Chem 2 Final

Consider the following reaction in aqueous solution:5Br-(aq) + BrO3-(aq) + 6H+(aq) →3Br2(aq) + 3H2O(l) If the rate of appearance of Br2(aq) at a particular moment during the reaction is 5.5x10-5M/s, what is the rate of disappearance of Br-(aq) at that moment? A) -9.2x10-5M/s B) -3.3x10‑ M/s C) -5.5x10-5M/s D) +3.3x10-5M/s

-9.2x10-5M/s

Which of the following solutions when mixed together in equal volumes will not form a buffer? A) 1 M HF and 0.5 M NaOH B) 1 M NaOOCCH3 and 1 M HOOCCH3 C) 1 M NH3and 1 M HCl D) 1 M NH4Cl and 1 M NH3

1 M NH3and 1 M HCl

What is the base ionization-constant for F- if the acid-ionization constant for HF is 1 x 10-4 ? A) 1 x 10-10 B) 1 x 10-5 C) 5 x 10-9 D) 1 x 10-12

1 x 10-10

What is the percent acid strength of HNO3, which has an initial concentration of 0.25 M and a pH of 2.60? A) 1.0 % B) 2.6 % C) 6.5% D) 10.4%

1.0%

Which of the following reactions has a negative entropy value? A) 2 Na(s) + Cl2(g) ⟶ NaCl(s) B) H2O(l) ⟶H2O(g) C) NH4Cl(s) ⟶NH4Cl(aq) D) C6H6(l) + 15/2 O2(g) ⟶6CO2(g) + 3H2O(g)

2 Na(s) + Cl2(g) ⟶ NaCl(s)

The glass for making pH electrodes is sensitive to the number of molecules of specific heavy metal oxides dispersed throughout the silicone dioxide matrix. lithium oxide (MW = 30) is present in some pH glasses at a concentration of 20 M. How many grams of lithium oxide are present in 100 g of pH glass (density of pH glass = 2.5 g/cm3). A) 24 g B) 5.5 g C) 45 g D) 15 g

24 g

Calculate the mass percent of a saturated solution of KBr at 10oC if its solubility is 60 g/100 g H2O at 10oC. A) 37.5% B) 0.375% C) 60% D) 33%

37.5%

The solubility of magnesium chloride (MW = 95.2) at the freezing point of water is about 53 g in 100 mL of water. What is the molality of this solution? (Assume density of water is 1.00 g/mL.) A) 5.57 m B) 0.557 m C) 5.30 m D) 0.53 m

5.57 m

A saturated solution of NaBr has a concentration of 45% NaBr in water. What is its solubility in water? A) 82 g / 100 g H2O B) 4.5 g / 100 g H2O C) 55 g / 100 g H2O D) 45 g / 100 g H2O

82 g / 100 g H2O

What is the difference between a battery and a fuel cell? A) A battery contains a set amount of redox material and a fuel cell is continuously fed a supply of redox material. B) A battery is small, and a fuel cell is large. C) Batteries can be hooked up in series to produce higher voltages and fuel cells cannot. D) A fuel cell is capable of producing a higher voltage than a battery.

A battery contains a set amount of redox material and a fuel cell is continuously fed a supply of redox material.

What is the definition of a Bronsted-Lowry base? A) A compound that donates a proton. B) A compound that accepts a proton. C) A compound that donates a hydroxide ion. D) A compound that accepts a hydroxide ion.

A compound that accepts a proton.

What is the definition of a Bronsted-Lowry acid? A) A compound that donates a proton. B) A compound that accepts a proton. C) A compound that donates a hydroxide ion. D) A compound that accepts a hydroxide ion.

A compound that donates a proton.

What is an amphoteric series

A species that has the potential to act both as an acid and as a base according to Brønsted-Lowry Theory is said to be amphoteric. ... Since water has the potential to act both as an acid and as a base, water is amphoteric.

Describe the difference between a spontaneous and non-spontaneous process.

