chemistry unit 4 ppt

ChemistryToombs County High School

Energy is related to molecular motion, endothermic and exothermic processes, and the states of matter interrelated in chemical reactions.

How does the quantity of energy impact the rate of reactions?

SC2.Students will relate how the Law of Conservation of Matter is used to determine chemical composition in compounds and chemical reactions.

c) Apply concepts of the mole and Avogadro’s number to conceptualize and calculate molar volumes of gases.

d) Identify and solve different types of stoichiometry problems, specifically relating mass to moles and mass to mass.

e) Demonstrate the conceptual principle of limiting reactants.

SC2 Students will relate how the Law of Conservation of Matter is used to determine chemical composition in compounds and chemical reactions.

If a carpenter had two tabletops and seven table legs, he could only build one four-legged table. The number of table legs is the limiting factor in the construction of four-legged tables. Similarly, in chemistry, the amount of product made in a chemical reaction may be limited by the amount of one or more of the reactants.

12.3

Limiting and Excess ReagentsHow is the amount of product in a reaction affected by an insufficient quantity of any of the reactants?

12.3

▪ In a chemical reaction, an insufficient quantity of any of the reactants will limit the amount of product that forms. ▪The limiting reagent is the reagent that determines the amount of product that can be formed by a reaction.

12.3

▪ In the reaction of nitrogen and hydrogen, hydrogen is the limiting reagent. Nitrogen is the reagent that is not completely used up in the reaction. The reagent that is not used up is called the excess reagent.

12.3

12.3

The Chemical Equation for the Preparation of Ammonia

Problem Solving 12.25 Solve Problem 25 with the help of an interactive guided tutorial.

Percent Yield What does the percent yield of a

reaction measure?

12.3

▪ The percent yield is a measure of the efficiency of a reaction carried out in the laboratory.

▪ A batting average is actually a percent yield.

12.3

▪The theoretical yield is the maximum amount of product that could be formed from given amounts of reactants.

▪ In contrast, the amount of product that actually forms when the reaction is carried out in the laboratory is called the actual yield.

12.3

▪ The percent yield is the ratio of the actual yield to the theoretical yield expressed as a percent.

12.3

END OF SHOW

SC7.Students will characterize the properties that describe solutions and the nature of acids and bases.

a) Explain the process of dissolving in terms of solute/solvent interactions: Observe factors that affect the rate at which a solute dissolves in a specific solvent, Relate molality to colligative properties.

A sinkhole forms when the roof of a cave weakens from being dissolved by groundwater and suddenly collapses. One recorded sinkhole swallowed a house, several other buildings, five cars, and a swimming pool! You will learn how the solution process occurs and the factors that influence the process.

16.1

Solution Formation What factors determine the rate at

which a substance dissolves?

16.1

▪ The compositions of the solvent and the solute determine whether a substance will dissolve. The factors that determine how fast a substance dissolves are

stirring (agitation) temperature the surface area of the dissolving particles

16.1

▪ A cube of sugar in cold tea dissolves slowly.

16.1

▪ Granulated sugar dissolves in cold water more quickly than a sugar cube, especially with stirring.

16.1

▪ Granulated sugar dissolves very quickly in hot tea.

16.1

Stirring and Solution Formation▪ Stirring speeds up the dissolving process

because fresh solvent (the water in tea) is continually brought into contact with the surface of the solute (sugar).

16.1

Temperature and Solution Formation ▪ At higher temperatures, the kinetic energy of

water molecules is greater than at lower temperatures, so they move faster. As a result, the solvent molecules collide with the surface of the sugar crystals more frequently and with more force.

16.1

Particle Size and Solution Formation▪ A spoonful of granulated sugar dissolves

more quickly than a sugar cube because the smaller particles in granulated sugar expose a much greater surface area to the colliding water molecules.

16.1

Solubility How is solubility usually expressed?

16.1

▪ A saturated solution contains the maximum amount of solute for a given quantity of solvent at a given temperature and pressure.

▪ An unsaturated solution contains less solute than a saturated solution at a given temperature and pressure.

16.1

▪ In a saturated solution, the rate of dissolving equals the rate of crystallization, so the total amount of dissolved solute remains constant.

16.1

▪ The solubility of a substance is the amount of solute that dissolves in a given quantity of a solvent at a specified temperature and pressure to produce a saturated solution.

▪ Solubility is often expressed in grams of solute per 100 g of solvent.

