Chem 1200 Exam 3: Ch. 8, 9, 10

Balance the equation: Na3PO4 + AgNO3 → NaNO3 + Ag3PO4

Na3PO4 + 3AgNO3 -> 3NaNO3 + Ag3PO4

Elastic collisions are different from the collisions we encounter in life because there is no loss of energy in the system. T/F?

True

If sulfur (S) is found in one of the product molecules it must also be present in one of the reactants. a True b False

True

Pure water in Argentina has the same mass ratio of H to O as water in the U.S. T/F?

True

The only type of interactions that can hold nonpolar molecules together are London forces. T/F?

True

The molar mass of an element is numerically equal to the _________ mass of that element.

atomic

Sketch-in any unshared electrons and then show how a hydrogen bond might form with another methyl alcohol molecule.

b

Which of the following are defined STP values? a 0 K b 0 C c 273 C d 1 torr e 760 torr

b 0 C e 760 torr

The measured pressure in the eye of a hurricane was 654 torr. What is this pressure in atmospheres? a 1.16 atm b 0.861 atm c 2.21 atm d 221 atm e 0.0452 atm

b 0.861 atm 654 torr x (1 atm/760mmHg)

What is the ratio of C atoms to O atoms in carbon dioxide? a 2 carbon atoms for every one oxygen atom; 2:1 ratio b 1 carbon atom for every two oxygen atoms; 1:2 ratio c 2 carbon atoms for every 4 oxygen atoms: 1:2 ratio d more than one correct answer e no correct answer

b 1 carbon atom for every two oxygen atoms; 1:2 ratio

Two containers, A and B, each contain 1.00 L of water at the same temperature. Container A has 2/3 the surface area of container B. After 120 minutes, there is 0.50 L left in container A. How much water is left in container B? a nothing b 1/4 L c 1/2 L d 3/4L e no correct answer

b 1/4 L

Changing the __________ of the chemical formulas will change the identity of the substance.

subscript

The physical state of matter is mainly determined by the _______________ of the substance.

temperature

What conversion factor is needed to convert from grams of a substance to moles of the substance? a. molar mass (g/mol) b. the inverse of the molar mass (mol/g) c. Avogadro's number (particles/mol) d. the inverse of Avogadro's number (mol/particles)

the inverse of the molar mass (mol/g)

Gaseous water molecules below the boiling point of water should be referred to as __________________

vapor

The pressure exerted by the vapor above the liquid in a closed container at equilibrium is referred to as ________ ________

vapor pressure

The difference between evaporation and vaporization of a substance is that __________ occurs at the substance's boiling point while __________ occurs below the boiling point.

vaporization evaporation

If the pressure and amount of gas are held constant, the combined gas law will reduce to ............... . a Boyle's law b Charles's law c Gay-Lussac's law d Avogadro's law e no correct answer

b Charles's law

If carbon (C) is found in all of the reactants it must also be present in all of the products. a True b False

b False

The molar volume of any gas is 22.414 L at any temperature. a True b False

b False

Solve the combined gas law equation for the variable T2. a T2 = (n2 x P1 x V1) / (P2 x V2 x n1 x T1) b T2 = (P2 x V2 x n1 x T1) / (n2 x P1 x V1) c T2 = (n2 x P2 x V1) / (P1 x V2 x n1 x T1) d T2 = (P2 x V2 x n2 x T1) / (n1 x P1 x V1) e no correct answer

b T2 = (P2 x V2 x n1 x T1) / (n2 x P1 x V1)

Why does food cook faster in a pressure cooker than in a conventional pot? a The metal alloy of a pressure cooker traps the heat better. b The pressure cooker has a gas-tight seal so the vapor cannot escape as the cooker is heated. The greater vapor pressure causes the water in the cooker to boil above its normal boiling point. c The pressure cooker has a gas-tight seal so the vapor cannot escape as the cooker is heated. The greater vapor pressure causes the water in the cooker to boil below its normal boiling point.

b The pressure cooker has a gas-tight seal so the vapor cannot escape as the cooker is heated. The greater vapor pressure causes the water in the cooker to boil above its normal boiling point. *The higher temperature will speed up the chemical reactions involved in the cooking process.

Based on the previous question, which unknown value, n or V, must be determined experimentally? a n b V

b V

Why is water different from some of the other substances we encounter naturally? a Water is a "healthy chemical" we ingest regularly. b Water occurs naturally in all 3 physical states. c Much of chemistry is based on water interactions. d more than one correct answer e no correct answer

b Water occurs naturally in all 3 physical states.

In the solid state potential energy (cohesive forces) __________ over kinetic energy (disruptive forces). Solid states has __________ shape and _________ volume Solids have ______ density Solids exhibit _______________ compressibility Solids exhibit a _________________ thermal expansion

dominates -In a solid, the individual particles are not free to move at all temperatures below the melting point. Solid states has DEFINITE shape and DEFINITE volume Solids have HIGH density Due to the compact and orderly packing of particles in a solid, there is virtually no empty space between particles. Solids exhibit VERY LOW compressibility Solids exhibit a VERY SMALL thermal expansion

Boyle's law states that if you reduce the pressure of a given mass of gas at constant temperature to one-fourth the original pressure (P = 1/4 P), the final volume (V) occupied by the gas will be ............... V. a equal to b 1/2 c double d 1/4 e 4 times

e 4 times

760 torr is the exact same as one ___. a one inch Hg b one mm Hg c one atm d 760 mm Hg e more than one correct answer f no correct answer

e more than one correct answer c one atm d 760 mm Hg

Under what circumstances would you use the ideal gas law instead of the combined gas law? a when P and V conditions are constant b when P and T conditions are constant c when T and V conditions are constant d when P, T, and V conditions are constant e when only one set of P, T, and V conditions is given

e when only one set of P, T, and V conditions is given

Changes of state that require input energy are called:

endothermic

If the rate at which the product in a chemical reaction is synthesized equals the rate at which the product decomposes to yield the reactants, the reaction is said to be at _______________________

equilibrium

Changes of state that release energy are called:

exothermic

The molar mass and the __________ mass are numerically the same value.

formula

The accepted abbreviation of the units for the formula mass is amu. What is the accepted abbreviation for the units of the molar mass?

g/mol

Atmospheric pressure ____________ with decreasing altitude

increases

Evaporation:

is the process by which a substance changes from the liquid to the gaseous state at a temperature below its boiling point.