A spontaneous process can occur with no energy while a non-spontaneous process requires energy.

What is the Arrhenius definition of an acid?

A substance that increases H3O+ concentration when it is dissolved in water. (gives off H+)

What is the Arrhenius definition of a base?

A substance that increases OH- concentration when it is dissolved in water. (gives off OH-)

What is Henry's Law?

According to this law, gases dissolve in liquids in proportion to the partial pressures, depending also on their solubilities in the specific fluids and on the temperature. C = kP concentration of a dissolved gas k = Henry's law constant partial pressure of the gas

Which of the following will not change the equilibrium concentrations in the following reaction at the bottom of a lake open to the atmosphere? CaCO3(s) + H2O(l) ←→HCO3-(aq) + Ca2+(aq) + OH-(aq) Keq = 2 x 10-3 A) Adding a little more water to the lake. B) The temperature of the lake changes due to global warming. C) The carbon dioxide concentration in air increases due to burning fossil fuels. D) Acid rain lowers the pH of the lake.

Adding a little more water to the lake.

Which of the following will not change the equilibrium concentrations in the following reaction at the bottom of a lake open to the atmosphere? CaCO3(s) + H2O(l) ←→HCO3-(aq) + Ca2+(aq) + OH-(aq) Keq = 2 x 10-3 A) Adding solid CaCO3 to the lake. B) The temperature of the lake changes due to global warming. C) The carbon dioxide concentration in air increases due to burning fossil fuels. D) Acid rain lowers the pH of the lake.

Adding solid CaCO3 to the lake.

In the following redox reaction, which element is undergoing oxidation? Al + Cr2O72-+ 28H+ →Al3++ 2Cr3++ 14H2O A) Al B) H C) O D) Cr

Al

Which of the following factors affect the rate of a chemical reaction. Mark all factors that apply. A) temperature of the reaction B) chemical nature of the reactants C) concentration of the reactants D) presence of a catalyst

All of them

Which of the following define of a buffer? Check all that apply. A) A solution that resist change in pH upon addition of an acid or a base. B) A solution made up of a weak acid and its conjugate base. C) A solution made up of a weak base and its conjugate acid. D) A 1 M solution of ammonium acetate is a buffer solution.

All of them.

Which of the following species would be considered amphoteric? Check all that apply. A) H2PO4- B) S2− C) CO32− D) HSO4−

All of them.

Explain the difference between a weak acid and a strong acid. Give an example of each.

An acid is a strong acid if it fully dissociates into its component ions in solution, whereas an acid is a weak acid if it does not fully dissociate into its component ions in solution. For example, HCl is a strong acid that fully dissociates into H+ and Cl- ions. On the other hand, CH3COOH is a weak acid that partially dissociates into CH3COO- and H+. However, weak acids can fully dissociate if reacted with a sufficiently strong base.

What is an alloy? Give an example of an alloy.

An alloy is a mixture or metallic-solid solution composed of two or more elements. Examples of alloys include materials such as brass, pewter, phosphor bronze, amalgam, and steel.

Which of the following is (are) spontaneous processes? Check all that apply. A) Life B) Fresh perked coffee cooling down. C) Lipstick melting on a hot day. D) The air inside your refrigerator cooling on a hot summer day.

B,C,D

Which of the following is not a strong acid? A) CH3CO2H B) HCl C) HNO3 D) H2SO4

CH3CO2H

Which of the following gases would be least soluble in water? A) CH4 B) NH3 C) CH3Cl D) SO2

CH4

Which reaction has a positive entropy value? A) CaCO(s)⟶CaO(s) + CO2(g) B) Ag+(aq) + Cl−(aq)⟶AgCl(s) C) NH3(g) ⟶NH3(l) D) 2Fe(s) + 3O2(g) ⟶Fe2O3(s)

CaCO(s)⟶CaO(s) + CO2(g)

Which of the following will not have an effect on a system at equilibrium? A) Changing the amount of a solid product. B) Changing the temperature of the system. C) Changing the concentration of one of the reactants. D) Changing the concentration of one of the products.

