Chem 121 predicting products of chemical reactions

CHEM 121 - General Chemistry I

CHEM 121 Solutions can be bought here.

Please contact Grafa before buying the answers.

If you need just several files - contact Grafa to negotiate the price.

Course description:

This 5‐credit course provides an introduction to the qualitative and quantitative principles of chemistry for non‐science majors and students enrolled in two‐year allied health science programs (Nursing, Dental Hygiene, Respiratory Care, etc. This course covers the following topics: the scientific method, measurements and the metric system, dimensional analysis and problem‐solving, matter and energy, atomic theory, chemical bonding and intermolecular forces, chemical nomenclature, chemical reactions, stoichiometry, solutions and concentration, acid‐base reactions and pH, reaction rates, equilibrium, and nuclear chemistry. This 5‐credit course includes a 3‐hour laboratory component.

1. GENERAL SCIENCE, LABORATORY SCIENCE, AND MICROSCALE

• Apply the scientific method and use empirical data and observations to construct a

sound scientific explanation.

• Distinguish between macroscopic observables and the underlying microscopic

properties of matter by interpreting and representing matter using molecular‐level

drawings.

• Develop good laboratory practices in conducting experiments and reporting

experimental results (including the proper application of significant figures, precision,

and accuracy).

2. CHEMICAL PROBLEM SOLVING

• Develop strong problem‐solving skills that are supported by basic algebraic and

numeracy skills.

• Demonstrate fluency in chemical vocabulary and symbolic representation.

• Use measurable quantities of matter to determine physical and chemical properties.

• Use stoichiometric calculations to predict quantities.

3. ATOMS, MOLECULES AND IONS

• Describe the general structure of an atom.

• Explain the historical development of the atomic theory and the evolution of the

current modern atomic model.

• Explain the relationship between the position of an element in the periodic table and

its physical/chemical properties, including periodic trends.

• Describe the differences in the structure and properties of substances based on

different types and models of bonding.

4. STATES OF MATTER: GASES, LIQUIDS AND SOLIDS

• Compare and contrast the properties of the three states of matter.

• Use kinetic‐molecular theory to explain gas behavior.

• Describe intermolecular forces and chemical bonds and how they influence physical

and chemical properties and changes.

5. PHYSICAL AND CHEMICAL CHANGES AND REACTIONS

• Recognize and describe changes in heat and temperature associated with physical and

chemical changes.

• Classify and balance chemical reactions and predict products for different types of

reactions.

• Apply the properties of ionic and molecular substances in aqueous solution to describe

systems and predict behavior.

• Recognize what factors influence reaction rates.

• Distinguish between chemical and nuclear reactions

CHEM 121: Exam 1 Study Guide Chapter 1

• Know the Scientific method

• Know the definitions for hypothesis, scientific law, and scientific theory. Chapter 2

• Length, mass, weight, volume - Know 1 ft.≡12 in., 1 yd. ≡3 ft., 1 gal≡4 qt., 1 qt.≡2 pints, 1 pint≡2 cups

‐ Know 1 cm3≡1 mL and 1 dm3≡1 L

• Significant figures or digits ‐ Rounding ‐ In addition, subtraction ‐ In multiplication, division ‐ In measurements (uncertainty)

• Scientific notation

• Solve problems using dimensional analysis with conversion factors, showing all work

• Use dimensional analysis to solve problems

• Metric system ‐ Know these metric prefixes: kilo, deci, centi, milli, and micro ‐ Be able to perform metric‐metric

conversions using these prefixes

• Use the metric‐English conversions provided (1 in. ≡2.54 cm; 1 lb=453.6 g; 1 qt=946 mL)

• Volume by calculation ‐ Vrectangular solid = length × width × thickness

• Volume by displacement

• Density: V m

d =

‐ Be able to determine density, mass, or volume given the other two quantities

‐ Identify what items sink or float in a given liquid given the densities of the liquid and other substances.

• Temperature - Know the formulas for converting ˚F‐to‐˚C or ˚C‐

to‐˚F and K‐to‐˚C or ˚C‐to‐K

• Percentage: ratio of parts per 100 parts ‐ Given amount of part and whole, calculate % ‐ Use a given % to solve for part or whole

Chapter 3

• Know that matter is studied at the macroscopic, microscopic, particulate (molecular) levels

• Physical states of matter ‐ Determine physical state of substances (solids, liquids, gases) given descriptions of volume, shape, particles moving, etc.

• Classification of matter – Given examples, determine which are elements, compounds, or mixtures – Given molecular‐level images, determine

which are elements, compounds, or mixtures and solids, liquids, or gases

– Distinguish between homogeneous and heterogeneous mixtures

CHEM121 Exam 1 Study Guide F2012 page 2 of 4

Chapter 3 (Continued)

• Be able to identify properties and changes as physical or chemical

‐ Know terms for changes of state: ‐ Melting, freezing, vaporizing, condensation, sublimation, deposition

• Chemical reaction: ‐ reactants: starting materials ‐ products: substances produced in reaction

kinetic energy (KE): energy associated with an object’s motion ‐ Faster objects have higher KE.

potential energy (PE): energy due to its position or composition (chemical bonds)

heat: energy is transferred from a hotter substance to a cooler substance – Identify what lost heat and gained heat given different scenarios.

Know the relative kinetic energy of solids, liquids, and gases

Endothermic versus Exothermic changes: – endothermic: a change requiring energy – exothermic: a change that releases energy – To determine for physical changes consider if the reactants have more or less kinetic energy than the products.

– To determine for chemical changes consider if the surrounding became hotter or colder after the reaction.