When two or more reactants are added into a chemical reaction, the limiting reagent is the reactant which __________ the actual ________ of product formed.

limits amount

Water has a fixed ratio by ___________ of O atoms and H atoms.

mass

When attempting to convert an empirical formula into an actual chemical formula you must know the _______ ________ of the compounds

molecular mass

How many moles of each gas are present in this mixture inside a 5.00 L container at 25 C? moles of N2 moles of CO2 moles of O2

moles of N2 = 0.156 moles of CO2 = 0.0949 moles of O2 = 0.0809

Elements in a given compound are always found in definite _________

proportions

Chemicals with high vapor pressure evaporate __________

quickly

According to the kinetic molecular theory of matter, the particles which make up a gas are always in constant _________ _________

random motion

According to the kinetic molecular theory of matter, the particles which make up matter are always in constant ______________

random motion

In a chemical reaction an arrow that points from ___________ to ___________ is drawn

reactants to products

The products of a chemical reaction are listed on the ___________ side of a chemical equation

right

When 16.00 g of O are mixed with 2.02 g of H and a complete reaction takes place __________ _____ H2O will be produced

18.02 g

How many grams of CO2 are produced from a reaction which produces 10.52 g H2O? 5 O2 + C3H8 -> 3 CO2 + 4 H2O

19.27 10.52 g H2O x (mol H2O/18.02 g H2O) x (3 mol CO2/4 mol H2O) x (44.01 g CO2/mol CO2) = 19.26963929 (calculator) = 19.27 g CO2 (correct)

What are the correct coefficients for each reactant and product when the following equation is balanced? _____ N2H4 + _______ H2O2 -> _______ N2 + _______ H2O2

1N2H4 + 2H2O2 -> 1N2 + 4H2O

Atoms can be mixed in proper ratios without counting them by simply weighing them. T/F?

True

Boiling points can be classified as a type of physical property of a substance only when the external pressure is defined. T/F?

True

Changing the temperature or pressure will disturb a system which is at equilibrium. T/F?

True

Kinetic Molecular Theory five formal statements:

#1 All Matter is made up of tiny particles (atoms, molecules, and ions) that have definite size, mass, and other unalterable characteristics. #2 Above absolute zero (0 K), all particles are in constant random motion and therefore, possess kinetic energy. Kinetic energy is energy due to motion of matter. Particles transfer kinetic energy to one another through elastic collisions - like billiard balls. #3 Particles interact with each other via attractions and repulsions, and therefore, they possess potential energy. There is potential energy in chemical bonds and the interactions among polar and nonpolar molecules. Electrostatic interactions are attractions and repulsions of charged or partially charged particles. Particles of opposite charge (cations and anions) attract each other. #4 Particles that are in random motion will eventually collide with each other. During the collision energy is transferred via an elastic collision process. Elastic collisions are collisions where no energy is lost to the environment. That is, the sum of the kinetic energies of all participants prior to the collision equals the sum of the kinetic energies of all participants after the collision. #5 The velocity of particles within a system increases as the temperature increases.

Meaning for the following notations: (g) (s) (l) (aq)

(g) - gaseous state (s) - solid state (l) - pure liquid (aq) - aqueous (water-based solution)

Calculate the temperature, in C, of 5.52 moles of a gas held at 923 torr in a volume of 60.5 L. a 162 C b 4.69 C c -111 C d -268 C e no correct answer

-111 C T=PV/nR = (923 torr x 60.5 L)/​[5.52 mol x 62.4 L torr/(mol K)] = 162 K; 162-273 = -111 oC

Empirical formula:

-A chemical formula that has been derived through an experimental process -The empirical formula is the lowest ratio of whole atoms in a compound. But remember --- it may or may not describe the actual ratio of atoms in the compound. --no matter how accurate the data, when you experimentally determine a chemical formula, you often do not get the real chemical formula. This artificial, or possibly real, chemical formula is called the empirical formula. A chemist may determine that the empirical formula for a compound is CH4. However, this chemical formula also represents the lowest ratio of C to H for any compound with a similar composition --- C2H8 or C3H12. We can do some additional experiments to determine the formula mass of the compound and from there we can determine the actual chemical formula of the compound. It may turn out that we really are working with CH4 and not with C2H8 or C3H12.

The vapor pressure can easily be determined with a: Gas pressure inside the container (Pgas) is given by:

-A manometer is a device that uses a mercury-filled U-tube connected to a closed container containing a small amount of the liquid of interest The gas pressure inside the container (Pgas) is given by: Pgas = Patmosphere + ΔP Pgas = Patmosphere - ΔP Always reference the open end (right arm) of the manometer! If higher than the attached side --- add the ΔP value to the barometric pressure! (the gas pressure is greater than the atmospheric pressure) If lower than the attached side --- subtract the ΔP value from the barometric pressure (the atmospheric pressure is greater than the pressure of the gas inside the flask)

The kinetic molecular theory proposes that:

-All particles making up a substance (atoms, molecules, and/or ions) are in constant random motion at all temperatures above 0 kelvin (absolute zero). --Kinetic molecular theory attempts to explain the behavior of the physical states of matter at the atomic or molecular level

Cooking spaghetti noodles to the same consistency would take longer in the Uintah mountains than in downtown New Orleans. T/F?

True

The equation is balanced by changing the:

-Coefficient value of some (or all) of the substances until equal number and types of atoms are present. --Only the coefficient may be changed to balance an equation. -Never change the subscripts of the chemical formulas to balance an equation. --If you change a subscript, you are changing the identity of the substance. Remember, the identity of the reactants and products is a chemical fact of the reaction --- it cannot be changed to suit your needs in balancing the chemical equation.

The Standard Temperature and Pressure (symbol STP) are:

-Defined values used as a reference for all scientists. -The standard temperature is defined as 0 C or 273 K -The standard pressure is defined as 1 atm or 760 mm Hg (torr).

Mole describes

-Describes a heap or pile, a mole is a counting unit based on the number 6.022 x 10^23 --Three moles represent three times the number of particles found in one mole -Avogadro's number of particles (a mole or pile) for any pure substance is equal to its atomic or formula mass in grams rather than amu.

Dipole-dipole interactions:

-Dipole-dipole interactions are electrostatic interactions among polar molecules. These interactions occur due to a positive and negative dipole in the molecules. Similar to a pair of magnets, the molecules involved in this type of interaction can attract each other or, if turned, repel each other. -Dipole-dipole interactions are chaining interactions, the molecules involved can form a network of attractive positive and negative forces. In this manner, the molecules adjust naturally so as to minimize the repulsive forces (negative to negative or positive to positive). --Just as magnets come in different strengths, if the forces are weak, the substance will have a low boiling point --- the stronger the interaction, the higher the boiling point.

In the gaseous state the disruptive forces (kinetic energy) ____________ over the cohesive forces (potential energy). Gases exhibit ___________ shape and _________ volume Gases have ________ density Gases exhibit _________ compressibility Gases exhibit __________ thermal expansion

-Dominate Gases exhibit INDEFINITE shape and INDEFINITE volume Gases have LOW density Gases exhibit LARGE compressibility If sufficient pressure is applied, gas molecules are forced to come into contact with each other, and the gas liquefies. Gases exhibit MODERATE thermal expansion

The law of conservation of mass simply states:

-During a normal chemical reaction with exactly the right amount of ingredients, the resulting total product mass is exactly the same as the total reactant starting mass. In other words, during a normal chemical reaction, mass cannot be created nor destroyed. --The chemical equation is basically a mathematical description of a chemical reaction using the molecular or ionic formulas rather than words to describe the changes that are happening in a chemical reaction.

Endothermic:

-Endothermic is a term that describes an exchange of energy. In the case of phase changes, the word endothermic refers to a change of state that requires the input of heat energy. -Endo for energy in! -Melting, evaporation, and sublimation are endothermic processes.

