cooking an egg
218
What is the difference between an atom and an ion?
An atom is neutral, an ion is charged due to loss or gain of electrons
219
What is the difference between a cation and an anion?
Cation is positively charged, anion is negatively charged
220
What does the term "malleable" mean?
Can be hammered into thin sheets
221
What does the term "ductile" mean?
Can be drawn out into thin wires
222
What does the term "brittle" mean?
Breaks easily when hammered or bent
223
What is thermal conductivity?
The ability to conduct heat
224
What is electrical conductivity?
The ability to conduct electricity
225
Why do metals conduct electricity?
They have free electrons that can move through the metal
226
Why don't non-metals conduct electricity?
Their electrons are held tightly and cannot move freely
227
What is an exception to non-metals not conducting electricity?
Graphite (a form of carbon) conducts electricity
228
What is the pH of a neutral solution?
7
229
What is the pH range for acids?
Less than 7 (0-6)
230
What is the pH range for alkalis?
Greater than 7 (8-14)
231
What color does universal indicator turn in acid?
Red/orange (strong acid) or yellow (weak acid)
232
What color does universal indicator turn in neutral solution?
Green
233
What color does universal indicator turn in alkali?
Blue (weak alkali) or purple (strong alkali)
234
What color does litmus paper turn in acid?
Red
235
What color does litmus paper turn in alkali?
Blue
236
What happens when an acid reacts with a base?
Neutralization occurs - salt and water are formed
237
What is the word equation for neutralization?
Acid + Base → Salt + Water
238
Give an example of a strong acid
Hydrochloric acid, sulfuric acid, nitric acid
239
Give an example of a weak acid
Ethanoic acid (vinegar), citric acid
240
Give an example of a strong alkali
Sodium hydroxide, potassium hydroxide
241
Give an example of a weak alkali
Ammonia solution
242
What is the formula for hydrochloric acid?
HCl
243
What is the formula for sulfuric acid?
H₂SO₄
244
What is the formula for nitric acid?
HNO₃
245
What is the formula for sodium hydroxide?
NaOH
246
What is the formula for calcium hydroxide?
Ca(OH)₂
247
What is produced when zinc reacts with copper sulfate?
Zinc sulfate and copper
248
What is produced when iron reacts with copper sulfate?
Iron sulfate and copper
249
What is produced when magnesium reacts with zinc sulfate?
Magnesium sulfate and zinc
250
Why does zinc displace copper from copper sulfate?
Zinc is more reactive than copper
251
Why can't copper displace zinc from zinc sulfate?
Copper is less reactive than zinc
252
What is an ore?
A rock that contains enough metal to make extraction worthwhile
253
How are very reactive metals like sodium extracted?
By electrolysis
254
How are moderately reactive metals like iron extracted?
By reduction with carbon in a blast furnace
255
How are unreactive metals like gold found?
As pure metals in the ground
256
What is reduction?
Removal of oxygen from a compound or gain of electrons
257
What is oxidation?
Addition of oxygen to a substance or loss of electrons
258
In the reaction Mg + CuO → MgO + Cu, what is oxidized?
Magnesium (gains oxygen)
259
In the reaction Mg + CuO → MgO + Cu, what is reduced?
Copper oxide (loses oxygen)
260
What does OIL RIG stand for?
Oxidation Is Loss (of electrons), Reduction Is Gain (of electrons)
261
What is a catalyst?
A substance that speeds up a chemical reaction without being used up
262
Give an example of a catalyst
Iron in the Haber process, platinum in catalytic converters
263
What is the difference between endothermic and exothermic in terms of energy?
Endothermic takes in energy, exothermic releases energy
264
What happens to the surroundings in an exothermic reaction?
They get warmer
265
What happens to the surroundings in an endothermic reaction?
They get cooler
266
What is activation energy?
The minimum energy needed for a reaction to start
267
How does a catalyst affect activation energy?
It lowers the activation energy
268
What is a reversible reaction?
A reaction where the products can react to form the original reactants
269
Give an example of a reversible reaction
Heating copper sulfate crystals and adding water back
270
What symbol is used for reversible reactions?
⇌ (double arrow)
271
What is dynamic equilibrium?