Changing the amount of a solid product.

What makes colligative properties different from other solution properties such as density and viscosity? A) Colligative properties only depend on the number of particles present and not their identity. B) Colligative properties only apply to solutions of ions. C) Colligative properties can only be applied to binary mixtures. D) Colligative properties are not affect by the pH of a solution.

Colligative properties only depend on the number of particles present and not their identity.

Which of the following slightly soluble compounds has a solubility greater than that calculated from its solubility product because of hydrolysis of the anion present? A) AgCl B) PbSO4 C) CuI2 D) MgCO3

CuI2

What is the most influential intermolecular force that allows a little bit of hexane to dissolve in water? A) Dispersion forces B) Dipole-dipole interactions C) Hydrogen bonding D) Ion-dipole interactions

Dispersion forces

How do enzymes catalyze reactions

Enzymes catalyze reactions by lowering the activation energy necessary for a reaction to occur. The molecule that an enzyme acts on is called the substrate. In an enzyme-mediated reaction, substrate molecules are changed, and product is formed.

Which of the following statements is true about how enzymes catalyze reactions? A) Enzymes speed up biochemical reactions by increasing the activation energy of the reaction. B) Enzymes speed up biochemical reactions by lowering the activation energy of the reaction. C) Enzymes speed up biochemical reactions by increasing the temperature of the reaction. D) Enzymes speed up biochemical reactions by lowering the temperature of the reaction.

Enzymes speed up biochemical reactions by lowering the activation energy of the reaction.

Explain why an equilibrium between Br2(l) and Br2(g) would not be established if the container were not a closed vessel shown in Figure 13.5.

Equilibrium cannot be established between the liquid and the gas phase if the top is removed from the bottle because the system is not closed; one of the components of the equilibrium, the Br2 vapor, would escape from the bottle until all liquid disappeared. Thus, more liquid would evaporate than can condense back from the gas phase to the liquid phase.

What best explains why ethanol, CH3CH2OH, is miscible in water, whereas ethanethiol, CH3CH2SH, is only soluble to the extent of 1.5 grams per 100 mL in water? A) Ethanol can hydrogen bond with water, whereas ethanethiol cannot. B) Ethanethiol has a higher molecular weight than ethanol. C) Ethanethiol hydrogen bonds with itself excluding water molecules, whereas ethanol hydrogen bonds with water only. D) Ethanol has a higher mass percentage of hydrogen atoms than ethanethiol, thus making it more likely to hydrogen bond with

Ethanol can hydrogen bond with water, whereas ethanethiol cannot.

Definition of Second Law of Thermodynamics

Every energy transfer or transformation increases the entropy of the universe. when energy is changed from one form to another, some useful energy is always degraded into lower quality energy (usually heat)

The fact that the process of forming a solution formation is spontaneous means that it gives off heat. True or False

False

The second law of thermodynamics states that in order for a reaction to occur it must have positive standard entropy True or False

False

The standard entropy of a substance does not rely on the temperature of the substance. True or False

False

What reactions result in an increase or decrease in entropy

For a given substance, the entropy of the liquid state is greater than the entropy of the solid state. Likewise, the entropy of the gas is greater than the entropy of the liquid. Therefore, entropy increases in processes in which solid or liquid reactants form gaseous products. Entropy also increases when solid reactants form liquid products. Entropy increases when a substance is broken up into multiple parts. The process of dissolving increases entropy because the solute particles become separated from one another when a solution is formed. Entropy increases as temperature increases. An increase in temperature means that the particles of the substance have greater kinetic energy. The faster moving particles have more disorder than particles that are moving more slowly at a lower temperature. Entropy generally increases in reactions in which the total number of product molecules is greater than the total number of reactant molecules. An exceptions to this rule is when a gas is being produced from nongaseous reactants. The entropy is decreasing because a gas is becoming a liquid. The entropy is decreasing because four total reactant molecules are forming two total product molecules (gas). The entropy is decreasing because a solid is formed from aqueous reactants.