• Law of Conservation of Mass ‐ Matter is neither created nor destroyed in a

chemical reaction. ‐ Solve problems conserving mass.

• Law of Conservation of Energy ‐ Know 6 forms of energy: heat, light,

chemical, electrical, mechanical, and nuclear

joule (J): SI unit of energy; 1 kJ=1000 J and 1 watt = 1 J/s

calorie (cal): energy needed to raise the temperature of 1 g of water by 1˚C

Be able to carry out calculations involving energy in J, cal, Cal, and kilowatt‐hours (kWh).

heat capacity (in J/mol⋅˚C): the amount of heat capacity necessary to raise the temperature of a given amount of substance by 1˚C

specific heat (in J/g⋅˚C): the amount of heat to raise temperature of 1 gram of a substance by 1˚C.

• Recognize that the greater the heat capacity or specific heat of a substance, the more heat energy it can absorb before its temperature begins to rise.

Chapter 4

• Know ideas of matter proposed by Democritus, Empedocles, and Aristotle.

• Know the main points of John Dalton’s Model, what was later proven wrong and why.

• Know people and discoveries associated with the discovery of protons, neutrons, electrons.

• Know Plum‐Pudding Model vs Nuclear Model.

CHEM121 Exam 1 Study Guide page 3 of 4

Chapter 4 (Continued)

• Know Rutherford’s Alpha‐Scattering Experiment and what was determined from it (atomic nucleus, atom mostly empty space, the size of an atom relative to its nucleus).

• Subatomic particles – proton (p+): +1 charge, inside nucleus – neutron (n): neutral, inside nucleus – electron (e–): –1 charge, outside nucleus

• Electrostatic force: force resulting from a charge on particles

‐ Objects w/ like charges repel one another. ‐ Objects w/ unlike charges attract each other.

• Know the names and element symbols for elements #1‐20 on the Periodic Table.

– Given the element symbol, name the element, or vice versa. Spelling counts!

• Know definitions of isotope, atomic mass

• Atomic notation:

symbol element A = number mass Z = number atomic =E

mass # (A): # of protons + # of neutrons

atomic # (Z): # of protons=# of electrons

• Determine # of protons, neutrons, and electrons for any given isotope.

• Give atomic notation for any element given element name/symbol and mass number

• Use the Periodic Table to identify the most abundant isotope of any element given its naturally occurring isotopes.

• Use the Periodic Table to identify those elements whose naturally occurring isotopes are all radioactive and unstable.

The Periodic Table column = group, family row = period, series

Representative Elements: A Group Elements Group IA: alkali metals (except H) Group IIA: alkaline earth metals Group VIIA: halogens Group VIIIA: noble gases

Transition Metals/Elements: B Group Elements

Inner Transition Elements: ‐ Elements in lanthanide and actinide series

• Metals, nonmetals, and semimetals: ‐ Know properties of metals and nonmetals ‐ Location on Periodic Table and properties

• Know which elements exist as solids, liquids, gases at room temperature (25˚C)

• Know the names and symbols for all elements included on p. 10 in the Ch. 4 lecture notes, Ti (titanium), and Sr (strontium), and uranium (U). Spelling counts!

Chapter 9

wavelength (λ): distance between peaks

frequency (ν): number of crests passing by a given point in 1 s

Wavelength (λ) is inversely related to frequency (ν) and energy (E): – As λ↑ → ν↓, Ε↓ or As λ↓ → ν↑, Ε↑

CHEM121 Exam 1 Study Guide page 4 of 4

Chapter 9 (Continued)

Electromagnetic Spectrum: – continuum of radiant energy – gamma (γ) rays to radio waves – The visible spectrum makes up a small portion – Red light at 700 nm is lower in energy than blue light at 400 nm.

Know the people and ideas associated with the Classical Model of Matter – John Dalton, JJ Thomson, Ernest Rutherford, James Maxwell

Max Planck and Quantum Theory – Planck proposed energy is absorbed and emitted as bundles = quanta

– single bundle of energy = quantum

Einstein and the Photoelectric Effect – Be able to describe the Photoelectric Effect – Experimental evidence for light existing as particles = photons

Bohr Theory of the Atom – Electrons move in quantized orbits called “energy levels” around the nucleus. – ground state: electron(s) fill the lowest energy level(s) before filling higher level(s)

– When an atom absorbs energy, electron jumps from lower energy to higher energy level.

– When an electron drops from a higher energy to lower energy level, it releases energy, in some cases as light → atomic emission spectra – Know the limitations of the Bohr Model.

Quantum model → probability of finding the electron in a given region in space → probability density = electron cloud → “shape” of atomic orbitals

Atomic Orbital Shapes – reflect the “probability density” for an electron in a given orbital – As principal energy level (n=1, 2, 3,…) increases, the orbital size increases. – Energy levels divided into sublevels (s, p, d, f) – Know the number of s, p, and d orbitals (e.g. one s, three p, five d orbitals). – Know the general shape(s) of s and p orbitals. Write electron configurations for any neutral atom of elements #1‐20. • Write using full notation and core notation (Noble Gas abbreviation)

• Know Representative Elements usually form ions that are isoelectronic with—have the same number of electrons as—a Noble Gas

core electrons: electrons belonging to filled electron shells

valence electrons: outermost electrons – The group number for each element is equal

to its number of valence electrons. – Only valence electrons are gained, lost, or

shared during chemical reactions. Be able to draw Electron Dot Symbols to represent the number of valence electrons in an individual atom.

You will be given a Periodic Table with elements symbols, atomic numbers, and atomic masses.

Be able to solve problems combining concepts covered in Chapters 1‐4 and 9.