16.1

▪ Some liquids combine in all proportions, while others don’t mix at all. ▪ Two liquids are miscible if they dissolve in each

other in all proportions. ▪ Two liquids are immiscible if they are insoluble in

each other.

16.1

▪ Oil and water are immiscible.

16.1

▪ Vinegar and oil are immiscible.

16.1

Factors Affecting Solubility What conditions determine the amount

of solute that will dissolve in a given solvent?

16.1

Temperature affects the solubility of solid, liquid, and gaseous solutes in a solvent; both temperature and pressure affect the solubility of gaseous solutes.

16.1

Temperature ▪ The solubility of most solid substances increases as

the temperature of the solvent increases. ▪ The solubilities of most gases are greater in cold

water than in hot.

16.1

▪ The mineral deposits around hot springs result from the cooling of the hot, saturated solution of minerals emerging from the spring.

16.1

▪ A supersaturated solution contains more solute than it can theoretically hold at a given temperature.

▪ The crystallization of a supersaturated solution can be initiated if a very small crystal, called a seed crystal, of the solute is added.

16.1

▪ A supersaturated solution is clear before a seed crystal is added.

16.1

▪ Crystals begin to form in the solution immediately after the addition of a seed crystal.

16.1

▪ Excess solute crystallizes rapidly.

16.1

Simulation 20 Observe the effect of temperature on

the solubility of solids and gases in water.

Pressure▪ Changes in pressure have little effect on the

solubility of solids and liquids, but pressure strongly influences the solubility of gases.

▪ Gas solubility increases as the partial pressure of the gas above the solution increases.

16.1

▪ Henry’s law states that at a given temperature, the solubility (S) of a gas in a liquid is directly proportional to the pressure (P) of the gas above the liquid.

16.1

1. For a given substance, which of the following will NOT influence how fast it dissolves?▪ temperature▪ amount of agitation▪ molar mass▪ size of the crystals

2. The solubility of a substance is often expressed as the number of grams of solute per▪ 100 liters of solvent.▪ 1 cm3 of solvent.▪ 100 grams of solution.▪ 100 grams of solvent.

3. The solubility of a gas in a solvent is affected by▪ both temperature and pressure.▪ only pressure.▪ only temperature.▪ both pressure and agitation.

Water must be tested continually to ensure that the concentrations of contaminants do not exceed established limits. These contaminants include metals, pesticides, bacteria, and even the by-products of water treatment. You will learn how solution concentrations are calculated.

16.2

16.2

Molarity How do you calculate the molarity of a

solution?

▪ The concentration of a solution is a measure of the amount of solute that is dissolved in a given quantity of solvent. ▪ A dilute solution is one that contains a small

amount of solute. ▪ A concentrated solution contains a large amount

of solute.

16.2

▪ Molarity (M) is the number of moles of solute dissolved in one liter of solution.

▪ To calculate the molarity of a solution, divide the moles of solute by the volume of the solution.

16.2

▪ To make a 0.5-molar (0.5M) solution, first add 0.5 mol of solute to a 1-L volumetric flask half filled with distilled water.

16.2

▪ Swirl the flask carefully to dissolve the solute.

16.2

▪ Fill the flask with water exactly to the 1-L mark.

16.2


for Sample Problem 16.2

ProblemSolving 16.11 Solve Problem 11 with the help of an interactive guided tutorial.


16.2

Making Dilutions What effect does dilution have on the

total moles of solute in a solution?

Diluting a solution reduces the number of moles of solute per unit volume, but the total number of moles of solute in solution does not change.

16.2

▪ The total number of moles of solute remains unchanged upon dilution, so you can write this equation.

▪ M1 and V1 are the molarity and volume of the initial solution, and M2 and V2 are the molarity and volume of the diluted solution.

16.2

▪ Making a Dilute Solution

16.2

▪ To prepare 100 ml of 0.40M MgSO4 from a stock solution of 2.0M MgSO4, a student first measures 20 mL of the stock solution with a 20-mL pipet.

16.2

▪ She then transfers the 20 mL to a 100-mL volumetric flask.

16.2

▪ Finally she carefully adds water to the mark to make 100 mL of solution.

16.2

▪ Volume-Measuring Devices

16.2



`

Percent Solutions What are two ways to express the

percent concentration of a solution?