Kinetic energy is:

-Energy due to motion of matter. Particles transfer kinetic energy to one another through elastic collisions - like billiard balls. --Kinetic energy is a disruptive force As the average kinetic energy increases, particles of a substance move faster and farther apart from each other. The particles become increasingly independent of each other.

Exothermic:

-Exothermic is a term that describes an exchange of energy. In the case of phase changes, the word exothermic refers to a change of state that results in heat energy being released. -Exo for energy out (exit)! -Freezing, condensation, and deposition are exothermic processes.

In the liquid state __________ force (disruptive, cohesive) dominates. Liquid states has __________ shape and _________ volume Liquid states have ___________ density Liquid states have ____________ compressibility Liquid states exhibit ___________ thermal expansion

-Neither --The kinetic energy and the potential energy have similar magnitude and balance each other --- liquids exhibit both fluidity and cohesiveness. Liquid states has INDEFINITE shape and DEFINITE volume Liquid states have HIGH density Liquid states have SMALL compressibility As the particles in a liquid are in physical contact, there is not much space in between them that can be eliminated by increasing the pressure on the system. Liquid states exhibit SMALL thermal expansion Increasing the temperature increases the kinetic energy (disruptive force). The particles will slide more freely about each other; thus they will occupy somewhat more space

Potential energy is

-Potential energy is stored energy due to position, condition, and/or composition. --There is potential energy in chemical bonds and the interactions among polar and nonpolar molecules. Electrostatic interactions are attractions and repulsions of charged or partially charged particles. Particles of opposite charge (cations and anions) attract each other, whereas particles of like charge repel each other. -Potential energy is a cohesive force. Potential energy maintains stability and order within a system by keeping the particles that make up a substance close together.

Pressure is __________ related to the force and ____________ to the area

-Pressure is DIRECTLY related to the force and INDIRECTLY to the area. If you increase the force --- the pressure increases. If you decrease the force --- the pressure decreases. If you increase the area --- the pressure decreases. If you decrease the area --- the pressure increases

Pressure is defined mathematically as the:

-Ratio of a force divided by the area of the surface to which the force is applied --Pressure is the result of constantly moving molecules colliding with the inside surface of a container. The pressure of a gas depends on the frequency and the force of the collisions between the molecules and the container walls. When the energy and frequency of the collisions increases, the pressure increases.

Gas laws:

-Simple mathematical equations that relate the pressure, temperature, volume, and amount of a gas to each other --The behavior of gases is very predictable and can be described by simple quantitative relationships

London forces or induced dipoles

-Special electrostatic interactions among polar and nonpolar molecules. These dipoles are induced by the presence of another molecule and are the weakest of the intermolecular forces. Substances that are held together by only London forces have low boiling points. --The strength of the attractive dipole is dependent on the total number of these interactions among the participants in a molecular "party." If there is a large number of attractive interactions, the molecular party holds together more tightly.

Hydrogen bonding (H-bonds) interactions

-Special electrostatic interactions among polar molecules that have the unique ability to form a special attraction to a hydrogen atom through a pair of lone (nonbonding) electrons. -These interactions are generally much stronger than normal dipole-dipole interactions. However, only certain types of molecules can actually participate in the formation of hydrogen bonds. H-bonds can only form between a hydrogen atom and the lone pair of electrons on a F, O or N atom on another molecule.

Formula mass (fm) ex. what is the mass of water? what would the percent composition of H, O in water be?

-Sum of the atomic masses of all the atoms in a formula unit of an ionic compound --The formula unit is the lowest whole-number ratio of ions that results in an uncharged compound -H2O average mass of an O atom (periodic table) = 16.00 amu average mass of a H atom (periodic table) = 1.01 amu (2 × 1.01 amu) + (1 × 16.00 amu)= 18.02amu Percent composition: -- (16.00amu ​/ 18.02 amu total) × 100= 88.79%​​​ --For a binary compound like water the remaining mass of 2.02 amu must be H! (2.02 amu / 18.02 amu total) × 100 = 11.2%

The physical state of a substance depends on three factors:

-Temperature -Pressure -Chemical identity --The major factor that determines the physical state of a substance at a given temperature and pressure must be its chemical identity.

Percent composition:

-The calculated mass ratio for each element present in a given compound -- The percent composition of a compound is determined by calculating the mass percentage for each element present in the compound, wherein all of the individual values are constant--- law of definite proportions --- and add up to a total of 100%. --Ex. The percent composition of water is always 11.21% by mass H and 88.79% by mass O. Let's say that 100.0 g of pure water is decomposed completely by electrolysis into: 11.21 g of hydrogen gas and 88.79 g of oxygen gas The mass ratio of H in H2O is --- 11.21 g H/100 g water = 11.21% (m/m) hydrogen The mass ratio of O in H2O is --- 88.79 g O/100 g water = 88.79% (m/m) oxygen 200.0 g of water, in this case, we should be able to isolate 22.42 g of hydrogen gas and 177.58 g of oxygen gas. The mass ratio of hydrogen is the same --- 22.42 g/200.0 g = 11.21% (m/m) hydrogen The mass ratio of oxygen is the same --- 177.58 g/200.0 g = 88.79% (m/m) oxygen Conclusion --- 11.21 g of H mixed with 88.79 g of O would make 100.0 g of water. Likewise --- 22.42 g of H mixed with 177.58 g of O would make 200.0 g of water.

Parts of a chemical equation

-The ingredient(s) or starting material(s) is/are called reactant(s); reactants are listed on the left side of the chemical equation. Also called Chemical reagents. -The chemical species resulting from the reaction is/are called product(s); products are listed on the right side of the chemical equation. Also listed as experimental fact Reactants -> Products Reactant 1 + Reactant 2 → Product 1 + Product 2 -A small subscript (aq), (g), (s), (l) on the right side of a reactant or product is simply a symbol used to describe the physical form

Molar mass:

-The mass of 1 mole (pile) of a given substance. --The molar mass of a compound is the mass, in grams, which is numerically equal to the formulas mass of the compound. If you can calculate the formula mass of a compound in amu using the periodic table, you have calculated the molar mass as well. --Since Avogadro's number of particles for any substance is numerically equal to the formula or atomic mass in grams, the formula or atomic mass is often called the molar mass of a substance grams/1 mol. --Molar masses due have error in them! (it has significant figures)

Molecular formula:

-The molecular formula is a chemical formula that gives the actual number of atoms present in one molecule of a compound. --The actual chemical formula is also called the molecular formula or true formula.

Atmospheric or Air Pressure How is atmospheric pressure measured?

-The molecules and atoms in the atmosphere exert pressure on all objects in the atmosphere -Atmospheric pressure is measured with a device invented by the Italian physicist Evangelista Torricelli (1608-1647) in 1643 called a barometer

Vapor pressure: Vapor pressure depends on just two things:

-The pressure exerted by the vapor of the liquid above the body of the same liquid when the vapor and the liquid are in equilibrium -The temperature and -The chemical identity of the substance --For example, water molecules have a strong attraction for each other, and gasoline molecules have comparatively weak attractions. Thus, water has a lower vapor pressure than gasoline at the same temperature.