f you observe the following reaction at equilibrium, is it possible to tell whether the reaction started with pure NO2 or with pure N2O4? NO2 = N2O4

For the reaction , when equilibrium is achieved, the following relationship will be satisfied: . Thus, at equilibrium, both reactants and products will be present. Because the same position of equilibrium will be achieved, no matter from which direction (either combination of NO2 or decomposition of N2O4), it is not possible to tell in which direction the reaction took place to achieve the equilibrium position. Prior to achieving equilibrium, it is possible to tell in which direction the reaction is proceeding. For example, in this system, if the color of the reaction mixture were a deep reddish brown that became a lighter intensity with time, then it would be possible to recognize that equilibrium is being approached as a result of the brown NO2 molecules combining to form the colorless N2O4 molecules.

Identify the conjugate acid in the following reaction. H2PO4−+ HCl ⟶H3PO4+ Cl− A) H3PO4 B) Cl− C) HCl D) H2PO4−

H3PO4

Heat is released when some solutions form; heat is absorbed when other solutions form. Provide a molecular explanation for the difference between these two types of spontaneous processes.

Heat released: breaking bond Heat absorbed: creating bond Heat is released when the total intermolecular forces (IMFs) between the solute and solvent molecules are stronger than the total IMFs in the pure solute and in the pure solvent: Breaking weaker IMFs and forming stronger IMFs releases heat. Heat is absorbed when the total IMFs in the solution are weaker than the total of those in the pure solute and in the pure solvent: Breaking stronger IMFs and forming weaker IMFs absorbs heat.

Which of the following properties is not a colligative property? A) Henry's law of proportional gas pressure and solubility B) Freezing point depression proportional to the number of particles in solution C) Boiling point elevation proportional to the number of particles in solution D) Raoult's Law of vapor pressure lowering proportional to the mole ratio

Henry's law of proportional gas pressure and solubility

How does an increase in temperature affect rate of reaction? Explain this effect in terms of the collision theory of the reaction rate.

It increases the rate of reaction by increasing the average kinetic energy of the molecules involved. This results in a larger fraction of collisions producing activated complexes.

What is the purpose of the salt bridge in a voltaic cell? A) It maintains charge balance between the anode and cathode compartments. B) It provides cations for reduction. C) It stores anions for oxidation. D) It catalyzes the reaction.

It maintains charge balance between the anode and cathode compartments.

METB is one of the compounds used as octane enhancers in unleaded gasoline. It is manufactured by the catalytic conversion of acetylene to benzene: 3C2H2(g) → C6H6(g). Which value of Kc would make this reaction most useful commercially? A) Kc = 0.001 B) Kc = 1.00 C) Kc = 100

Kc = 100

For a titration to be effective, the reaction must be rapid and the yield of the reaction must essentially be 100%. Is Kc > 1, < 1, or ≈ 1 for a titration reaction?

Kc> 1; the product must be formed in overwhelmingly large proportions.

What is not an advantage of Li ion batteries as compared to other conventional batteries? A) Li ion batteries are inexpensive. B) Li ion batteries are light. C) Li ion batteries do not lose their charge in storage. D) Li ion batteries provide a high constant voltage per cell.

Li ion batteries are inexpensive.

What is meant by the half reaction method? A) Oxidation and reduction in electrochemical reactions are split into two separate reactions. B) One half of a reaction concerns only reactants and the other half of the reaction only concerns products. C) The point at which half of the reaction is complete. It is analogous to half-life for electrochemical reactions. D) It is the potential of an oxidation or reduction when all the reactants are at one molar concentration and standard temperature and pressure.

Oxidation and reduction in electrochemical reactions are split into two separate reactions.

