Chemistry Flashcards
1
Q
What is the first step of the Scientific Method?
A
Observation: Identifying a phenomenon or pattern that prompts a question.
2
Q
What is hypothesis formation?
A
Developing a testable, predictive statement based on observations.
3
Q
What does experimentation involve?
A
Designing and performing tests to gather data.
4
Q
What is the purpose of analysis in the Scientific Method?
A
Using statistical and logical methods to evaluate results.
5
Q
What is the conclusion in the Scientific Method?
A
Summarizing findings and determining if they support the hypothesis.
6
Q
What is peer review?
A
Ensuring reliability through review by other scientists.
7
Q
What are some applications of science?
A
Includes medicine (e.g., drug development), environmental science (e.g., pollution control), and engineering (e.g., material innovation).
8
Q
What are ethical issues in scientific applications?
A
Cloning, genetic modification, and animal testing pose moral questions.
9
Q
How does science impact society?
A
The role of science in shaping public policy, health, and quality of life.
10
Q
What are environmental concerns related to science?
A
Considering the ecological footprint of scientific advancements.
11
Q
What is the scope limitation of science?
A
Science is limited to empirical, observable phenomena.
12
Q
What is subjectivity in science?
A
Inability to address questions about personal values or aesthetic judgments.
13
Q
What are technology constraints in scientific research?
A
Some phenomena are difficult to study due to current tech limits.
14
Q
How do economic and social factors influence science?
A
Research funding and public opinion can influence what is studied.
15
Q
What is the first step in identifying risks and hazards?
A
Identification: Recognizing possible dangers in procedures or chemicals (e.g., corrosive, toxic).
16
Q
What does probability and severity assess?
A
Assessing the likelihood of occurrence and potential impact.
17
Q
What are control measures in scientific safety?
A
Implementing safety protocols like fume hoods, gloves, and safety goggles.
18
Q
What is the importance of documentation in risk assessment?
A
Recording hazards and safety measures as part of a risk assessment.
19
Q
What is an independent variable?
A
The factor being changed.
20
Q
What is a dependent variable?
A
The measured outcome.
21
Q
What are control variables?
A
Factors kept constant to ensure valid results.
22
Q
What must hypothesis development be?
A
Specific, testable, and based on prior knowledge.
23
Q
What is critical for experiment design?
A
Randomization, control groups, and sufficient sample size are critical for validity.
24
Q
What is quantitative data?
A
Measurable data, often numerical, such as temperature or mass.
25
What is qualitative data?
Descriptive data, such as color change or texture.
26
Why is using calibrated instruments important?
Importance of using calibrated instruments (e.g., thermometers, balances).
27
What is essential for recording data?
Clear and accurate record-keeping, often in tables or lab notebooks.
28
What does data transformation involve?
Calculating averages, percentages, or changes from raw data.
29
What is statistical analysis?
Employing statistical methods to interpret data trends and significance.
30
What is error analysis?
Identifying potential errors (systematic vs. random) and their effects on results.
31
What is data interpretation?
Making sense of the results in the context of the hypothesis.
32
What are bar graphs used for?
Best for comparing discrete categories.
33
What are line graphs useful for?
Useful for showing trends over time or continuous data.
34
What do pie charts display?
Display parts of a whole, often used in percentage-based data.
35
What is important when interpreting data?
Recognizing trends, correlations, and outliers.
36
What are SI units?
Standard units for science (meters, kilograms, seconds, moles, etc.).
37
What are derived units?
Units like joules (energy) and newtons (force), based on SI units.
38
Why are unit conversions essential?
Essential for comparing data in different measurement systems (e.g., cm to m).
39
What is precision and accuracy in measurements?
Using appropriate decimal places and significant figures to reflect measurement accuracy.
40
What is conclusion drawing?
Relating results back to the hypothesis.
41
How do you evaluate reliability?
Checking if the results are consistent and repeatable.
42
What does evaluating validity involve?
Determining if the experiment accurately tests the hypothesis.
43
What are suggestions for improvement in experiments?
Identifying sources of error and how to reduce them in future experiments.
44
What do chemical equations represent?
Reactants and products: Substances before and after a reaction.
45
What is the conservation of mass?
Law stating matter cannot be created or destroyed.
46
What are balancing techniques in chemical equations?