Proust's law --- the law of definite proportions:

-The ratio or proportion of the different elements, by mass, in a given pure compound is fixed and independent of its source and method of preparation -- H2O and H2O2 are different compounds with different mass ratios of elements If two compounds have the same mass ratio of the same elements, this does not mean that they are necessarily the same compound -- C4H10 and C8H20 are different compounds with the same mass ratios of elements

The ideal gas law describes:

-The relationship among the four variables pressure (P), volume (V), temperature (T), and moles of gas (n) for gases at one set of conditions. An ideal gas is a gas that exactly obeys the gas laws over all temperatures and pressures. -If a gas is maintained in a rigid container at one temperature, then there is no change in pressure and of course, unless you add more gas, there is no increase in the number of moles. The equation is made equivalent to a constant (R) which is called the ideal gas constant. PV/ Tn = R Numerical value for R: 1.00atm × 22.414 L​​ / 1.00 mol x 273 K =0.0821 atm L/mol K The value of R can also be expressed in units of torr. 0.0821atm × (atm L/mol K) × (760 tor /1 atm) = 62.4 L torr/mol K

Molecular mass

-The sum of the masses of all the atoms in a molecule

The rate of evaporation of a liquid is dependent of three things:

-The surface area of the liquid -The identity of the liquid -The temperature of the system -Evaporation is a surface phenomenon. The molecules below the surface are "buried" and surrounded at all sides by other molecules that attract them. This makes their escape very unlikely. The rate of evaporation is directly related to the surface area of the liquid The greater the surface area, the faster the process of evaporation.

A sample of gas occupies a volume of 1.25 L and has a pressure of 0.0250 atm at 0 C. If the volume is changed to 250.0 mL at the same temperature, what will be the new pressure, in atm, of the gas?

0.125 P2 = P1 x V1/V2 = 0.0250 atm x 1.25 L/0.2500 L= 0.125 atm

How many moles of Fe(NO3)2 are there in a 135.89 g sample of this compound? NOTE: Assume that all given numbers are from measurements. Use a periodic table that lists atomic masses to two decimal places. Solve the problem, then use significant figure rules to properly round and report your answer in decimal notation. Do not include units, letters and/or symbols.

0.75549 135.89 g x 1 mol/179.87 = 0.75549 mol

A balloon contains 1.75 moles of Xe and has a volume of 1.20 L at a given temperature and pressure. If 0.50 moles of Xe are allowed to leak out of the balloon without changing the temperature and pressure conditions, what will be the new volume, in L, of the balloon?

0.857 V2 = V1 x n2/n1 = 1.20 L x 1.25 mol/1.75 mol = 0.8571428571 L (calculator) = 0.857 L

How many atoms of N are required to make one molecule of Tylenol?

1 C8H9O2N

What would happen if you mixed 115.00 g of O with 11.21 g of H and a complete reaction takes place, how many grams of water will be produced?

100.00 115.00 g of O + 11.21 g of H will supply just enough H to make 100.0 g of water. Since I only need 88.79 g of O for a complete reaction, there must be excess O and I will have 26.21 g of O remaining unreacted. Notice that the H limits the amount of water that can be produced not the O. This is like making a sandwich with plenty of bread and only 8 slices of meat. The total number of sandwiches that can be made is 8 because the meat is limiting.

How many grams of Mg will be needed to make 5.000 kg MgCl2? Mg + 2 HCl → MgCl2 + H2

1277 5.000E3 g MgCl2 x (mol MgCl2/95.21 g MgCl2) x (1 mol Mg/1mol MgCl2) x 24.31 g Mg/mol Mg = 1276.6516512 (calculator) = 1277 g Mg (correct)

How many grams of H are there in 55.69 g of methane, CH4?

14.0 55.69 g methane x (mol methane/16.05 g) x (4 mol H/mol methane) x (1.01 g H/mol H) = 14.017919 (calculator) = 14.0 g H (correct)

Calculate the formula mass of Tylenol - C8H9O2N from a periodic table that lists atomic masses to two decimal places. What is the percent composition of each?

151.18 C = (8x12.01); H = (9x1.01); O = (2x16..00); N = (1x14.01); 96.08+9.09+32.00+14.01=151.18 %C: 63.55 %H: 6.01 %O: 21.17 %N: 9.27

The molar mass of CH expressed with ± 0.01 accuracy is

16.05 g/mol

How many grams of H2O2 will exactly react with 76.00 g of N2H4? N2H4 + 2H2O2 -> N2 + 4H2O

161.3 76.00 g of N2H4 x (1 mol N2H4/32.06 g of N2H4) x (2 mol H2O2 /1 mol N2H4) x (34.02 g H2O2/ mol H2O2) = 161.2925764 (calculator) = 161.3 g HO (correct)

How many molecules are there in 55.69 g of methane, CH4? NOTE: Assume that all given numbers are from measurements. Use a periodic table that lists atomic masses to two decimal places. Solve the problem, then use significant figure rules to properly round and report your answer in scientific notation. Do not include units.

2.090E24 55.69 g x (mole/16.05 g) x (6.022x10^23 molecules/mol) = 2.089502679x10^24 (calculator) = 2.090x10^24 molecules (correct)

A sample of gas occupies a volume of 4.00 L at 40 C and a pressure of 1.00 atm. Calculate the volume, in L, if the pressure is increased to 1.75 atm at constant temperature.

2.29 V2 = V1 x P1/P2 = 4.00 L x 1.00 atm/1.75 atm = 2.29 L (3 sig figs)

What is the mass contained in one mole of Mg atoms? NOTE: Express your answer in decimal notation to ± 0.01 accuracy. Do not include units.

24.31 24.31 g is the mass of one mole of Mg

The number of "two nuts per bolt" combinations that can be made with 56 nuts and 40 bolts is

28 56/2 = 28

Balance the equation: NaHCO3 + H2SO4 → Na2SO4 + H2O + CO2

2NaHCO3 + H2SO4 -> Na2SO4 + 2H2O + 2CO2

A single methyl alcohol molecule can form a maximum of ............... H-bonds with other methyl alcohol molecules.

3

A single methyl alcohol molecule can form a maximum of ............... H-bonds with water molecules.

3

For the chemical reaction above, NO2 must be added into the reaction at a ratio which is ________ times the amount of water.

3 For the chemical reaction above, NO[math]_{2}[/math] must be added into the reaction at a ratio which is

What is the molar ratio of oxygen, O2, to sulfur dioxide, SO2, in the following balanced equation?3 O2 + CS2 → CO2 + 2 SO2

3 moles O2/ 2 moles SO2 2 moles SO2/ 3 moles O2

How many pieces of paper are found in a 1/2 mole of paper? NOTE: Express your answer in scientific notation with 4 significant figures. Do not include units.

3.011E23 1/2 is a simple fraction, it is an exact number, therefore 0.5 x 6.022x10^23 = 3.011x10^23

How many moles are there in 55.69 g of methane, CH4? NOTE: Assume that all given numbers are from measurements. Use a periodic table that lists atomic masses to two decimal places. Solve the problem, then use significant figure rules to properly round and report your answer in decimal notation. Do not include units, letters and/or symbols.

3.470 55.69 g x mole/16.05 g = 3.469781931 (calculator) = 3.470 (correct)

If a mixture of N2, O2 and CO2 has a pressure of 1235 torr, what is the partial pressure of O2 in torr, if N2 and CO2 have partial pressures of 581 torr and 353 torr, respectively?