16.2

▪ The concentration of a solution in percent can be expressed in two ways: as the ratio of the volume of the solute to the volume of the solution or as the ratio of the mass of the solute to the mass of the solution.

16.2

Concentration in Percent (Volume/Volume)

16.2

▪ Isopropyl alcohol (2-propanol) is sold as a 91% solution. This solution consist of 91 mL of isopropyl alcohol mixed with enough water to make 100 mL of solution.

16.2

Problem-Solving 16.15 Solve Problem 15 with the help of an interactive guided tutorial.


Concentration in Percent (Mass/Mass)

16.2

1. To make a 1.00M aqueous solution of NaCl, 58.4 g of NaCl are dissolved in▪ 1.00 liter of water.▪ enough water to make 1.00 liter of solution

▪ 1.00 kg of water.▪ 100 mL of water.

2. What mass of sodium iodide (NaI) is contained in 250 mL of a 0.500M solution? ▪ 150 g▪ 75.0 g▪ 18.7 g▪ 0.50 g

3. Diluting a solution does NOT change which of the following? ▪ concentration▪ volume▪ milliliters of solvent▪ moles of solute

4. In a 2000 g solution of glucose that is labeled 5.0% (m/m), the mass of water is▪ 2000 g. ▪ 100 g. ▪ 1995 g. ▪ 1900 g.

16.4

Molality and Mole Fraction What are two ways of expressing the

concentration of a solution?

The unit molality and mole fractions are two additional ways in which chemists express the concentration of a solution.

16.4

▪ The unit molality (m) is the number of moles of solute dissolved in 1 kilogram (1000 g) of solvent. Molality is also known as molal concentration.

16.4

▪ To make a 0.500m solution of NaCl, use a balance to measure 1.000 kg of water and add 0.500 mol (29.3 g) of NaCl.

16.4

▪ Ethlylene Glycol (EG) is added to water as antifreeze.

16.4

SC7.Students will characterize the properties that describe solutions and the nature of acids and bases.

b) Compare, contrast, and evaluate the nature of acids and bases: Strong vs. weak acids/bases in terms of percent dissociation Bronsted-Lowery pH.

Bracken Cave, near San Antonio, Texas, is home to twenty to forty million bats. Visitors to the cave must protect themselves from the dangerous levels of ammonia in the cave. Ammonia is a byproduct of the bats’ urine. You will learn why ammonia is considered a base.

19.1

Properties of Acids and Bases What are the properties of acids and

bases?

19.1

Acids▪ Acids taste sour, will change the color of an

acid-base indicator, and can be strong or weak electrolytes in aqueous solution.

19.1

▪ Citrus fruits contain citric acid. Tea contains tannic acid.

19.1

Bases▪ Bases taste bitter, feel slippery, will change

the color of an acid-base indicator, and can be strong or weak electrolytes in aqueous solution.

19.1

▪ Antacids use bases to neutralize excess stomach acid. The base calcium hydroxide is a component of mortar.

19.1

Arrhenius Acids and Bases▪ How did Arrhenius define an acid and a base?

19.1

Arrhenius said that acids are hydrogen-containing compounds that ionize to yield hydrogen ions (H+) in aqueous solution. He also said that bases are compounds that ionize to yield hydroxide ions (OH–) in aqueous solution.

19.1

19.1

▪ Hydrochloric Acid

Arrhenius Acids▪ Acids that contain one ionizable hydrogen, such as

nitric acid (HNO3), are called monoprotic acids.

▪ Acids that contain two ionizable hydrogens, such as sulfuric acid (H2SO4), are called diprotic acids.

▪ Acids that contain three ionizable hydrogens, such as phosphoric acid (H3PO4) are called triprotic acids.

19.1

Arrhenius Bases▪ Hydroxide ions are one of the products of the

dissolution of an alkali metal in water.

19.1

Milk of magnesia is a base used as an antacid.

19.1

Brønsted-Lowry Acids and Bases What distinguishes an acid from a base

in the Brønsted-Lowry theory?

19.1

The Brønsted-Lowry theory defines an acid as a hydrogen-ion donor, and a base as a hydrogen-ion acceptor.

19.1

Why Ammonia is a Base

19.1

Conjugate Acids and Bases▪ A conjugate acid is the particle formed when a

base gains a hydrogen ion. ▪ A conjugate base is the particle that remains when

an acid has donated a hydrogen ion.

19.1

▪ A conjugate acid-base pair consists of two substances related by the loss or gain of a single hydrogen ion.