Which of the following is not a relationship between thermodynamic quantities of state? A) ΔGo= −RT ln K B) Eocell= RTnF ln K C) ΔGo= −nFEocell D) Q = nF

Q = nF

Which of the following gases would be most soluble in water? CH4 O2 CO2 SO2

SO2

Which of the following would not be considered an amphoteric species? A) SO42- B) H2O C) HCO3- D) HSO3-

SO42-

Give definitions for unsaturation, saturation and supersaturation.

Supersaturation is where the amount of solute necessary to reach saturation (where no more solute can be added), is surpassed. This can be done by heating up the solution and mixing in more of the solute. Saturation is when the solute has dissolved and taken in as much solute it can take to be at equilibrium. If you try to add more solute to the solute, the rest will remain in its state. For example, when you mix sugar and water, you can add just enough sugar to the volume of water until it reaches saturation. If you add additional sugar, it remains as a solid and sits at the bottom of the container. Unsaturated means there is not enough solute dissolved in the solvent to reach equilibrium. Going along with the sugar example, its hard to say but if you add just a quarter of a teaspoon to a gallon of water, the solution is unsaturated and is nowhere even close to being saturated. In this case, you could more sugar until right before the saturated point of the solution.

Identify the Bronsted-Lowry acid, its conjugate base, the Bronsted-Lowry base and its conjugate acid in the following reaction. H2PO4−+ HCl ⟶H3PO4+ Cl−

The Bronsted-Lowry acid is HCl and its conjugate base is Cl- because it donates a proton. The Bronsted-Lowry base is H2PO4- and its conjugate acid is H3PO4 because it accepts a proton.

Definition of Gibbs Free energy

The amount of "free" or "useful" energy available to do work. It combines enthalpy and entropy into a single value.

When writing an equation, how is a reversible reaction distinguished from a nonreversible reaction? A) The equation displays a double arrow between reactants and products. B) The equation displays an arrow to the right towards products. C) The equation displays an arrow to the left towards reactants. D) The letters "EQ" are displayed above the arrows in the equation.

The equation displays a double arrow between reactants and products.

Which of the following statements does not affect the rate of reactions according to Collision Theory. A) The number of collisions between reactants per unit time. B) The orientation of reactants when they collide. C) The magnitude of the activation energy required to attain the transition state between the reacting molecules or atoms. D) The frequency of collisions between the reactants and the products.

The frequency of collisions between the reactants and the products.

Account for the increase in reaction rate brought about by a catalyst.

The general mode of action for a catalyst is to provide a mechanism by which the reactants can unite more readily by taking a path with a lower reaction energy. The rates of both the forward and the reverse reactions are increased, leading to a faster achievement of equilibrium.

Consider the following reaction: CO(g) + NO2(g) → CO2(g) + NO(g) If the rate law for this reaction is: rate = k [NO2], what is the effect on the rate if the starting pressure of NO2is increased from 0.25 atm to 1.0 atm? A) The rate will increase by 4-fold. B) The rate will decrease by 4-fold. C) The rate will increase by 16-fold. D) The rate will not change.

The rate will increase by 4-fold.

Consider the following reaction: CO(g) + NO2(g) → CO2(g) + NO(g) If the rate law for this reaction is: rate = k [NO2], what is the effect on the rate if the starting pressure of CO is increased from 0.25 atm to 1.0 atm? A) The rate will increase by 4-fold. B) The rate will decrease by 4-fold. C) The rate will increase by 16-fold. D) The rate will not change.

The rate will not change.

Chemical reactions occur when reactants collide. What are two factors that may prevent a collision from producing a chemical reaction?

The reactants either may be moving too slowly to have enough kinetic energy to exceed the activation energy for the reaction, or the orientation of the molecules when they collide may prevent the reaction from occurring.

Supersaturated solutions of most solids in water are prepared by cooling saturated solutions. Supersaturated solutions of most gases in water are prepared by heating saturated solutions. Explain the reasons for the difference in the two procedures.

