CHM 1032
Which of the following best describes the term supersaturated?
"Supersaturated" describes a solution with a solute concentration greater than its solubility value.
What is the osmotic pressure of a 0.50L solution that contains 0.15g of benzene (C6H6) at 298.15K? Use R=0.08206L atmmol K for the ideal gas constant.
0.094 ATM
156 g C12H22O11 (sucrose) is dissolved into 4.0 L of solution. What is the molar concentration of the solution?
0.11 M
22 g of barium carbonate (BaCO3) is dissolved in a 800. mL solution. What is the molarity of the resulting solution?
0.14 M
0.250 moles of NaCl is dissolved in 0.850 L of solution. What is the molar concentration?
0.294 M
In a mixture of three gases, gas A exerts a pressure of 0.25 atm, gas B exerts a pressure of 0.80 atm, and gas C exerts a pressure of 1.35 atm. What is the mole fraction of gas B?
0.33
100. grams of ammonia (NH3) is dissolved in a 8.3 L solution. What is the molarity of the resulting solution?
0.71 M
What is the name of this molecule: CH3−CH2−CH2−CH(Cl)−CH2(Cl)?
1,2-Dichloropentane
An aqueous solution at 25∘C has a hydronium ion concentration of 9.7×10−5 M. What is the hydroxide ion concentration of the solution?
1.0X10^-10M
A sample of a gas has a pressure of 1.26bar at 58.0∘C. What is the pressure of the gas at 118∘C?
1.49 bar
At a particular temperature, a sample of pure water has a hydronium concentration of 5.4×10−8 M. Which of the following might be the temperature of the sample?
10
The hydronium concentration of a solution is equal to:
10-pH
What is the temperature of a 1.59L flask containing 0.175mol of Ne at a pressure of 1.09atm?
121
What is the mass percentage of 49 g NaCl in a 290 g solution?
17
A sample of a gas has a volume of 30.0 mL at a pressure of 6.50 psi. Determine the volume of the gas in milliliters at a pressure of 11.0 psi.
17.7 mL.
What is the name of this molecule? CH3C≡CCH2CH2CH3
2-hexyne
What is the percent mass of potassium chloride in a solution made by adding 25 g of potassium chloride to 70.0 ml of water?
20
A solution is made by adding 27 g of barium chloride into 74 g of water. What is the mass percentage of this barium chloride in this solution, to the units place?
27
Which numbered carbon position is sp-hybridized? Select all that apply.
3,4
What is the name of the compound shown? CH3−CH2−CH2−CH2−C≡C−CH2−CH3
3-Octyne
What is the name of this molecule: Cl−CH2−CH2−CH(Br)−CH(CH3)2−CH2−CH3?
3-bromo-1-chloro-4,4-dimethylhexane
Determine the concentration of hydronium ions for a 25∘C solution with a pOH of 3.50.
3.2×10−11M.
Suppose that the hydroxide ion concentration of an aqueous solution at 25∘C is 2.8×10−7 M. What is the hydronium ion concentration of the solution?
3.6×10−8 M.
What is the molarity of CaCl2 when 1.92mol of CaCl2 is dissolved in water to form 515mL of solution?
3.73 M
A solution has a pH of 9.5 at 50∘C. What is the pOH of the solution given that Kw=5.48×10−14 at this temperature?
3.8
What is the hydronium ion concentration of a solution at 25∘C with a pOH of 4.70?
5.0X10^-10M
A solution is made by adding 24.7 g of acetylcholine to 429 g of water. What is the mass percentage of acetylcholine in this solution?
5.44
What would be the molarity of a solution made from 86.5 g Ca(OH)2in 200.0 ml of water?
5.84 M
A sample of a gas has a pressure of 248mm Hg when the volume is 1.05L. What is the pressure of the gas when the volume is 3.98L?
65.4
A solution of KOH contains 15.0g of KOH in 185.0g water. What is the mass percent of KOH in the solution?
