Chem

Which of the following is a decomposition reaction?

2H2O2 → 2H2O + O2

Which species would be considered a spectator ion based on the following equation? Ba2+ + 2NO3‐ + 2Na+ + SO42+ → BaSO4(s) + 2NO3‐ + 2Na+

2NO3^‐

Propane, C3H8, burns to produce carbon dioxide and water by the equation below. What is the coefficient in front of the carbon dioxide in the balanced equation? C3H8 +O2 → CO2 +H2O a) 1 b) 2 c) 3 d) 6

3

e Haber Process is a method for the production of ammonia, an important chemical intermediate. The reaction for this process is: N2 + 3H2 → 2NH3. When the equation is correctly interpreted in terms of moles, how many moles of H2 will react with one mole of N2? a) 1 b) 2 c) 3 d) 6

3

Which set of coefficients balances the equation? _____ CH4 → _____C3H8 + ______H2 a) 3,1,1 b) 3,2,1 c) 3,1,2 d) 6,2,2

3,1,2

Refer to Haber Process. According to the mole interpretation, how many grams of NH3 could be produced by the complete reaction of 2.80 grams of N2 and excess H2? a) 34.0 b) 17.0 c) 3.10 d) 3.40

3.40

In the reaction 2H2O → 2H2 + O2, 2.0 mol water will produce how many grams of O2? a) 16 b) 32 c) 36 d) 64

32

Suppose 2.43 g of magnesium is reacted with 3.20 g of oxygen: 2Mg + O2 → 2MgO. How many grams of MgO will be produced? a) 5.63 b) 1.27 c) 8.06 d) 4.03

4.03

Given the equation 2CO + O2→2CO2, how many grams of CO2 form if 34.0 grams of CO are combined with excess oxygen? a) 53.4 b) 21.6 c) 145 d) 107

53.4

In the reaction 2CH4 + O2 → 2CO + 4H2, how many molecules of CO will be produced by the complete reaction of 1.60 grams of CH4? a) 12.0x10^23 b) 3.01x10^22 c) 6.02x10^22 d) 2.00

6.02x10^22

The following questions are based on the following reaction. 4HCl + MnO2 → Cl2 + 2H2O + MnCl2 What substance is oxidized? a) Cl in HCl b) Mn in MnO2 c) H in HCl d) O in MnO2

Cl in HCl

Which ions in the following reaction would be classified as spectator ions? Zn+2H+ +2Cl‐ →Zn2+ +2Cl‐ +H2 a) Zn^2+ b) H+ c) Cl- d) more than one response is correct

Cl‐

two or more substances react to form a single substance. Combination reactions may be either redox or nonredox reactions. The general form of the equation for a combination reaction is: A + B → C

Combination Reactions

Which of the following is a single replacement reaction?

CuO+H2 →Cu+H2O

one substance is broken down into two or more simpler substances. Decomposition reactions may be either redox or nonredox reactions. The general form of the equation for a decomposition reaction is: A → B + C.

Decomposition Reaction

Which of the following contains the metal with the highest oxidation number? a) CaCl2 b) NaCl c) FeCl3 d) CuCl2

FeCl3

Which of the following is a double replacement reaction?

HBr+KOH→H2O+KBr

The following questions are based on the following reaction. 4HCl + MnO2 → Cl2 + 2H2O + MnCl2 What is the reducing agent? a) HCl b) Cl2 c) MnO2 d) MnCl2

HCl

-Many reactions take place between compounds or elements that are dissolved in water. Ionic compounds and some polar covalent compounds break apart (dissociate) when they dissolve in water and form ions -The equations for reactions that occur between dissolved materials can be written in three ways called molecular equations, total ionic equations and net ionic equations.