The solubility of solids usually decreases upon cooling a solution, while the solubility of gases usually decreases upon heating.

Definition of a buffer

They are weak acid-base pairs. They maintain proper cellular pH. a solution that resists changes in pH when acid or alkali is added to it. Buffers typically involve a weak acid or alkali together with one of its salts.

Why has it become accustomed to put vinegar on your fish and chips? A) To create salts out of the volatile, basic amines given off by dead fish. B) To neutralize the lemon mixed in with the batter. C) To prevent oxidation of the fish. D) To promote the growth of beneficial bacteria.

To create salts out of the volatile, basic amines given off by dead fish.

Adding sodium cyanide to a saturated solution of AgCl(s) containing suspended AgCl will result in dissolving more AgCl since CN- forms a soluble complex with silver. True or False

True

In the discussion topic of this module, the terms thermodynamic entropy and information entropy were explained. It can be said that the main difference between the two terms has to do with thermodynamic entropy having to do with microstates and probability and information entropy has to do with objects. True or False

True

Lewis acid-base adducts (products) can be charged complexes or uncharged solids. True or False

True

The conjugate base of a strong acid has a weaker conjugate base than water since the hydrogen ion reacts with water to form the hydronium ion. True or False

True

The entropy of a system will increase when it is heated. True or False

True

The fact that the process of forming a solution is exothermic means that it gives off heat. True or False

True

The stronger the acid strength of an acid the weaker its conjugate base. True or False

True

Explain what it means when water autoionizes? Show the equilibrium reaction, equilibrium expression and ion-product constant for water, Kw.

Water autoionization refers to when water reacts with itself to dissociate into its ionic forms H3O+ and OH-. Equilibrium expression (using ion-product constant): Ka = Kw = [H3O+][OH-] Equilibrium reaction: please see exam work calculations

If a reaction is reversible, when can it be said to have reached equilibrium?

When a system has reached equilibrium, no further changes in the reactant and product concentrations occur; the reactions continue to occur, but at equivalent rates.

When does changing the pressure on a system by lowering the volume always affect the equilibrium of a reaction? A) When the pressure of reactant gas is different from the pressure of product gas. B) When the reaction stoichiometry has unequal moles of reactant gas and product gas. C) When the grams of reactant gas are different from the grams of product gas. D) When the moles of reactant gas are different from the moles of product gas.

When the reaction stoichiometry has unequal moles of reactant gas and product gas.

You observe the following reaction at equilibrium. N2(g) + O2(g) ←→2NO(g) Explain why you cannot tell whether the reaction started with pure N2and O2gas or pure NO gas.

You cannot tell whether the reaction started with pure N2 or O2 because at equilibrium, there are an equal amount of reactants and products. If the reaction was observed anywhere before the reaction reached equilibrium, an individual would be able to distinguish which one is the reactant. One example of can determine this by the larger volume before equilibrium, the color change before equilibrium etc. Color change was one we have used in titration labs because after we dye our reactant, it is easy to record the color change when it reaches equilibrium. When a reaction reaches equilibrium, it changes colors (in our lab it changed from pale orange to a pale amber color).

How do you typically prepare a supersaturated solution of a salt in water?

You would prepare a supersaturated solution of a salt in water by heating up the water and dissolving as much salt (NaCl, if using table salt) into the water until no more salt can dissolve into the water at that temperature. Excess salt will crystalize out of solution. This process can be done by heating and dissolving in steps, or all at once.