7.50
What is the pH of a solution with a pOH of 6.2?
7.8
A 10.0 L sample of xenon gas expands until it reaches 13.5 L and 550. torr. What was the initial pressure of the system in torr
743 torr
According to the Bronsted-Lowry definition, what acts as the acid when the reaction below proceeds in the forward direction? CN−+H2O⇌OH−+HCN
A Bronsted-Lowry acid is a compound that donates a proton. In this case, the compound acting as the acid is H2O.
According to the Bronsted-Lowry definition, what acts as the acid when the reaction below proceeds in the forward direction? H2O+HF⇌F−+H3O+
A Bronsted-Lowry acid is a compound that donates a proton. In this case, the compound acting as the acid is HF.
According to the Bronsted-Lowry definition, what acts as the acid when the reaction below proceeds in the forward direction? H2O+HSO−4⇌SO2−4+H3O+
A Bronsted-Lowry acid is a compound that donates a proton. In this case, the compound acting as the acid is HSO−4.
When the reaction below is going in the forward direction, which compound acts as the base, according to the Bronsted-Lowry definition? PH+4+H2O↽−−⇀PH3+H3O+
A Bronsted-Lowry base is the species that accepts a proton in an acid-base reaction. In this case, the compound acting as the base when the reaction is going from left to right is H2O
According to the Bronsted-Lowry definition, what is the conjugate base when the reaction below proceeds in the forward direction? H2PO−4+H2O⇌H3O++HPO2−4
A Bronsted-Lowry conjugate base is the remaining portion of an acidic compound that has just donated a proton. In this case, the compound acting as the conjugate base is HPO2−4.
Which of the following terms best describes a solution having a relatively high concentration of solute?
A concentrated solution has a relatively high concentration of solute.
A functional group attached to a carbon chain is called a
A functional group that branches off from the main carbon chain is called a substituent.
Unsaturated
A solution containing less than the maximum amount of solute that will dissolve in the solvent: a solution with a concentration below the solubility limit. Additional solute will dissolve in an unsaturated solution.
Supersaturated
A solution containing more than the maximum amount of solute that can be dissolved in the solvent at equilibrium: a solution with a concentration above the solubility limit. Additional solute will not dissolve in a supersaturated solution; rather, it will cause dissolved solute to precipitate from the solution. This can occur by adding a seed crystal or by introducing some mechanical disturbance to the solution
According to Boyle's law, as volume increases pressure _______
According to Boyle's law, as volume increases pressure decreases. The volume of a given amount of gas held at constant temperature is inversely proportional to its pressure. This can be seen in P1V1=P2V2.
According to Charles's law, as volume increases, temperature ________
According to Charles's law, the volume and temperature of a gas (in degrees Kelvin) are directly proportional. If one decreases, the other one will decrease as well (and the same for increase).
Carbon atoms in alkynes can contain which of the following bond angles? Select all that apply.
Alkynes contain carbon atoms involved at least one triple bond, which have a bond angle of 180∘. Alkynes may also contain carbons involved in single bonds (with bond angles of 109.5∘) or double bonds (with bond angles of 120∘).
As temperature increases, Kw will:
As temperature increases, there will be more hydronium and hydroxide ions in solution, so Kw will increase.
Which is a correct way of stating Boyle's law?
Boyle's law states that the volume and pressure of a gas vary inversely if the gas is held at a constant temperature. In other words, if the volume is increased by a certain factor, the pressure will decrease by same factor.
What are the causes of respiratory acidosis?
Breathing difficulty or lung problems reduce the ability to remove CO2, resulting in a CO2 pressure above 42 torr. Acidic protons are not removed and the pH drops.
A solution of a compound in water conducts electricity, turns litmus red, and has a sour taste. What compound might be in the solution?
C3H5(COOH)3
An example of an alkene is:
CH2=CHCH=CH2 is an alkene.
Which is a possible example of species that can comprise a buffer solution?
CH3COOH and NaCH3COO
Which of the following is a base ionization reaction?