▪ A substance that can act as both an acid and a base is said to be amphoteric.

19.1

▪ A water molecule that gains a hydrogen ion becomes a positively charged hydronium ion (H3O+).

19.1

Lewis Acids and Bases How did Lewis define an acid and a

base?

19.1

Lewis proposed that an acid accepts a pair of electrons during a reaction, while a base donates a pair of electrons.

19.1

▪ A Lewis acid is a substance that can accept a pair of electrons to form a covalent bond.

▪ A Lewis base is a substance that can donate a pair of electrons to form a covalent bond.

19.1

Animation 25 Compare the three important definitions

of acids and bases.

Problem Solving 19.1 Solve Problem 1 with the

help of an interactive guided tutorial.

1. Which of the following is NOT a characteristic of acids? ▪ taste sour▪ are electrolytes▪ feel slippery▪ affect the color of indicators

2. Which compound is most likely to act as an Arrhenius acid? ▪ H2O

▪ NH3.

▪ NaOH.

▪ H2SO4.

3. A Lewis acid is any substance that can accept ▪ a hydronium ion.▪ a proton.▪ hydrogen.▪ a pair of electrons.

To test a diagnosis of diabetic coma, a doctor orders several tests, including the acidity of the patient’s blood. Results from this test will be expressed in units of pH. You will learn how the pH scale is used to indicate the acidity of a solution and why the pH scale is used.

19.2

Hydrogen Ions from Water▪ The reaction in which water molecules

produce ions is called the self-ionization of water.

19.2

▪ In the self-ionization of water, a proton (hydrogen ion) transfers from one water molecule to another water molecule.

19.2

Ion Product Constant for Water How are [H+] and [OH-] related in an

aqueous solution?

19.2

For aqueous solutions, the product of the hydrogen-ion concentration and the hydroxide-ion concentration equals 1.0 10-

14.

Any aqueous solution in which [H+] and [OH-] are equal is described as a neutral solution.

19.2

▪ The product of the concentrations of the hydrogen ions and hydroxide ions in water is called the ion-product constant for water (Kw).

19.2

▪ An acidic solution is one in which [H+] is greater than [OH-].

19.2

▪ Unrefined hydrochloric acid, commonly called muriatic acid, is used to clean stone buildings and swimming pools.

19.2

▪ A basic solution is one in which [H+] is less than [OH]. Basic solutions are also known as alkaline solutions.

19.2

▪ Sodium hydroxide, or lye, is commonly used as a drain cleaner.

19.2

Problem Solving 19.10 Solve Problem 10 with the help of

an interactive guided tutorial.

The pH Concept How is the hydrogen-ion concentration

used to classify a solution as neutral, acidic, or basic?

19.2

▪ The pH of a solution is the negative logarithm of the hydrogen-ion concentration.

19.2

Calculating pH

19.2

▪ A solution in which [H+] is greater than 1 10–7 M has a pH less than 7.0 and is acidic. The pH of pure water or a neutral aqueous solution is 7.0. A solution with a pH greater than 7 is basic and has a [H+] of less than 1 10–7 M.

19.2

Calculating pOH

19.2

pH and Significant Figures

19.2

Problem Solving 19.12 Solve Problem 12 with the help

of an interactive guided tutorial.

Measuring pH What is the most important

characteristic of an acid-base indicator?

19.2

An indicator is a valuable tool for measuring pH because its acid form and base form have different colors in solution.

19.2

▪ Phenolphthalein changes from colorless to pink at pH 7–9.

19.2

Problem Solving 19.15 Solve Problem 15 with the

help of an interactive guided tutorial.

Acid-Base Indicators

19.2

▪ Universal Indicators

19.2

pH Meters

19.2

1. If the [OH-] in a solution is 7.65 10-

3M, what is the [H+] of this solution?▪ 7.65 10-17M▪ 1.31 10-12M▪ 2.12M▪ 11.88M

2. The [OH-] for four solutions is given below. Which one of the solution is basic?▪ 1.0 x 10-6M▪ 1.0 x 10-8M▪ 1.0 x 10-7M▪ 1.0 x 10-14M

3. What is the pH of a solution with a hydrogen-ion concentration of 8.5 x 10-

2M?▪ 12.93▪ 8.50▪ 5.50▪ 1.07

Lemons and grapefruits have a sour taste because they contain citric acid. Sulfuric acid is a widely used industrial chemical that can quickly cause severe burns if it comes into contact with skin. You will learn why some acids are weak and some acids are strong.

