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Stoichiometry


 * Chemistry S2 Syllabus**

** Chemistry S2 Course Objectives **

Relate the structure, behavior, and scale of an atom to the particles that compose it
 * 1) Discriminate between the relative size, charge, and position of protons, neutrons, and electrons in the atom.
 * 2) Generalize the relationship of proton number to the element’s identity.
 * 3) Relate the mass and number of atoms to the gram-sized quantities of matter in a mole.

Correlate atomic structure and the physical and chemical properties of an element to the position of the element on the periodic table.
 * 1) Use the periodic table to correlate the number of protons, neutrons, and electrons in an atom.
 * 2) Compare the number of protons and neutrons in isotopes of the same element.
 * 3) Identify similarities in chemical behavior of elements within a group.
 * 4) Generalize trends in reactivity of elements within a group to trends in other groups.
 * 5) Compare the properties of elements (e.g., metal, nonmetallic, metalloid) based on their position in the periodic table.

Science language students should use//: atom, element, nucleus, proton, neutron, electron, isotope, metal, nonmetal, metalloid, periodic table, mole //


 * Atoms form bonds with other atoms by transferring or sharing electrons. The arrangement of electrons in an atom, particularly the valence electrons, determines how an atom can interact with other atoms. **
 * The types of chemical bonds holding them together determine many of the physical properties of compounds. The formation of compounds results in a great diversity of matter from a limited number of elements. **

Analyze the relationship between the valence (outermost) electrons of an atom and the type of bond formed between atoms.
 * 1) Determine the number of valence electrons in atoms using the periodic table.
 * 2) Predict the charge an atom will acquire when it forms an ion by gaining or losing electrons.
 * 3) Predict bond types based on the behavior of valence (outermost) electrons.
 * 4) Compare covalent, ionic, and metallic bonds with respect to electron behavior and relative bond strengths.

Explain that the properties of a compound may be different from those of the elements or compounds from which it is formed.
 * 1) Use a chemical formula to represent the names of elements and numbers of atoms in a compound and recognize that the formula is unique to the specific compound.
 * 2) Compare the physical properties of a compound to the elements that form it.
 * 3) Compare the chemical properties of a compound to the elements that form it.
 * 4) Explain that combining elements in different proportions results in the formation of different compounds with different properties.
 * In a chemical reaction new substances are formed as atoms and molecules are rearranged. The concept of atoms explains the conservation of matter, since the number of atoms stays the same in a chemical reaction no matter how they are rearranged; the total mass stays the same. Although energy can be absorbed or released in a chemical reaction, the total amount of energy and matter in it remains constant. Many reactions attain a state of equilibrium. Many ordinary activities, such as baking, involve chemical reactions. **
 * The rate of chemical reactions of atoms and molecules depends upon how often they encounter one another, which is a function of concentration, temperature, and pressure of the reacting materials. Catalysts can be used to change the rate of chemical reactions. Under proper conditions reactions may attain a state of equilibrium. **

Identify evidence of chemical reactions and demonstrate how chemical equations are used to describe them.
 * 1) Generalize evidences of chemical reactions.
 * 2) Compare the properties of reactants to the properties of products in a chemical reaction.
 * 3) Use a chemical equation to describe a simple chemical reaction.
 * 4) Recognize that the number of atoms in a chemical reaction does not change.
 * 5) Determine the molar proportions of the reactants and products in a balanced chemical reaction.
 * 6) Investigate everyday chemical reactions that occur in a student's home (e.g., baking, rusting, bleaching, cleaning).

Analyze evidence for the laws of conservation of mass and conservation of energy in chemical reactions.
 * 1) Use molar relationships in a balanced chemical reaction to predict the mass of product produced in a simple chemical reaction that goes to completion.
 * 2) After observing or measuring, classify evidence of temperature change in a chemical reaction as endothermic or exothermic.

Evaluate factors specific to collisions (e.g., temperature, particle size, concentration, and catalysts) that affect the rate of chemical reaction.
 * 1) Design and conduct an investigation of the factors affecting reaction rate and use the findings to generalize the results to other reactions.
 * 2) Use information from graphs to draw warranted conclusions about reaction rates.
 * 3) Correlate frequency and energy of collisions to reaction rate.
 * 4) Identify that catalysts are effective in increasing reaction rates.

Recognize that certain reactions do not convert all reactants to products, but achieve a state of dynamic equilibrium that can be changed.
 * 1) Explain the concept of dynamic equilibrium.
 * 2) Given an equation, identify the effect of adding either product or reactant to a shift in equilibrium.
 * 3) Indicate the effect of a temperature change on the equilibrium, using an equation showing a heat term.

Science language students should use//: chemical reaction, matter, law of conservation of mass, law of conservation of energy, temperature, electrochemical cell, entropy, chemical equation, endothermic, exothermic, heat, rate, catalyst, concentration, collision theory, equilibrium, half reaction //

**Solutions make up many of the ordinary substances encountered in everyday life.**
 * The relative amounts of solutes and solvents determine the concentration and the physical properties of a solution. Two important categories of solutions are acids and bases. **.

Describe factors affecting the process of dissolving and evaluate the effects that changes in concentration have on solutions.
 * 1) Use the terms solute and solvent in describing a solution.
 * 2) Sketch a solution at the particle level.
 * 3) Describe the relative amount of solute particles in concentrated and dilute solutions and express concentration in terms of molarity and molality.

Summarize the quantitative and qualitative effects of colligative properties on a solution when a solute is added.
 * 1) Identify the colligative properties of a solution.
 * 2) Measure change in boiling and/or freezing point of a solvent when a solute is added.
 * 3) Describe how colligative properties affect the behavior of solutions in everyday applications (e.g., road salt, cold packs, antifreeze).

Differentiate between acids and bases in terms of hydrogen ion concentration.
 * 1) Relate hydrogen ion concentration to pH values and to the terms acidic, basic or neutral.
 * 2) Using an indicator, measure the pH of common household solutions and standard laboratory solutions, and identify them as acids or bases.
 * 3) Determine the concentration of an acid or a base using a simple acid-base titration.
 * 4) Research and report on the uses of acids and bases in industry, agriculture, medicine, mining, manufacturing, or construction.
 * 5) Evaluate mechanisms by which pollutants modify the pH of various environments (e.g., aquatic, atmospheric, soil).

Science language students should use//: solution, solute, solvent, concentration, molarity, percent concentration, colligative property, boiling point, freezing point, acid, base, pH, indicator, titration, hydrogen ion, neutralization, parts per million, concentrated, dilute, dissolve //