IONIC EQUATIONS - a subset of Double Replacement

Considerthereactantsandproposetherightsideoftheequation. Mg + H2SO4 → __________

MgSO4 + H2

The following questions are based on the following reaction. 4HCl + MnO2 → Cl2 + 2H2O + MnCl2 What substance is reduced? a) Cl in HCl b) Mn in MnO2 c) H in HCl d) O in MnO2

Mn in MnO2

The following questions are based on the following reaction. 4HCl + MnO2 → Cl2 + 2H2O + MnCl2 What is the oxidizing agent? a) HCl b) Cl2 c) MnO2 d) MnCl2

MnO2

-Rule 1: The Oxidation Number of any uncombined element is 0. For example: Fe (0), Cl2 (0), and Ca (0) -Rule 2: Oxidation Number of simple ion is equal to charge on the ion. For example: Mg2+(+2), O2-(-2) -Rule 3:The O.N. of group IA and IIA elements when they are in compounds are always +1 and +2, For example: Na2S (Na = +1) and Ca(NO3)2 (Ca = +2) -Rule 4:The Oxidation Number of hydrogen is always +1.  -Rule 5:The O.N. of oxygen is -2 except in peroxides where it is -1. For example: MgO (O = -2), H2O2 (O = -1) -Rule 6:The algebraic sum of the oxidation numbers of all atoms in a complete compound equals zero. For example:MgSO4 (O.N. of Mg = +2 by rule 2, O.N. of O = -2 by rule 5, and O.N. of S = +6 by algebra and rule 6)  -Rule 7:The algebraic sum of the O.N. of all the atoms in a polyatomic ion is equal to the charge on the ion. For example: HCO3- (O.N. of H is +1 by rule 4, O.N. of O is -2 by rule 5, and O.N. of C is +4 by algebra and rule 7)

Oxidation number rules

(also called oxidation states) are positive or negative numbers assigned to elements in chemical formulas according to a set of rules. Term oxidation number is like the charge on an ion but includes covalent atoms

Oxidation numbers

In a redox reaction, the substance that contains an element that is oxidized during the reaction is called the *reducing agent.*(loses e-'s, o.n ^, becomes oxidized) In a redox reaction, the substance that contains an element that is reduced during the reaction is called the *oxidizing agent.*(gains e-'s, o.n decrease, becomes reduced)

Oxidizing and reducing agents

The products in a chemical equation are the substances written on the right side of the arrow. When two or more products are involved in an equation, they are separated by a plus sign (+). 2H2 (g) + O2 (g) → 2H2O (l) Products

Products of a chemical reaction

The reactants in a chemical equation are the substances written on the left side of the arrow that points toward the products. When two or more reactants are involved in an equation, they are separated by a plus sign (+). Reactants 2H2 (g) + O2 (g) → 2H2O (l)

Reactants of a chemical Reaction

Which of the following is a combination reaction?

SO2 +O2 →2SO3

always redox reactions because they occur when one element reacts with a compound, displaces one of the elements from the compound, and becomes part of a new compound. The general form of the equation for a single replacement reaction is: A + BX → B + AX

Single replacement reaction

A percentage yield greater than 100% has been reported in a scientific paper you are assigned to read. What would be a reasonable explanation for this?

Small measurement errors could have caused this to occur.

Consider the reactants in the partial equation given. Which choice is a product? H3PO4 + Sr(OH)2 → __________

Sr3(PO4)2

Redox group Redox combination: A + B AB Redox single replacement: A + BC AC + B Redox decomposition: AB A + B Non-Redox group Combination: AB + CD ABCD Double replacement: AB + CD AD + CB Decomposition: ABCD AB + CD

Summary of six reaction types

In which of the following does an element have an oxidation number of +4? a) TiO2 b) HBr c) SO3 d) SO4 ^2-

TiO2

Which of the following statements is true about the reaction? 2CH4 +3O2 →2CO2+4H2O

Water and carbon dioxide are products

Which of the following reactions is correctly balanced?