19.3

Strong and Weak Acids and Bases How does the value of an acid

dissociation constant relate to the strength of an acid?

19.3

▪ An acid dissociation constant (Ka) is the ratio of the concentration of the dissociated (or ionized) form of an acid to the concentration of the undissociated (nonionized) form.

19.3

Weak acids have small Ka values. The stronger an acid is, the larger is its Ka value.

19.3

▪ Strong acids are completely ionized in aqueous solution.

▪ Weak acids ionize only slightly in aqueous solution.

19.3

▪ In general, the base dissociation constant (Kb) is the ratio of the concentration of the conjugate acid times the concentration of the hydroxide ion to the concentration of the base.

19.3

▪ Strong bases dissociate completely into metal ions and hydroxide ions in aqueous solution.

▪ Weak bases react with water to form the hydroxide ion and the conjugate acid of the base.

19.3

Calculating Dissociation Constants How can you calculate an acid

dissociation constant (Ka) of a weak acid?

19.3

To find the Ka of a weak acid or the Kb of a weak base, substitute the measured concentrations of all the substances present at equilibrium into the expression for Ka or Kb.

19.3

Acid Dissociation Constant▪ The dissociation constant, Ka, of ethanoic acid

is calculated from the equilibrium concentrations of all of the molecules and ions in the solution.

19.3

Base Dissociation Constant▪ The dissociation constant, Kb, of ammonia is

calculated from the equilibrium concentrations of all of the molecules and ions in the solution.

19.3

Concentration and Strength

19.3

Problem Solving 19.23 Solve Problem 23 with the help of

an interactive guided tutorial.

1. H2S is considered to be a weak acid because it ▪ is insoluble in water.▪ ionizes only slightly.▪ is completely ionized.▪ is dilute.

2. Calcium hydroxide, Ca(OH)2, is a strong base because it ▪ has a large Kb.

▪ has a small Kb.

▪ forms concentrated solutions.▪ is highly soluble in water.

3. If the [H+] of a 0.205M solution of phenol (C6H5OH) at 25ºC is 2.340 10-6, what is the Ka for phenol? Phenol is monoprotic. ▪ Ka = 2.67 x 10-11

▪ Ka = 1.14 x 10-5

▪ Ka = 5.48 x 10-12

▪ Ka = 1.53 x 10-3

4. The Ka of three acids is given below. (1) 5.1 10–3

(2) 4.8 10–11

(3) 6.3 10–5

Put the acids in order from the strongest acid to the weakest acid.

▪ 1, 3, 2

▪ 2, 3, 1

▪ 3, 1, 2

▪ 2, 1, 3

5. The Kb of four bases is given below. (1) 7.41 x 10-5

(2) 1.78 x 10-5

(3) 4.27 x 10-4

(4) 4.79 x 10-4

Put the bases in order from the strongest base to the weakest base.▪ 2, 3, 4, 1▪ 2, 1, 3, 4▪ 4, 3, 1, 2▪ 1, 4, 3, 2

Excess hydrochloric acid in the stomach can cause heartburn and a feeling of nausea. Antacids neutralize the stomach acid and relieve the pain of acid indigestion. You will learn what a neutralization reaction is.

19.4

Acid-Base Reactions What are the products of the reaction of

an acid with a base?

19.4

▪ In general, the reaction of an acid with a base produces water and one of a class of compounds called salts.

19.4

▪ Reactions in which an acid and a base react in an aqueous solution to produce a salt and water are generally called neutralization reactions.

19.4

Titration What is the endpoint of a titration?

19.4

▪ The process of adding a known amount of solution of known concentration to determine the concentration of another solution is called titration.▪ The point of neutralization is the end point of the

titration.

19.4

▪ When an acid and base are mixed, the equivalence point is when the number of moles of hydrogen ions equals the number of moles of hydroxide ions.

19.4

▪ The solution of known concentration is called the standard solution. ▪ Indicators are often used to determine when enough

of the standard solution has been added to neutralize the acid or base.

▪ The point at which the indicator changes color is the end point of the titration.

19.4

Acid solution with indicator

Added base is measured with a buret.

Color change shows neutralization.

19.4

Simulation 26 Simulate the titration of several acids

and bases and observe patterns in the pH at equivalence.