CN−+H2O↽−−⇀OH−+HCN
The simplest organic compounds contain only two elements. What are they?
Carbon and hydrogen
Which acid is responsible for maintaining the pH of the blood stream?
Carbonic acid, or H2CO3, and its conjugate base comprise the buffer solution in the bloodstream.
What are the causes of metabolic acidosis?
Changes in the H+ or HCO−3 concentrations that cannot be adequately relieved by the body result in the pH dropping. It can be brought on by diabetes, kidney disease, diarrhea or vomiting, or inadequate oxygen.
Which of the following states that the volume of a given amount of gas is directly proportional to its temperature (using the Kelvin scale) when the pressure is held constant?
Charles's law states that the volume of a given amount of gas is directly proportional to its temperature on the Kelvin scale when pressure is constant. This can be seen in V1T1=V2T2. If the temperature of a gas were to increase, the volume would increase. If the temperature of a gas were to decrease, the volume would decrease.
Citric acid is found in __________.
Citric acid is a component of fruits, used in certain cleaning products, and is an intermediate product in carbohydrate digestion.
In the equation C1V1=C2V2, what does C represent?
Concentration
What type of alkane does not follow the CnH2n+2 formula?
Cyclic alkanes have the formula CnH2n, while all other alkanes follow the formula CnH2n+2.
The molecular formula C5H10 can refer to which of the following molecules?
Cyclopentane 1-pentene 2-pentene
Which of the following would be included in the name of an alkane with 2 chlorine atoms as substituents?
Dichloro
Which of the following is a characteristic of alkanes?
Each of their carbon atoms is bonded to four other atoms.
Of the following, which are characteristics of basic solutions? (Select all that apply)
Greater concentration of hydroxide ions than hydronium ions [H3O+]<[OH−]
Which is a possible example of species that can comprise a buffer solution?
H2PO-4 AND H3PO4
What is the formula for the conjugate acid of dihydrogen phosphate, H2PO−4?
H3PO4
Most acids are safely stored in glass bottles because glass does not interact with most acids. One particular acid is stored in plastic bottles because it is capable of etching glass. Give the molecular formula of this acid.
Hydrofluoric acid, or HF, cannot be stored in glassware like most acids because it can dissolve glass.
How are hydrogen atoms represented in an alkane skeletal structure?
Hydrogen atoms are not drawn
Water will flow from the cells into the solution and the cells may shrivel. Which of the following types of tonicity best describes this toxic effect?
Hyper means "greater than." There is a greater concentration of solute in the solution than in the red blood cells. Water will flow from the cells into the solution and the cells may shrivel (crenation).hypertonic
Identify the structure with the name 4-chlorotoluene
IMAGE
If an electrolyte generates ions in solution with 100% efficiency, that substance would be considered a:
If a substance is a strong electrolyte, it will completely dissociate or react, generating as many ions as possible.
If two methyl groups on carbons connected by a double bond are on opposite sides of the double bond, which isomer is it?
If the methyl groups are on opposite sides of the double bond, this must be the trans isomer.
An aqueous acid ionization reaction always generates
In an acid ionization reaction, an acid will donate a proton to a water molecule to generate hydronium.
Which of the following statements is NOT true about inorganic compounds versus organic compounds?
Inorganic compounds are generally more flammable than organic compounds.
How does the concentration of dissolved CO2 in the soda beverage change when the bottle is opened?
It decreases.
Which of the following will increase the solubility of carbon dioxide in seltzer water?
Keeping it in the refrigerator.
Choose the options below that are not characteristics of alkanes.
Linear alkanes have the molecular formula CnH2n. They have delocalized alternating carbon-carbon single and double bonds.
Which is a possible example of species that can comprise a buffer solution?
NH3 and NH4Cl Ammonia and ammonium chloride are the only example of a weak base paired with its conjugate acid.
Which of the following is NOT true about selective permeation?