Zn+2HCl→H2 +ZnCl2

Barium sulfate is often ingested to aid in the diagnosis of GI tract disorders. What type of equation is this?

a net ionic equation

Tincture of iodine is an antiseptic. What is a tincture?

a substance dissolved in alcohol

Convert a temperature of 210 K into Celsius degrees. a. -63.0°C b. 63.0°C c. 242°C d. 483°C

a. -63.0°C

A gas sample collected at 35.0°C and a pressure of 710 torr has a volume of 200mL. The temperature and pressure are changed and the gas is compressed to 150 mL. The new temperature is 40.0°C; what is the new pressure? a. 1.27 atm b. 1.08 x 10³ torr c. 541 torr d. 0.712 atm

a. 1.27 atm

2500 liters of oxygen gas is produced at 1.00 atm of pressure. It is to be compressed and stored in a 20.0 liter cylinder. If temperature is constant, calculate the pressure of the oxygen in the cylinder. a. 125 atm b. 4.0 atm c. 80.0 atm d. 8.00 atm

a. 125 atm

Near room temperature air has a density of 1.18 x 10⁻³ g/mL. What volume of 30.77 g of air occupy? a. 2.61 x 10⁴ mL b. 3.63 x 10⁻² mL c. 3.83 x 10⁻⁵ mL d. 3.08 x 10⁻¹ mL

a. 2.61 x 10⁴ mL

A 5.00 liter samples of gas measured at 27.0°C and 1.25 atm of pressure has a mass of 10.13 g. What is the molecular weigh of the gas in u? a. 39.9 b. 0.898 c. 2.57 d. 2.50 x 10⁻²

a. 39.9

Which of the following correctly arranges the given compounds in order of increasing boiling point (lowest to highest)? a. CH₃CH₂CH₂CH₃ < CH₃CH₂-OH < CH₃CH₂CH₂-OH b. CH₃CH₂CH₂CH₃ < CH₃CH₂CH₂-OH < CH₃CH₂-OH c. CH₃CH₂-OH < CH₃CH₂CH₂-OH < CH₃CH₂CH₂CH₃ d. CH₃CH₂-OH < CH₃CH₂CH₂CH₃ < CH₃CH₂CH₂-OH

a. CH₃CH₂CH₂CH₃ < CH₃CH₂-OH < CH₃CH₂CH₂-OH

Which of the following gases would diffuse about one-third as fast as helium gas, He? a. HCl b. NH₃ c. CH₄ d. H₂O

a. HCl

When a liquid sample is taken from sea level to a higher elevation, what happens to the external (atmospheric) pressure on the liquid and the boiling point of the liquid? a. both decrease b. both increase c. pressure goes down, bu boiling point goes up d. pressure goes up, but boiling point goes down

a. both decrease

A gas sample is collected in a balloon. What happens to the density of the gas sample as the sample is heated? a. decreases b. increases c. does not change d. could increase or decrease, depending on how much it was heated

a. decreases

A percentage yield less than 100% is often obtained in a reaction. Which of the following could be the reason(s) for obtaining less than theoretically predicted?

all of the above -side reactions occurred -poor laboratory technique -reaction did not go to completion

A pressure is recorded as 622 torr. What is the pressure in atm? a. 1.22 b. 0.818 c. 5.17 d. 0.0393

b. 0.818

A 3.2 liter sample of gas is at 40°C and 1.0 atmosphere of pressure. If the temperature decreases to 20°C and the pressure decreases to 0.60 atmospheres, what is the new volume in liters? a. 5.7 b. 5.0 c. 1.8 d. 0.20

b. 5.0

What pressure will 3.20 mol of N₂ gas exert if confined in a 15.0 L container at 100°C? a. 1.75 atm b. 6.53 atm c. 3.27 atm d. 13.0 atm

b. 6.53 atm

Calculate the kinetic energy of a 0.500 g particles traveling at 5.50 cm/s. a. 2.75 g cm²/s² b. 7.56 g cm²/s² c. 51.1 g cm²/s² d. 6.88 g cm²/s²

b. 7.56 g cm²/s²

Increasing the pressure on a gas at constant temperature does what to the volume of the gas? a. increases b. decreases c. has no effect d. increases up to a certain point

b. decreases

The temperature of a liquid is decreased. What happens to the vapor pressure of the liquid as a result? a. it increases b. it decreases c. it is not changed d. it increases or decreases depending on how large a temperature change occurs