1. When a neutralization takes place, one of the products is always▪ carbon dioxide.▪ a salt.▪ sodium chloride.▪ a precipitate.

2. In a titration, 45.0 mL of KOH is neutralized by 75.0 mL of 0.30M HBr. What is the concentration of the KOH solution?▪ 0.18M▪ 0.60M▪ 0.25M▪ 0.50M

3. How many moles of HCl are required to neutralize an aqueous solution of 2.0 mol Ca(OH)2?▪ 0.5 mol▪ 1.0 mol▪ 2.0 mol▪ 4.0 mol

4. In which of the following neutralization titrations of 1-molar solutions of H2SO4 and NaOH will the equivalence point be reached at the very end of the additions?

H2SO4(aq) + 2NaOH(aq) Na2SO4(aq) + 2H2O(aq)

▪ 200 mL of H2SO4 is slowly added to 100 mL of NaOH




The chemical processes inside a living cell are very sensitive to pH. Human blood is normally maintained at a pH very close to 7.4. You will learn about chemical processes that ensure that the pH of blood is kept near 7.4.

19.5

Salt Hydrolysis When is the solution of a salt acidic or

basic?

19.5

In general, salts that produce acidic solutions contain positive ions that release protons to water. Salts that produce basic solutions contain negative ions that attract protons from water.

19.5

▪ In salt hydrolysis, the cations or anions of a dissociated salt remove hydrogen ions from or donate hydrogen ions to water.

19.5

▪ To determine whether a salt solution is acidic or basic, remember the following rules:

19.5

▪ Vapors of the strong acid HCl(aq) and the weak base NH3(aq) combine to form the acidic white salt ammonium chloride (NH4Cl).

19.5

NH4Cl pH 5.3

NaCl pH 7

CH3COONa pH 5.3

▪ Universal indicator solution has been added to each of these 0.10M aqueous salt solutions.

19.5

Buffers What are the components of a buffer?

19.5

▪ A buffer is a solution of a weak acid and one of its salts, or a solution of a weak base and one of its salts.

The pH of a buffer remains relatively constant when small amounts of acid or base are added.

The buffer capacity is the amount of acid or base that can be added to a buffer solution before a significant change in pH occurs.

19.5

▪ Buffer of Ethanoic Acid and Sodium Ethanoate▪ Adding H+ produces additional ethanoic acid.▪ Adding OH- produces additional ethanoate ions.▪ The pH changes very little.

19.5

Animation 26 Discover the chemistry behind buffer

action.

1. Which of the following reactions would most likely yield a basic salt solution?▪ strong acid + weak base▪ weak acid + weak base▪ strong acid + strong base▪ weak acid + strong base

2. Choose the correct words for the spaces. A buffer can be a solution of a _________ and its _________.▪ weak acid, salt▪ strong acid, salt▪ weak acid, conjugate base▪ weak base, conjugate acid

3. Which of the following equations represents the reaction when a high pH substance is added to a dihydrogen phosphate ion-hydrogen phosphate ion buffer system?▪ H2PO4¯ + OH¯ HPO4

2¯ + H2O

▪ HPO42¯ + OH¯ PO4

3¯ + H2O

▪ H2PO4¯ + H+ H3PO4

▪ HPO42¯ + H+ H2PO4¯

Concept Map 19 Create your Concept Map using the

computer.

SC6. Students will understand the effects of motion on atoms and molecules in chemical and physical processes.

a) Compare and contrast atomic/molecular motion in solids, liquids, gases, and plasmas.

b) Collect data and calculate the amount of heat given off or taken in by chemical or physical processes.

c) Analyze (both conceptually and quantitatively) the flow of energy during change of state (phase).

SC2.Students will relate how the Law of Conservation of Matter is used to determine chemical composition in compounds and chemical reactions.

f) Explain the role of equilibrium in chemical reactions.

SC6.Students will understand the effects of motion on atoms and molecules in chemical and physical processes.

b) Collect data and calculate the amount of heat given off or taken in by chemical or physical processes.

SC5.Students will understand that the rate at which a chemical reaction occurs can be affected by changing concentration, temperature, or pressure and the addition of a catalyst.

a) Demonstrate the effects of changing concentration, temperature, and pressure on chemical reactions.

b) Investigate the effects of a catalyst on chemical reactions and apply it to everyday examples.

c) Explain the role of activation energy and degree of randomness in chemical reactions.

chemistry unit 4 ppt

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