301 1235= 581 + 353 + x; x = 1235 - 581 - 353 = 301 torr

A sample of CO gas has a volume of 1.00 L at a pressure of 1.00 atm and a temperature of 35 C. What is the volume, in mL, of this gas sample at a temperature of 105 C and a pressure of 4.00 atm?

307 V2 = V1 x P1/P2 x T2/T1 = 1.00 L x 1.00 atm/4.00 atm x 378 K/308 K = 0.3068181818 L (calculator) = 307 mL

At constant pressure, a 325 mL sample of O2 gas is warmed from 21 C to 43 C. What is the new volume, in mL, of the O2 gas?

349 V2 = V1 x T2/T1 = 325 mL x 316 K/ 294 K = 349.3197279 (calculator) = 349 mL

According to the periodic table, the mass of 6.022 x 10 chlorine atoms is ___________ ______________

35.45 g

If you are given 2 moles of pure water, how much should it weigh in grams? (one mole of water molecule is 18.02)

36.04 2 x 18.02 = 36.04

If the cost of HCl is $1,000.00 per kilogram and the cost of magnesium is $10.00 per kilogram, how much will it cost to produce 5.000 kg MgCl2? There is 3.829 kg HCl and 1.277 kg Mg in 5.00 kg of MgCl2.

3841.77 (3.829 kg HCl x $1000.00/kg HCl) + (1.277 kg Mg x $10.00/kg Mg) = $3829.00 + $12.77 = $3841.77

What are the correct coefficients for each reactant and product when the following equation is balanced? _____ CO + _______ NaCN -> ______ Na2CO3 + _____ C + _____ N2

3CO + 2NaCN -> 1Na2CO3 + 4C + 1N2

Calculate the volume, in L, occupied by 1.50 moles of a gas at 0.990 atm pressure and a temperature of 60 C.

41.4 V = nRT/P = (1.50 mol x 0.0821 atm L/mol K x 333 K )/0.990 atm = 41.42318182 (calculator) = 41.4 L (correct)

How many grams of C can be produced by reacting 100.0 g of NaCN with plenty of CO? 3 CO + 2 NaCN -> Na2CO3 + 4C + N2

49.01 100.0 g NaCN x (mol NaCN/49.01 g NaCN) x (4 mol C/2 mol NaCN) x (12.01 g C/mol C) = 49.01040604 (calculator) = 49.01 g C (correct)

What are the correct coefficients for each reactant and product when the following equation is balanced? ____ O2 + _____C3H8 -> ____CO2 + _____H2O

5 O2 + 1 C3H8 -> 3 CO2 + 4 H2O

Assuming you have plenty of HCl, what mass of Al, in g, is required to produce 256.0 g AlCl3? 6 HCl + 2 Al -> 3 H2 + 2 AlCl3

51.80 256.0 g AlCl3 x (mol AlCl3/133.33 g AlCl3) x (2 mol Al/2 mol AlCl3) x (26.98 g Al/mol Al) = 51.80289507 (calculator) = 51.80 g Al (correct)

Avogadro's number How does it relate to grams

6.022 x 10^23 amu Jan Baptiste Perrin actually calculated the number of particles in a given mass of gas and called the value Avogadro's number There are 6.022 x 10^23 amu/g -Avogadro's number is very important to chemists because it links the microscopic atomic world (amu scale) to the macroscopic world (gram scale) of the laboratory where we actually work. -Notice that all the gram masses use the same number as the atomic or formula mass. One atom of carbon is 12.01 amu (average mass), one mole of carbon atoms is 12.01 g. One water molecule has a mass of 18.02 amu, whereas one mole of water molecules is 18.02 g.

If an M&M's® candy weighs 1.000 g and there are 453.6 g/lb, how many tons of M&M's® are there in one mole of M&M's®?

6.638 x 10^17 tons of M&M's® 6.022x10^23 g x (1 lb/453.6 g) x (ton/2000 lb) = 6.638x10^17 tons

A sample of O2 with a volume of 25.0 L at 28 C and 1.00 atm is reacted with excess N2 to produce nitrogen monoxide (NO). The equation for this reaction is O2 (g) + N2 (g) → 2 NO (g) How many grams of NO are produced?

60.7 60.6 60.8 n = PV/RT = (1.00 atm x 25.0 L)/​[(0.0821 atm l /mol K) x 301 K] x (2 mol NO/1 mol O2 x (30.01 g NO/mol NO) = 60.7192428 (calculator) = 60.7 g NO (correct)

A pressurized can of whipping cream contains gas at a pressure of 1.10 atm at 23 C. If the can is able to withstand an internal pressure of 3.30 atm before it explodes, to what temperature, in degrees Celsius, can this can be heated before it explodes?

615 T2 = T1 x P2/P1 = 296 K x 3.30 atm/1.10 atm = 888 K; 888 -273 = 615 C

If I want to make 100.0 g of Tylenol, how many grams of carbon will I need?

63.55 g C 100.0 g Tylenol x 96.08 g C/151.18 g Tylenol = 63.55 g C

If you performed the reaction in question 10.3_Q22 above by reacting 100.0 g of NaCN in the presence of plenty of CO and isolated 33.09 g of C, what is the percent yield of this reaction? You already calculated how you can make in theory in question 10.3_Q26.

67.52 (33.09 g C/49.01 g C x 100 = 67.5168333 (calculator) = 67.52 %

If I wanted to make 12.00 g of Tylenol, how many grams of carbon would I need?

7.626 63.55 x 12.00 /100.0 = 7.626 or 12.00 g Tylenol x 96.08 g C/151.18 g Tylenol = 7.626

What is the mass contained in three moles of Mg atoms? NOTE: Express your answer in decimal notation to ± 0.01 accuracy. Do not include units.

72.93 3 x 24.31 g = 72.93 g is the mass of three moles of Mg

If the mercury level in the left arm of the U-tube of the manometer shown above is 25.0 mm lower than the level in the right arm open to the atmosphere and the barometric pressure is 765.2 mm Hg, what is the pressure of the gas inside the flask?

790.2 765.2 mm Hg + 25.0 mm Hg

How many H atoms are there in 55.69 g of methane, CH4?

8.358E24 55.69 g methane x (mol methane/16.05 g) x (4 mol H/mol methane) x (6.022x10^23 H atoms/mol H) = 8.358010717x10^24 (calculator) = 8.358x10^24 H atoms (correct)

Vapor

A vapor is the gaseous phase of a substance that is normally a liquid or a solid at the given temperature and pressure conditions.

Theoretical and Actual Yield Equation:

Actual yield mass/ calculated theoretical mass ​×100= percent yield --In the case of a limiting reagent question, the theoretical yield is based on the smallest calculated amount of product that can be formed from the given starting quantities of reactants.

Actual yield:

After performing the chemical reaction and isolating the product, the actual weighed amount of product is called the actual yield --The actual yield should always be lower than the theoretical yield or something is wrong with the calculation

When a hydrocarbon is burned in a combustion furnace, where does all the H go?

All the hydrogen ends up in water in the water water H2O it reacts with oxygen to form water it reacts with oxygen to from H2O

Which period 3 elements are gases at room temperature and pressure?