Assuming that no equilibria other than dissolution is involved, calculate the concentration of iodide ions, [I-(aq)], in the following saturated solution of lead iodide, PbI2(s). Solubility product PbI2 Ksp = 9.8 x 10-9 A) [I-] = 0.0043M B) [I-] = 9.8 x 10-9M C) [I-] = 0.0013M D) [I-] = 0.0026M

[I-] = 0.0026M

Definition of Entropy

a measure of the randomness or disorder of a system

What is a Bronsted-Lowry base?

a molecule or ion that is a proton acceptor

What is a Bronsted-Lowry acid?

a molecule or ion that is a proton donor

When KNO3 is dissolved in water, the resulting solution is significantly colder than the water was originally. A) Is the dissolution of KNO3 an endothermic or an exothermic process? B) What conclusions can you draw about the intermolecular attractions involved in the process? C) Is the resulting solution an ideal solution?

a) The dissolution is endothermic because KNO3 requires energy from the water to break the bond (The process is endothermic as the solution is consuming heat). b) Attraction between the K+ and NO3- ions is stronger than between the ions in water ( the ions interactions have a lower, more negative energy). Therefore, the dissolution process increases the energy of the molecular interactions, it consumes the thermal energy of the solution to make up for the difference. c) No, an ideal solution is formed with no appreciable heat release or consumption

According to LeChatelier's Principle which of the following will not affect the equilibrium of the following reaction in a closed container? Check all correct answers that apply. Heat + 2NH3(g)←→3H2(g) + N2(g) ΔH = +1200 kJ A) heat the container B) cool the container C) increase the pressure within the closed container by reducing the volume D) add argon gas to increase the pressure within the closed container

add argon gas to increase the pressure within the closed container

What is the compound kryolite used for in the electrolysis of aluminum? A) as a solvent and electrolyte B) as the feedstock for aluminum C) as the anode D) as a byproduct

as a solvent and electrolyte

Which of the following actions will increase the amount of SO3 gas produced (shift the reaction to the right) in a closed container in the following reaction? Check all correct answers that apply. 2SO2(g) + O2(g)←→2SO3(g) + heat A) decrease the temperature of the reaction B) increase the temperature of the reaction C) remove SO3 from the reaction D) increase the pressure of the reaction by decreasing the volume of the closed container

increase the temperature of the reaction increase the pressure of the reaction by decreasing the volume of the closed container

What governs Solubility?

intermolecular forces between solute and solvent The solubility of one substance in another is determined by the balance of intermolecular forces between the solvent and solute, and the entropy change that accompanies the solvation. Factors such as temperature and pressure will alter this balance, thus changing the solubility.

Predict whether each of the following substances would be more soluble in water (polar solvent) or in a hydrocarbon such as heptane (C7H16, nonpolar solvent): (a) vegetable oil (nonpolar) (b) isopropyl alcohol (polar) (c) potassium bromide (ionic)

like dissolves like a) heptane (nonpolar) b) water (polar) c) water (polar, ionic can be polar)

Which of the following actions will decrease the amount of hydrazine gas (N2H4) produced in a closed container in the following reaction? Check all correct answers that apply. N2(g) + 2H2(g) ←→N2H4(g) + heat ΔH = 95 kJ A) decrease the temperature of the reaction B) increase the temperature of the reaction C) remove N2 from the reaction D) increase the pressure of the reaction by decreasing the volume of the closed container

remove N2 from the reaction increase the pressure of the reaction by decreasing the volume of the closed container

When equal moles of a strong acid and a weak base are mixed the resulting solution is: A) slightly acidic B) slight basic C) neutral D) Unable to be determined depending the relative strengths of the acid and base.

slightly acidic

In terms of collision theory, to which of the following is the rate of a chemical reaction proportional? (a) the change in free energy per second (b) the change in temperature per second (c) the number of collisions per second (d) the number of product molecules

the number of collisions per second

Consider the following reaction in aqueous solution: CaCO3(s) + H2SO4(aq) →CaSO3(aq) + CO2(g) + H2O(l) Which of the following factors will least likely have an effect on the rate of this reaction if it is considered first order with respect to the two reactants? A) the temperature of the reaction B) the amount of dispersion of CaCO3(s) C) the molarity of the H2SO4(aq) D) the partial pressure of the CO2(g)

the partial pressure of the CO2(g)