b. it decreases

Cohesive forces in matter are related to a. potential energy from particle repulsions b. potential energy from particle attractions c. kinetic energy d. more than one response is correct

b. potential energy from particle attractions

The direct change from a solid state to the vapor state is called a. evaporation b. sublimation c. boiling d. fusion

b. sublimation

Using d= m/V, what is the volume (V) of a solid that has a density of 3.14 g/cm³ and has a mass of 7.04 grams? a. 22.1 cm³ b. 22.11 cm³ c. 2.24 cm³ d. 2.242 cm³

c. 2.24 cm³

The energy involved in chemical reactions:

can take many forms

A 5.00 liter gas sample is collected at a temperature and pressure of 27.0°C and 1.20 atm. It is desired to transfer the gas to a 3.00 liter container at a pressure of 1.00 atm. What must be the temperature of the gas in the 3.00 liter container? a. 216 K b. 417 K c. 13.5 °C d. 150 K

d. 150 K

What volume of ammonia gas, NH₃, in liters is produced at STP by the complete reaction of 100 g of nitrogen, N₂, with excess hydrogen? N₂ + 3H₂ → 2NH₃ a. 74.7 b. 747 c. 62.5 d. 160

d. 160

Given the following heat of fusion of ice = 80.0 cal/g; specific heat of ice = 0.480 cal/g; and specific heat of water = 1.00 cal/g. Calculate the amount of heat required to melt 30.0 g of ice at 0°C. a. 14.4 cal b. 2.41 cal c. 80.0 cal d. 2.40 kcal

d. 2.40 kcal

A mixture of helium, argon and krypton is made and stored in a cylinder at a total pressure of 2.80 atm. The partial pressure of helium is 900 torr, and that of argon is 250 torr. What is the partial pressure of krypton in the mixture? a. 1.18 atm b. 1.51 atm c. 1150 torr d. 978 torr

d. 978 torr

Which of the following is an exothermic process? a. sublimation b. melting c. evaporation d. condensation

d. condensation

A gas sample is collected in a balloon. What happens to the density of the gas sample as the sample is heated?

decreases

never redox reactions. These reactions often take place between substances dissolved in water. In typical reactions, two dissolved compounds react and exchange partners to form two new compounds. The following general form of the equation for double replacement reactions shows the partner-swapping characteristic of the reactions: AX + BY → BX + AY

double replacement reaction

same as double replacement equation

molecular equations

A redox reaction can also be a:

more than one response is correct

High density is characteristics of which state of matter?

more than one response is correct

Potential energy resulting from the attraction of particles...

more than one response is correct

Which of the following equations (not balanced) represents an oxidation‐reduction process?

more than one response is correct

Tests are to be conducted on new anti‐cancer drug and you are to prepare a fresh supply for the human subject studies. You discover that you were able to produce 1.345 g of this substance although it was theoretically possible to make 1.433 g. What was the percent yield for this synthesis? a) 93.859% b) 93.86% c) 94% d) 0.9386%

93.86%

which ion or ions will appear in the following (total ionic) reaction when it is written in net ionic form?

Ba^2+, CO3^2-, H+, and SO4^2-

-A balanced chemical equation is one in which the number of atoms of each element in the reactants is equal to the number of atoms of that same element in the products. A reaction can be balanced by applying the law of conservation of matter. Coefficients *(in below)* are written to the left of each reactant or product in order to achieve balance. *2* H2 (g) + O2 (g) → *2* H2O (l)

Balanced Chemical equations

Acetylene, C2H2, burns according to the following reaction: C2H2+5O2 → 4CO2+2H2O Suppose 1.20 g of C2H2 is mixed with 3.50 g of O2 in a closed, steel container, and the mixture is ignited. What substances will be found in the mixture when the burning is complete? a) CO2 and H2 b) O2, CO2, H2O c) C2H2, CO2, and H2O d) O2, C2H2, CO2, and H2O

C2H2, CO2, and H2O

If 5 grams of CO and 5 grams of O2 are combined according to the reaction 2CO + O2 → 2CO2, which is the limiting reagent? a) CO2 b) O2 c) CO d) CO and O2