Ar Cl

Evaporative cooling:

As the molecules with higher kinetic energy evaporate, the average kinetic energy of the remaining molecules is inherently lower. The temperature of the remaining liquid decreases as the higher energy vapor molecules escape to the atmosphere.

Intermolecular forces: Three different types of interactions that occur among molecules called intermolecular attractive forces:

Attractive forces between molecules --We can hypothesize that the molecules within a substance hold onto each other, and that the strength of this attraction is different in different compounds --- a type of molecular Velcro Dipole --- dipole interactions Hydrogen bonds London forces or induced dipoles

Boyles Law: Charles's Law: Gay-Lussac's Law: Avogadro's Law: Ideal law:

Boyles Law: P1V1 = P2V2 (inverse relationship- as volume decreases pressure increases) Charles's Law: V1/ T1 = V2/T2 (direct relationship) Gay-Lussac's Law: P1/T1 = P2/T2 (direct relationship) Avogadro's Law: V1/n1 = V2/n2 PV = nRT (kelvin temperature)

Which two elements are liquids at room temperature and pressure? a B b Br c Mc d Hg e H2O f H2O2

Br Hg

A compound with an unknown formula is known to made up of C, H, O, N, and Cl. Given the following percent by mass data and a molecular mass of 375.93, calculate the actual chemical formula for this compound. C = 70.28%; H = 8.044%; O = 8.512%; N = 3.726%; Cl = 9.431%

C22H30O2NCl

What is the empirical formula of a compound that is 54.33% C, 9.15% H, and 36.32% O?

C2H4O

In what sequence do you have to do the steps below in order to find the actual chemical formula from empirical information. Write the actual chemical formula Determine the empirical formula Determine the mass of the empirical formula Divide the actual formula mass by the mass of the empirical formula

Determine the empirical formula Step 1 Determine the mass of the empirical formula Step 2 Divide the actual formula mass by the mass of the empirical formula Step 3 Write the actual chemical formula Step 4

Charles determined that the kelvin temperature and volume of a gas are ____________ proportional

Directly proportional --When one variable increases, the other increases proportionally Charles's law states that the volume of a fixed mass of gas is directly proportional to its kelvin temperature at constant pressure. Charles's law can be expressed as: V1/T1= V2/T2

Kinetic energy is expressed by the following mathematical equation:

Ekin = 1/2 mass x velocity ^2 Ekin = 1/2 mv^2 The velocity (meters/second) component is a squared factor in kinetic energy!

Carbon dioxide is always a gas. T/F?

False

London forces are the strongest of the three intermolecular forces described above. T/F?

False

The actual yield can be calculated using stoichiometry and a balanced chemical equation. T/F?

False

The molar mass is used to calculate the actual number of particles in a certain mass. T/F?

False You need to use Avogadro's number to calculate the number of particles.

What are the predicted products of a combustion reaction involving a hydrocarbon when oxygen is not limiting and only C, H or C, H and O are present in the molecule?

H2O and CO2

Liquids have ............... density, ............... compressibility, ............... thermal expansion, ............... shape, and ............... volume.

HIGH density SMALL compressibility SMALL thermal expansion INDEFINITE shape DEFINITE volume

"Solids have ............... density, ............... compressibility, ............... thermal expansion, and ............... shape and volume."

HIGH density VERY LOW compressibility VERY SMALL thermal expansion FIXED shape and volume

When a liquid is exposed to the atmosphere in an open container, it will evaporate completely. However, in a closed container, the rate of evaporation will be:

High at first and then eventually, there will be no change in the apparent liquid level --The lid on the container prevents the evaporated molecules from leaving the container. The fast moving-vapor molecules will collide with the container walls, each other, and the surface of the liquid. As the collisions take place, the molecules eventually lose some energy. As more molecules evaporate, the space above the liquid level available to the vapor molecules becomes crowded and the likelihood of being captured by the liquid surface increases. In the recapturing process, the molecules change from the gas phase back to the liquid. This is the opposite of evaporation and is called condensation. Once the level of liquid in a closed container remains constant, the rate of evaporation must be equal to the rate of condensation.

Percent yield:

How close a chemist comes to isolating the theoretical amount of product from an actual experiment is called the percent yield. --The actual yield should always be lower than the theoretical yield or something is wrong with the calculation

With empirical formulas do you round decimal numbers?

If you have decimal numbers that can be recognized as a simple fraction --- do not round to the nearest whole number! x.3333, x.2501, x.5011, x.6778 or x.7533 --- where x is any whole number. Assume that these values are close to some whole number plus 1/3, 1/4, 1/2, 2/3 or 3/4, respectively.

The vapor pressure of a liquid _________ with temperature

Increases --As the temperature increases, more particles will have sufficient kinetic energy to enter the vapor phase. As more particles evaporate, the vapor pressure increases as well. Upon further heating, the temperature will rise in the body of the liquid until a point is reached where heating does not change the temperature of the liquid anymore. The molecules in the body of the liquid are now ready to convert over to a gas. Any further energy added to the system will be used to change the liquid into a gas rather than increase the temperature of the liquid.

Boyle's law states that there is an ___________ relationship between the pressure and volume of a fixed mass of gas at constant temperature (in kelvin).

Inverse When using any gas law, the temperature must be expressed in the kelvin scale. Mathematically, Boyle's law can be expressed as: P1V1 = P2V2

When a hydrocarbon is burned in a combustion furnace, where does all the C go?

It all ends up being part of the CO2 produced.

What is the magnitude of a gram compared to the magnitude of an amu?

It takes 6.022 x 10^23 amu to make one gram.

The volatility of a liquid refers to its:

Its readiness to evaporate or form a vapor at a given temperature --Chemicals with high vapor pressure are said to be volatile. Chemicals with low vapor pressure are said to be non-volatile.

Gases have ............... density, ............... compressibility, ............... thermal expansion, ............... shape, and ............... volume.

LOW density LARGE compressibility MODERATE thermal expansion INDEFINITE shape INDEFINATE volume

Gas pressure is measured in the same way as a vapor pressure --- with a ___________

Manometer The gas pressure inside the container (Pgas) is given by: Pgas = Patmosphere + ΔP (If the Hg in the right arm is higher, then the ΔP is positive and added to the atmospheric pressure) Pgas = Patmosphere - ΔP (If the Hg in the left arm is higher, then the ΔP is negative and subtracted from the atmospheric pressure)

Particles moving at high speed have ______________ energy. The energy associated with the composition of a substance is ___________ energy. Cohesive forces are associated with ___________ energy. Kinetic energy is associated with a ___________ force.

Particles moving at high speed have HIGH KINETIC energy. The energy associated with the composition of a substance is POTENTIAL energy. Cohesive forces are associated with POTENTIAL energy. Kinetic energy is associated with a DISRUPTIVE force.

When can you use the molar volume of a gas to calculate the number of moles of a gas?

STP

Boiling is a:

Special case of vaporization where the change of phase (from the liquid to vapor) occurs throughout the body of the liquid. This process occurs only when the vapor pressure of the liquid is equal to the external atmospheric pressure. --In an open container, when the vapor pressure of a liquid equals the pressure of its environment, a very rapid evaporation process called boiling occurs within the body of the liquid.