Adding coefficients to ensure equal numbers of atoms on each side of the equation.
47
Give an example of a simple chemical reaction.
H₂ + O₂ → H₂O
## Footnote
Simple reactions like H₂ + O₂ → H₂O.
48
What are state symbols in chemical equations?
Indicating physical states: (s) for solid, (l) for liquid, (g) for gas, (aq) for aqueous solution.
49
What are ionic equations?
Only showing ions involved in the reaction, ignoring spectator ions.
50
What are half-equations?
Representing oxidation and reduction separately in redox reactions.
51
What are safety symbols?
Recognizing symbols for toxicity, flammability, corrosiveness, etc.
52
What is the purpose of Material Safety Data Sheets (MSDS)?
Information on handling, storage, and disposal of chemicals.
53
What is personal protective equipment (PPE)?
Gear like gloves, goggles, and lab coats to reduce exposure.
54
What should you do in case of chemical spills?
Follow emergency procedures for chemical spills, burns, or inhalation.
55
What is Dalton’s model of the atom?
Atoms as indivisible particles, each element unique.
56
What did Thomson’s model discover?
Discovery of the electron, leading to the 'plum pudding' model.
57
What did Rutherford’s model reveal?
Gold foil experiment revealed a dense nucleus surrounded by electrons.
58
What is the Bohr model?
Electrons orbit the nucleus in specific shells or energy levels.
59
What is the modern quantum model of the atom?
Electrons in probability clouds rather than fixed orbits.
60
What does the nucleus of an atom contain?
Contains protons (positive) and neutrons (neutral), accounting for most atomic mass.
61
What are electron shells?
Electrons (negative charge) occupy energy levels around the nucleus.
62
What is the atomic number?
Atomic number = number of protons.
63
What is the mass number?
Mass number = protons + neutrons.
64
What are isotopes?
Variants of an element with the same number of protons but different neutrons.
65
What is relative atomic mass (Ar)?
Weighted average of isotopes based on their natural abundance.
66
How is relative atomic mass calculated?
Using isotopic masses and relative abundances (e.g., for chlorine).
67
What were early attempts at creating the periodic table?
Newlands’ Law of Octaves, Mendeleev’s table ordered by atomic mass.
68
What did Mendeleev’s predictions involve?
Left gaps for undiscovered elements, predicted properties.
69
How is the modern periodic table organized?
Organized by atomic number rather than mass, which resolved issues with isotope placement.
70
What are groups and periods in the periodic table?
Vertical columns (groups) have similar properties; horizontal rows (periods) show repeating patterns.
71
Where are metals and nonmetals located on the periodic table?
Metals on the left, nonmetals on the right, separated by a 'staircase.'
72
What are trends observed in the periodic table?
Atomic size decreases across a period, reactivity varies across and down groups.
73
What do energy levels represent?
Electrons occupy specific energy levels around the nucleus.
74
What is shell notation?
Configurations written as numbers (e.g., 2,8,1 for sodium).
75
What are orbital diagrams?
More detailed representations, showing electron arrangement in s, p, d, and f orbitals.
76
Why are electronic configurations important?
Outer (valence) electrons determine reactivity and type of bonding.
77
How are ions formed?
Atoms gain or lose electrons to form stable ions (like Na⁺, Cl⁻).
78
What is electrostatic attraction?
Positive and negative ions attract each other to form ionic bonds.
79
What are common ions?
Monatomic ions (single atoms) and polyatomic ions (like NO₃⁻, SO₄²⁻).
80
What is ionic bonding?
Metals lose electrons, nonmetals gain electrons to achieve stable electron configurations.
81
What is a lattice structure?
Ions arranged in a repeating 3D pattern, maximizing attraction and minimizing repulsion.
82
What are properties of ionic compounds?
High melting/boiling points, solubility in water, conductivity when melted or dissolved.
83
What are properties of ionic solids?
Brittle, high melting point due to strong ionic bonds.
84
How do ionic compounds behave in water?
Many dissolve in water as the ions interact with water molecules.
85
When do ionic compounds conduct electricity?
Conductive when liquid or in solution, as ions are free to move.
86
What is covalent bonding?
Nonmetals share electrons to achieve stable configurations.
87
What are single, double, and triple bonds?