CO

-only unionized or insoluble materials and ions that undergo changes as the reaction proceeds are represented. -Any ions that appeared on both the left and right side of the total ionic equation are called spectator ions and are not included in the net ionic equation.

net ionic equations

The modern definition of oxidation is a process:

none of the above

In the equation for an endothermic reaction, the word ʺheatʺ appears:

on the left side

Which of the following is typically an oxidizing agent?

oxygen

Cohesive forces in matter are related to?

potential energy from particle attractions

Single replacement reactions are always:

redox reactions

The word redox is a combination of two words, reduction and oxidation. These two words have multiple meanings when applied to chemical reactions. Oxidation- to combine w/ oxygen, to lose hydrogen, to lose electrons, to increase in oxidation number Reduction-to lose oxygen, to combine with hydrogen, to gain electrons, to decrease in oxidation number

redox reactions

According to the law of conservation of matter, which of the following may NEVER occur as a result of a chemical reaction:

reduction in total mass

Which of the following physical properties would be impossible to determine for a material in the gas state?

surface tension

The mole concept can be applied to balanced chemical equations and used to calculate mass relationships in chemical reactions. Balanced equations can be interpreted in terms of the mole concept and the results used to provide factors for use in factor-unit solutions to numerical problems.

the mole and chemical equations

What property of a liquid such as mercury is used in a liquid in glass thermometer?

thermal expansion

Which of the following is not a common use of the term oxidation?

to gain electrons

all soluble ionic substances are represented by the ions they form in solution. Substances that do not dissolve or that dissolve but do not dissociate into ions are represented by their formulas.

total ionic equations

For the reaction of HCl and NaOH, which of the following type of chemicals will appear in the net equation? a) weak acid b) weak base c) salt d) water

water

How many grams of N2 are required to completely react with 3.03 grams of H2 for the following balanced chemical equation? N2 + 3H2 → 2NH3 a) 1.00 b) 6.00 c) 14.0 d) 28.0

14.0

When the equation below is properly balanced, what coefficient is in front of KCl? KClO3 → KCl + O2 a) 1 b) 2 c) 3 d) 4

2

-Chemical equations are a convenient way to represent chemical reactions. Chemical equations are written in terms of reactants and products. -A symbol is written in parentheses to the right of each reactant and product to indicate the state or form in which the substance exists. Gases are indicated by (g), liquids by (l), solids by (s), and substances dissolved in water by (aq).

Chemical equation

What coefficients are needed to balance the following reaction: CH4 + _____O2 → ____CO2 + _____ H2O a) 4,1,2 b) 2,0.5,1 c)2,1,2 d) none of these

2,1,2

what is the oxidation number of Br in BrO2^- a) -1 b) +1 c) +2 d) +3

+3

what is the oxidation number of Cl in HClO3? a) +2 b) +3 c) +4 d) +5

+5

what is the oxidation number of Mn in KMnO4 a) +9 b) +7 c) +5 d) +4

+7

Oxygen can be prepared in the lab by heating potassium chlorate in the presence of a catalyst. The reaction is 2KClO3 → 2KCl + 3O2. How many moles of O2 could be obtained from one mole of KClO3? a) 1.0 b) 1.5 c) 2.0 d) 3.0

1.5

-all chemical reactions also have changes in energy, all reactions either absorb or give up energy as they proceed. -Chemical reactions that release heat as a product are called *exothermic reactions*. Ordinary combustion of a log in a fireplace is an example of an exothermic reaction. -While it is a physical process and not chemical, a familiar example of an *endothermic process* is the melting of ordinary ice. As the ice melts, heat is absorbed from the air surrounding the ice.

energy and reactions

Two objects are moving with the same velocity, but one has twice the kinetic energy of the other. How does the mass of the object with higher kinetic energy compare to the other objects mass?

it is larger by a factor of 2

How does kinetic energy of a particle change if the particles velocity is increased by a factor of 3?

kinetic energy increases by a factor of 9