Read the following question and without actually trying to solve the problem, decide which reactant or product would be labeled "substance A" and which would be labeled "substance B" according to the flowchart presented above. Given a 35.00 g sample of AgNO3, how much AgCl could be produced if plenty of HCl was added to the following reaction? AgNO3 + HCl → AgCl + HNO3 Substance A: Substance B:

Substance A: AgNO3 Substance B: AgCl

1 atm = 760 mm Hg or 760 torr --- (76.0 cm in a barometer) is defined as:

The average barometric pressure at sea level --This equivalency is considered exact by definition and will not limit significant figures in pressure conversions.

Boiling point: The boiling point depends on two things:

The boiling point of a liquid is defined as the temperature at which the boiling process takes place. The boiling point is a physical property and characteristic of a pure substance. The boiling point depends on two things: -The external pressure and -The chemical identity of the liquid

What is the molar mass of CO2?

The mass of one CO2 molecule is: 12.01 amu + (2 x 16.00 amu) = 44.01amu Therefore, the mass of one mole of CO2 molecules is 44.01 g Molar mass of CO2 = 44.01 g/mol

When a chemical equation is balanced the

The number and types of atoms found on the left side will exactly match the number and types of atoms on the right side

Decomposition

The process of breaking the chemical bonds which hold the different atoms together in a compound -- If we decompose water with electricity, we get hydrogen and oxygen (both as a gas)

Limiting reagent

The reactant that is used-up completely will limit the amount of product formed in the reaction

For the previous question (10.9_Q46), what is the actual chemical formula if the mass of the compound is 97.16 amu?

The same. The empirical and actual formula are identical.

Stoichiometry is:

The study of the quantitative relationships or ratios between the substances involved in a chemical reaction. The smallest whole-number ratio of coefficients is used to derive stoichiometric ratios which can be used as conversion factors between all participants in a chemical reaction.

The normal boiling point is:

The temperature at which a liquid boils when exposed to an external pressure of 1 atm (atmosphere). 1 atm is defined as the average barometric pressure at sea level. Therefore, the normal boiling point is really the temperature at which a substance boils at sea level. --Just as lower pressure lowers the boiling point, higher pressure increases the boiling point

Dalton's law of partial pressure states:

The total pressure of a mixture of gases is a summation of the partial pressures of all the gases present in the mixture. Mathematically Dalton's law is Ptotal = P1+P2 +P3 + ............... where each individual pressure is defined by the ideal gas law: P= nRT/ V Therefore: Ptotal​= R T​/V (n1​+n2​+n3​+ ........) OR Ptotal​= ntotal​ R T​​​/ V

The molar volume of a gas is:

The volume occupied by one mole of a gas --According to Avogadro's law, the molar volume is the same for all gases at the same temperature and pressure, regardless of their chemical identity. Thus, the molar volume of any gas at STP equals 22.414 L.

It is possible that two different compounds happen to have the same percent composition of elements. T/F?

True If two compounds have the same mass ratio of the same elements, this does not mean that they are necessarily the same compound -- C4H10 and C8H20 are different compounds with the same mass ratios of elements

Simultaneous reactions:

Two reactions simultaneously in the same reaction vessel --If both reactions produce a common product, then the total amount of that product will be calculated using two independent chemical equations and then adding the final results together for a total. --If the simultaneous reactions produce different products (no common product) then they are considered independent, and calculations are performed using two different chemical equations.

What is steady-state condition or equilibrium?

Whenever the rates of two opposing processes are the same --A system in equilibrium is not static, it is dynamic. The evaporation and condensation still occur, but they balance each other such that no net change is observed. --Once a system is at equilibrium, it will remain in this state until the temperature and/or the pressure are/is changed. If a closed system in equilibrium is heated, the liquid level will start to drop until a new equilibrium is reached. At that point, the liquid level will remain constant.

The coefficient is a:

Whole number used to describe the number of molecules or atoms that are needed to participate in an exact reaction --The coefficient is used like the number of eggs or cups of milk required to make a cake.

Can you have a decimal number when you are talking about moles? What about in the molecular level?

Yes, you can have a decimal number with moles. No, you cannot have a decimal number at the molecular level. There is no such thing as 1/2 a molecule

In the reaction we just discussed, how many moles H2 gas are produced for every 1 mole of Mg and 2 moles of HCl? a 1 mole H b 2 moles H c 3 moles H d 4 moles H e no correct answer

a 1 mole H

A 5850 ft^3 quantity of natural gas measured at STP was purchased from the gas company. Only 5625 ft^3 were received at the house. Assuming that all the gas was delivered (no leaks), what was the temperature, in degrees Celsius, at the house if the delivery pressure was 1.10 atm? a 16 C b -15 C c 12 C d 21 C e no correct answer

a 16 C T2 = 273 K x 1.10 atm/1.00 atm x 5625 ft3/5850 ft3 = 288.75 K; 288.75 - 273.15 = 16 oC

The combined gas law is a mathematical combination of what? a Avogadro's law b Gay-Lussac's law c Charles's law d Lavoisier's law e Boyle's law

a Avogadro's law b Gay-Lussac's law c Charles's law e Boyle's law

Why are dipole/dipole interactions said to be "chaining interactions?" a Molecules with a dipole will arrange is such a way as to build a network that maximizes attractions and minimizes repulsions. b Molecules with a dipole will arrange is such a way as to build a network that minimize attractions and maximize repulsions.

a Molecules with a dipole will arrange is such a way as to build a network that maximizes attractions and minimizes repulsions.

Which of the reactants or products in the reaction above is presented as a gas? a NO2 b H2O c HNO3 d NO e no correct answer

a NO2 d NO

During a normal chemical reaction, the mass of the products and any leftover material always equals the mass of the starting materials. a True b False

a True

The molar volume applies to any gas at STP, regardless of the composition of the gas. a True b False

a True

If you want to calculate R, what are the four things you need to remember? a V = 22.4 L at STP b T = 273 K at STP c n = 1.00 mol d P = 1.00 atm at STP e P = 760.0 atm at STP

a V = 22.4 L at STP b T = 273 K at STP c n = 1.00 mol d P = 1.00 atm at STP

What factor(s) may increase the gas pressure inside the flask? a an increase in temperature b a decrease in temperature c the addition of more gas to the flask d the removal of some gas from the flask e increasing the volume of the flask (assuming that flask wall is not rigid)

a an increase in temperature c the addition of more gas to the flask

Avogadro's law indicates that the volume and amount of a gas are ............... proportional. a directly b inversely

a directly Avogadro's law states that at the same temperature and pressure, equal volumes of gases contain equal numbers of molecules. In other words, the volume of a gas is directly proportional to the number of molecules (moles) of gas present at constant temperature and pressure. V1/n1​​​ = V2/n2​​​