Number of shared electron pairs (e.g., H₂O has two single bonds).
88
What does VSEPR theory predict?
Shapes based on electron repulsion (e.g., tetrahedral for methane).
89
What are intermolecular forces?
Weak forces between molecules (e.g., Van der Waals, hydrogen bonds).
90
What are properties of simple molecular substances?
Low melting/boiling points, do not conduct electricity.
91
Give examples of simple molecular substances.
Water (H₂O), methane (CH₄), carbon dioxide (CO₂).
92
What are giant covalent structures?
Large, lattice-like structures (e.g., diamond, graphite).
93
What are the properties of giant covalent structures?
Extremely high melting points, hard (diamond) or soft (graphite).
94
How are atoms bonded in giant covalent structures?
Every atom covalently bonded to others in a network.
95
What is the electron sea model?
Valence electrons are free to move among metal cations.
96
What are properties of metals?
Conductivity, malleability, ductility due to mobile electrons.
97
Give examples of metals.
Copper, iron, aluminum.
98
What are the states of matter?
Solid, Liquid, Gas: Distinct properties due to particle arrangement and movement.
99
What are changes of state?
Melting, freezing, condensation, and sublimation.
100
What does the kinetic theory describe?
Describes behavior of particles in different states.
101
What is a pure substance?
A material with only one type of particle (element or compound), with a sharp melting/boiling point.
102
What effect do impurities have on melting points?
Lower melting points and broadened melting ranges; impurities in boiling increase the boiling point.
103
How can purity be tested?
Using melting/boiling point data to identify pure substances versus mixtures.
104
What is simple distillation?
Separates a solvent from a solution (e.g., water from salt water) by boiling and condensation.
105
What is fractional distillation?
Separates mixtures of liquids with different boiling points, such as crude oil.
106
What is the application of distillation?
Used in industries and laboratories for purifying substances or separating liquid mixtures.
107
What is filtration?
Separates an insoluble solid from a liquid using a porous barrier (e.g., sand from water).
108
What is crystallization?
Separates a soluble solid from a solution by evaporating the solvent to leave crystals (e.g., salt from seawater).
109
What is important when choosing a separation method?
Deciding based on physical properties like solubility, boiling point, or particle size.
110
What techniques are used for separation?
Filtration, distillation, and chromatography depending on whether the mixture is homogeneous or heterogeneous.
111
What is paper chromatography?
Components of a mixture separate based on solubility and interaction with a stationary phase (paper) and mobile phase (solvent).
112
What is the Rf value?
Ratio of distance traveled by substance to distance traveled by solvent; helps identify substances.
113
What are applications of chromatography?
Used to identify dyes, inks, and other pigments by comparing Rf values with known substances.
114
How is chromatography used in analyzing ink composition?
Separates different pigments in ink, which can then be identified based on Rf values.
115
What is the importance of water treatment?
Ensuring safe drinking water by removing contaminants and pathogens.
116
What processes are involved in water treatment?
Filtration: Removes large particles. Sedimentation: Settling of heavier particles. Chlorination: Adding chlorine to kill bacteria and pathogens. Desalination: Removing salt from seawater, often using reverse osmosis for areas without fresh water sources.
117
What are the properties of acids?
Taste sour, turn blue litmus red, and have pH <7.
118
What are the properties of bases?
Taste bitter, turn red litmus blue, and have pH >7.
119
Give examples of an acid and a base.
Hydrochloric acid (HCl) as an acid; sodium hydroxide (NaOH) as a base.
120
What does the pH scale measure?
Measures acidity or alkalinity, with 7 being neutral.
121
What is a neutralization reaction?
Acid + Base → Salt + Water (e.g., HCl + NaOH → NaCl + H₂O).
122
What are applications of neutralization reactions?
Used in antacids to neutralize stomach acid, in agriculture to adjust soil pH.
123
What are indicators?
Litmus paper, phenolphthalein, and methyl orange help to visualize pH changes in these reactions.
124
What are strong acids?
Fully ionize in water (e.g., HCl, H₂SO₄), releasing more H⁺.
125
What is the general reaction type for neutralization?
Acid + Base → Salt + Water (e.g., HCl + NaOH → NaCl + H₂O).
126
What are some applications of neutralization reactions?