When the forward and backward reaction rates are equal
272
What happens to equilibrium if you increase temperature for an exothermic reaction?
Equilibrium shifts to the left (favors reactants)
273
What happens to equilibrium if you increase pressure for a reaction with fewer gas molecules on the right?
Equilibrium shifts to the right (favors products)
274
What is Le Chatelier's Principle?
If conditions change, equilibrium shifts to oppose the change
275
What is a pure substance?
A substance containing only one type of element or compound
276
What is chromatography used for?
Separating mixtures of substances
277
What is distillation used for?
Separating liquids with different boiling points
278
What is filtration used for?
Separating insoluble solids from liquids
279
What is crystallization used for?
Obtaining pure solid crystals from a solution
280
What is the test for chlorine gas?
Bleaches damp litmus paper
281
What is the test for oxygen gas?
Relights a glowing splint
282
What is the test for ammonia gas?
Turns damp red litmus paper blue
283
What color flame does sodium produce?
Yellow/orange
284
What color flame does potassium produce?
Lilac/purple
285
What color flame does calcium produce?
Brick red
286
What color flame does copper produce?
Blue-green
287
What is the test for sulfate ions?
Add barium chloride solution - white precipitate forms
288
What is the test for chloride ions?
Add silver nitrate solution - white precipitate forms
289
What is the test for carbonate ions?
Add acid - carbon dioxide gas is produced
290
What happens when you add sodium hydroxide to iron(II) ions?
Green precipitate forms
291
What happens when you add sodium hydroxide to iron(III) ions?
Brown precipitate forms
292
What happens when you add sodium hydroxide to copper ions?
Blue precipitate forms
293
What happens when you add sodium hydroxide to aluminum ions?
White precipitate forms (dissolves in excess)
294
What is the relative atomic mass?
The average mass of atoms of an element compared to 1/12 of carbon-12
295
What is the relative molecular mass?
The sum of relative atomic masses in a molecule
296
What is a mole?
6.02 × 10²³ particles of a substance
297
What is Avogadro's number?
6.02 × 10²³
298
How do you calculate number of moles?
Mass ÷ Relative atomic/molecular mass
299
What is the molar mass of water (H₂O)?
18 g/mol (1×2 + 16×1)
300
What is the molar mass of carbon dioxide (CO₂)?
44 g/mol (12×1 + 16×2)
301
What is the molar mass of methane (CH₄)?
16 g/mol (12×1 + 1×4)
302
What volume does 1 mole of any gas occupy at room temperature and pressure?
24 dm³ or 24,000 cm³
303
How do you calculate the volume of a gas?
Moles × 24 dm³
304
What is percentage yield?
Actual yield ÷ Theoretical yield × 100%
305
Why is percentage yield often less than 100%?
Due to incomplete reactions, side reactions, or loss during transfer
306
What is atom economy?
Mass of desired product ÷ Mass of all products × 100%
307
Why is high atom economy important?
Less waste is produced, more sustainable
308
What is concentration?
The amount of solute dissolved in a given volume of solution
309
What are the units of concentration?
g/dm³ or mol/dm³
310
How do you calculate concentration?
Mass of solute ÷ Volume of solution
311
What is a standard solution?
A solution of known concentration
312
What is a titration?
A method to find the concentration of a solution by reacting it with a solution of known concentration
313
What is the end point of a titration?
The point where the reaction is just complete
314
What is an indicator?
A substance that changes color to show the end point of a titration
315
Give an example of an indicator used in acid-base titrations
Methyl orange, phenolphthalein
316
What color is phenolphthalein in acid?
Colorless
317
What color is phenolphthalein in alkali?
Pink
318
What color is methyl orange in acid?
Red
319
What color is methyl orange in alkali?
Yellow
320
What is a burette used for?
Measuring and delivering variable volumes of liquid accurately
321
What is a pipette used for?
Measuring and transferring fixed volumes of liquid accurately
322
What is a conical flask used for in titrations?
To hold the solution being titrated
323
Why do you swirl the flask during titration?
To ensure complete mixing of the solutions
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Why do you wash the sides of the flask with distilled water during titration?
To ensure all reactants are in the solution