In which physical state do the particles have the greatest kinetic energy and the disruptive forces dominate? a gaseous b liquid c solid

a gaseous

Over inflating a tire is more dangerous with a ............... load. a heavy b light

a heavy

Over inflating a tire is more dangerous in ............... weather. a hot b cold

a hot

At STP, in a flexible container, which unknown is set at a fixed value, n or V? a n b V

a n

One torr is the exact same unit as ............... . a one mm Hg b 760 mm Hg c one inch Hg d one atm e more than one correct answer f no correct answer

a one mm Hg

What variables are used by the gas laws to describe the behavior of gases? a pressure b temperature c volume d density e amount

a pressure b temperature c volume e amount (moles= n)

What factors affect vapor pressure? a temperature b surface area c external pressure d chemical identity

a temperature d chemical identity

The problem with knowing the number of atoms or molecules in a given sample of a pure substance is __________ a that the particles are too small to see b that there are too many to physically count them c that the number of particles is not constant d no correct answer

a that the particles are too small to see b that there are too many to physically count them

What two pieces of information or data are required to count particles by weighing? a the total mass of all particles present b the total volume of the particles present c the average mass of each particle present d the average volume of each particle present

a the total mass of all particles present c the average mass of each particle present

Compared to water, would you consider rubbing alcohol to be volatile or nonvolatile? a volatile b nonvolatile

a volatile

Indicate which of the following statements is true. a) In a pure compound, the elements are always present in the same definite proportions by mass. b) If the percent composition of two samples of pure halides (compounds only containing hydrogen and a halogen) is constant, the two halides cannot be the same compound. c) The law of definite proportions says that the ratio of the elements making up a pure compound must never vary. d) C2H4 and C3H6 have a different percent by mass composition.

a) In a pure compound, the elements are always present in the same definite proportions by mass. c) The law of definite proportions says that the ratio of the elements making up a pure compound must never vary.

The plus sign in a chemical equation is equivalent to the word ___________

and

A pressure drop in a container could be due to ............... . a an increase in temperature b a decrease in temperature c a leak in the container d a decrease of the container's volume

b a decrease in temperature c a leak in the container

When the volume of a container is increased at constant external pressure, the pressure inside the container will ............... . a increase b decrease c not change

b decrease

At constant temperature and pressure, if the volume of a gas decreases, the number of molecules must have ............... . a increased b decreased

b decreased

Boyle's law explains the process of respiration in animals. At constant temperature, the muscles in our abdomen contract, and this contraction expands the volume of our lungs. As the lung volume increases, the pressure inside the lungs ............... , and the atmospheric pressure pushes the air into our lung a increases b decreases

b decreases

The rate of evaporation of a liquid will be reduced by ............... a increasing the temperature b decreasing the temperature c increasing the surface area d decreasing the surface area e no correct answer

b decreasing the temperature d decreasing the surface area

Gay-Lussac's law indicates that the temperature and pressure of a gas are ............... proportional. a inversely b directly

b directly Gay-Lussac's law can be expressed as: P1/T1= P2/T2

Condensation is an ............... process. a endothermic b exothermic

b exothermic

Gay-Lussac's law says that if you increase the kelvin temperature of a given mass of gas at constant volume by a factor of four, the final pressure exerted by the gas will be ............... that of the original pressure. a one fourth b four

b four

In what physical state is the water as it is added to the reaction? a aqueous b liquid c solid d gaseous e more than one correct answer

b liquid

The boiling point of a liquid is the temperature at which ............... . a the vapor pressure of a liquid is greater than the external or atmospheric pressure b the vapor pressure of a liquid is equal to the external or atmospheric pressure c the external or atmospheric pressure is greater than the vapor pressure of a liquid d no correct answer

b the vapor pressure of a liquid is equal to the external or atmospheric pressure

________________ a chemical reaction gives us the correct ratio of reactants and products.

balancing

If the mercury level in the left arm of the U-tube of the manometer shown above is higher than the level in the right arm open to the atmosphere, the pressure of the vapor inside the flask is __________ atmospheric pressure

below

Intermolecular forces are interactions that occur __________ molecules

between

When a substance changes from the liquid to the vapor state by bubble formation within the liquid, the substance is ______________

boiling

How many grams of O are held in a 20.5 L container at room temperature (25 C) under a pressure of 225 atm? a 0.170 g O2 b 2250 g O2 c 6030 g O2 d 7.19 x 10^4 g O2 e no correct answer

c 6030 g O2

Most gas camping stoves use propane as fuel. Propane is a gas at room temperature and pressure. Why can you shake a propane tank and feel its contents "slosh" like a liquid? a The cooler temperature at night causes the gas to condense. b Gases and liquids behave very similarly. Gases "slosh" just like liquids. c When the tank is filled with propane gas, the tank becomes pressurized, and the propane gas compresses to the liquid state inside the container. d no correct answer

c When the tank is filled with propane gas, the tank becomes pressurized, and the propane gas compresses to the liquid state inside the container.

Which physical state is the most different from the other two? a solid b liquid c gaseous

c gaseous

Which types of energy are mentioned in the kinetic molecular theory of matter? a sound b light c kinetic d potential e nuclear

c kinetic d potential

Charles's law says that if you reduce the kelvin temperature of a given mass of gas at constant pressure to one third the original temperature (T2 = 1/3 T1), the final volume (V2) occupied by the gas will be ............... of the original volume (V1). a double b half c one third d two times e three times

c one third

If two different substances are at the same pressure and temperature, then their _________ is the factor that will determine the physical state of these substances

chemical identity

When balancing a chemical equation, only the _________ values can be altered

coefficient

The __________ is a whole number that is used to show the ____________ of reactant or product molecules required for or produced by the reaction.

coefficient number

A series of chemical reactions which use the product of one reaction as the reactant for the next are called __________ ___________

consecutive reactions

Calculate the kinetic energy (in kg m^2/s^2) of a 3000.0 lb car traveling 50.0 miles per hour. a 2.11 x 10^2 kg m^2/s^2 b 1.52 x 10 kg m^2/s^2 c 7.60 x 10 kg m^2/s^2 d 3.38 x 10 kg m^2/s^2 e 6.80 x 10 kg m^2/s^2

d 3.38 x 10 kg m^2/s^2 Convert 3000.0 lb to kg --> 1361 kg Convert 50.0 mph to m/s --> 22.3 m/s 1/2 x (1361 kg) x (22.3 m/s ^2 )= 3.38E5 kg m^2/s^2

How many grams of H and O are required to make 400.0 g of water? a 1.00 g H and 7.92 g O b 11.2 g H and 88.8 g O c 100.0 g H and 300.0 g OH d 44.8 g H and 355.2 g O e 355.2 g H and 44.8 g O

d 44.8 g H and 355.2 g O

Draw another structure of methyl alcohol and show how hydrogen bonds might form with a water molecule.

d more than one correct answer (a & c)

If you are given grams of a substance and are asked to determine the number of atoms or molecules of that substance, what value must be calculated first? a. Use Avogadro's number as conversion factor to convert from moles to molecules or atoms b. Use the inverse of Avogadro's number as conversion factor to convert from moles to molecules or atoms c. Use the molar mass as conversion factor to convert from grams to moles d. Use the inverse of the molar mass as conversion factor to convert from grams to moles.

d. Use the inverse of the molar mass as conversion factor to convert from grams to moles.

During evaporation, the temperature of the liquid .......(1)..... and the temperature of the vapor above the liquid ......(2)...... . (separate your answers by a comma)

decreases increases