Used in antacids to neutralize stomach acid, in agriculture to adjust soil pH.
127
What indicators are used to visualize pH changes in acid-base reactions?
Litmus paper, phenolphthalein, and methyl orange.
128
What characterizes strong acids?
Strong acids fully ionize in water (e.g., HCl, H₂SO₄), releasing more H⁺ ions.
129
What characterizes weak acids?
Weak acids partially ionize in water (e.g., acetic acid), leading to fewer H⁺ ions in solution.
130
How do the pH levels of strong and weak acids compare?
Strong acids have lower pH compared to weak acids of the same concentration.
131
What happens when acids react with metals?
Produces salt and hydrogen gas (e.g., 2HCl + Mg → MgCl₂ + H₂).
132
What happens when acids react with metal oxides?
Produces salt and water (e.g., H₂SO₄ + CuO → CuSO₄ + H₂O).
133
What happens when acids react with metal carbonates?
Produces salt, water, and carbon dioxide (e.g., 2HCl + CaCO₃ → CaCl₂ + H₂O + CO₂).
134
What is the process of making soluble salts?
Neutralization: Mixing acid with an appropriate base or carbonate.
135
What is crystallization in the context of making soluble salts?
Evaporating water from the solution to form solid crystals of the salt.
136
What are some applications of making soluble salts?
Produces salts for use in foods, cleaning agents, and pharmaceuticals.
137
What is electrolysis?
Decomposition of compounds using electric current.
138
What occurs during the electrolysis process?
Ions move to electrodes where they gain/lose electrons, forming new substances.
139
What are examples of electrolysis?
Electrolysis of water produces hydrogen and oxygen; electrolysis of NaCl produces chlorine and sodium hydroxide.
140
What are the electrode reactions in electrolysis?
Cations move to the cathode (negative), anions to the anode (positive).
141
What determines the products of electrolysis?
Depends on reactivity of ions; e.g., in aqueous solutions, hydrogen or oxygen may be produced.
142
What are applications of electrolysis?
Extraction of metals, electroplating, and purification of metals like copper.
143
How does electrolysis of copper sulfate work?
Electrodes of copper used in a copper sulfate solution, with copper ions plating onto the cathode.
144
What are the applications of electrolysis of copper sulfate?
Used in electroplating industries to coat objects with a layer of copper.
145
What happens during the purification of copper?
Impurities are left behind as sludge while pure copper is deposited.
146
What is oxidation?
Loss of electrons.
147
What is reduction?
Gain of electrons.
148
What are redox reactions?
Involves both oxidation and reduction; critical in metal extraction and battery chemistry.
149
What are applications of redox reactions?
Used in processes like corrosion prevention and electroplating.
150
What is the reactivity series?
Metals arranged by their tendency to lose electrons.
151
Which metals are highly reactive?
Potassium, sodium, calcium.
152
Which metals are very unreactive?
Gold and platinum.
153
How does reactivity affect extraction methods?
Reactive metals need electrolysis, while less reactive metals can be extracted by reduction.
154
What is a displacement reaction?
A more reactive metal displaces a less reactive metal from its compound (e.g., Zn + CuSO₄ → ZnSO₄ + Cu).
155
What is the redox aspect of displacement reactions?
One substance is oxidized, the other is reduced.
156
What are the uses of displacement reactions?
Used to obtain metals from their compounds and in galvanic cells.
157
What methods are used to extract metals from their ores?
Reduction with carbon for metals like iron, electrolysis for more reactive metals like aluminum.
158
What is a blast furnace used for?
Used for iron extraction, where carbon reduces iron oxide to produce iron.
159
What is the environmental impact of mining and extraction?
Can lead to pollution and habitat destruction.
160
How are metals like aluminum extracted?
From molten salts via electrolysis.
161
What are the requirements for extracting metals via electrolysis?
High energy due to high temperatures needed to melt the ores.
162
What are alternative methods of extracting metals?
Phytomining and bioleaching.
163
What is phytomining?
Uses plants to absorb metal ions from soil, then harvests and burns them to extract metals.
164
What is bioleaching?
Uses bacteria to extract metals from low-grade ores.
165
What are the advantages of alternative extraction methods?
More sustainable and less energy-intensive than traditional methods.
166
What is the importance of recycling metals?
Reduces need for new raw materials, conserves resources, and lowers environmental impact.
167
What processes are involved in recycling metals?
Metals are melted down and reformed into new products.
168
What are the benefits of recycling metals?
Saves energy compared to extracting metals from ores and reduces landfill waste.
169
What is a life cycle assessment?
Evaluates environmental impact of products from production to disposal.
170
What considerations are included in a life cycle assessment?
Raw material extraction, energy consumption, transportation, and waste management.
171
How do life cycle assessments help companies?
Helps companies make sustainable choices and improve product designs.
172
What are reversible reactions?
Reactions that can proceed in both directions (forward and reverse), symbolized by a double arrow (⇌).
173
What is dynamic equilibrium?
In a closed system, forward and reverse reactions occur at the same rate, leading to a stable concentration of reactants and products.
174
What is an example of a reversible reaction?
The Haber process (N₂ + 3H₂ ⇌ 2NH₃) is a key industrial example.
175
What is Le Chatelier’s Principle?
If a system at equilibrium experiences a change in concentration, pressure, or temperature, the equilibrium will shift to counteract the change.
176
What happens to equilibrium when reactants are increased?
Shifts equilibrium to the right (favoring products).
177
What happens to equilibrium when products are added?
Shifts equilibrium to the left.
178
What happens to equilibrium when pressure is increased?
Favors the side with fewer gas molecules.
179
What happens to equilibrium when temperature is increased?
Favors the endothermic reaction (absorbing heat).
180
What are applications of Le Chatelier’s Principle?
Used in chemical industries to maximize yields, such as in the synthesis of ammonia or sulfuric acid.
181
What are qualitative tests in chemical analysis?
Flame tests, precipitation reactions, and identification of gases.
182
What do flame tests identify?
Metal ions based on flame color (e.g., sodium produces a yellow flame).
183
What are precipitation reactions used for?
To react specific ions to form characteristic precipitates.
184
What are some tests for identifying gases?
The “pop” test for hydrogen, limewater test for carbon dioxide, and damp litmus test for chlorine.
185
What are the advantages of instrumental methods in chemical analysis?
More accurate, faster, and sensitive compared to traditional methods.
186
What is mass spectrometry used for?
Determines molecular mass and structure.
187
What does infrared spectroscopy identify?
Functional groups in organic molecules.
188
What is chromatography used for?
Separates mixtures and identifies components, useful in forensic science and environmental analysis.
189
What is relative atomic mass (Ar)?
Weighted average mass of an atom compared to 1/12 of a carbon-12 atom.
190
What is relative formula mass (Mr)?
Sum of the relative atomic masses in a compound’s formula.
191
How is relative mass used in calculations?
To determine the mass of compounds in chemical reactions and predict product quantities.
192
What is the law of conservation of mass?
In a closed system, mass remains constant in chemical reactions.
193
What are the implications of the conservation of mass?
The mass of products equals the mass of reactants.
194
How does conservation of mass apply to balancing equations?
Helps ensure that all atoms are accounted for in the products.
195
What is an empirical formula?
The simplest whole-number ratio of elements in a compound.
196
How do you calculate empirical formulae?
Divide the moles of each element by the smallest mole value to find ratios.
197
What is concentration in chemistry?
Amount of solute per unit volume of solution, usually expressed in moles per liter (mol/L).
198
How is concentration calculated?
Concentration = Amount of solute / Volume of solution.
199
What is the importance of concentration calculations?
Important for calculating reactants needed in reactions and preparing solutions in labs.
200
How do you calculate masses from equations?
Using balanced equations to relate moles of reactants to moles of products.
201
What is stoichiometry?
Essential in predicting product amounts and ensuring reactants are used efficiently.
202
What is the definition of a mole?
One mole contains 6.02 *10^23 particles (Avogadro’s number).
203
What is molar mass?
Mass of one mole of a substance, equal to the relative formula mass in grams.
204
How are conversions between grams, moles, and particles done?
Using molar mass and Avogadro’s number.
205
What are mole ratios?
Based on balanced chemical equations to determine the proportions of reactants and products.
206
What is a limiting reactant?
The reactant that is completely consumed first, determining the maximum amount of product formed.
207
How do you calculate theoretical yield?
Calculate moles of reactants/products to find theoretical yield and compare with actual yield.