NONE OF THE ABOVE Biological cell membranes provide elegant examples of selective permeation in nature, while dialysis tubing used to remove metabolic wastes from blood is a more simplistic technological example. Regardless of how they may be fabricated, these materials are generally referred to as semipermeable membranes.
Suppose a solution is described as concentrated. Which of the following statements can be concluded?
None of the above
Which of the following molecules is an alkene?
None of the above
If an external stimulus is acting to increase the pH of blood (making the blood more alkaline), what chemical or ion is being generated in the bloodstream and needs to be neutralized?
OH-
Which would conduct electricity best?
Ocean water is saline, it has lots of ions, as opposed to tap water which has some ions, and purified water, which has essentially none. So ocean water would be the best conductor of electricity.
On the Kelvin scale, 0 is known as __________.
On the Kelvin scale, 0 is known as absolute zero. All gas law calculations require that temperatures be on the Kelvin scale. Absolute zero implies that the kinetic energy of all molecules is zero as well.
What is true about selective permeation?
Only molecules or ions of a certain size, shape, polarity, charge, and so forth, are capable of passing through the material.
A balloon has 1.00 L gas at sea level (1.00 atm). If the balloon is taken to a point with air pressure of 0.850 atm, what will the new volume be in liters?
P1V1=P2V2 V2=(1.00 atm)(1.00 L)0.850 atm=1.1765 L The answer should have three significant figures, so round to 1.18 L.
A mixture with H2 and He exerts a total pressure of 0.48 atm. If there is 1.0 g of H2 and 1.0 g of He in the mixture, what is the partial pressure of the helium gas?
PHe=XHe×Ptotal=nHenHe+nH2×Ptotal=(0.24981mol0.24981mol+0.49603mol)×(0.48atm)=0.33494×0.48atm=0.161atm
A container with 3.00 moles of gas has a volume of 60.0 L. With a temperature at 400.K, what is the pressure in atm?
PV=nRT, P=nRTV=(3.00 mol)(0.08206L atmmol K)(400. K)(60.0 L)=1.6412 atm
Ethylene is a basic raw material used to make which of the following? (select all that apply)
Plastics, polymers, and petrochemicals
When considering solutions of liquids in liquids, polar liquids are generally miscible with
Polar liquids are generally miscible with other polar liquids, as predicted by the "like dissolves like" axiom.
Which of the following are characteristics of strong electrolytes? (select all that apply)
Strong electrolytes exhibit high conductivity and produce a high concentration of ions when dissolved in water.
At what temperature in K will 4.00 moles of gas occupy a volume of 12.0 L at a pressure of 5.60 atm?
T=PVnR=(5.60 atm)(12.0 L)(4.00 mol)(0.08206L atmmol K)=204.73K The answer should have three significant figures, so round to 205 K.
Which of the following is a true statement about the Lewis definition of acids and bases?
The Lewis definition of acids and bases is based on donating or accepting an electron pair.
Which of the following stays constant when diluting a solution?
The amount of solute in a solution is unaffected by dilution. The addition of solvent to a solution will change the solution concentration (in molarity and in all other units) and the solution volume, but the moles of solute remains constant.
When bases are introduced into the blood, the concentration of OH− is increased. The bicarbonate buffer system acts to neutralize this increase through the reaction show below. What is the missing product? OH−+H2CO3⇌H2O+________
The bicarbonate buffer system neutralizes bases by reacting carbonic acid with hydroxide ions to form water and bicarbonate ions, HCO−3.
What are the causes of metabolic alkalosis?
The body eliminates too much acid or produces too much base for the renal system to compensate, resulting in a rise in blood pH.
Which of the following is not present in skeletal structures?
The chemical symbol for carbon The chemical symbol for hydrogen
The image above is a solution of two different liquids. Which of the following best describes this solution?
The liquids are immiscible. The liquids have low mutual solubility.
inorganic compounds
The melting point of inorganic compounds is generally higher than that of organic compounds because of strong ionic bonding.
Identify the correct statements regarding the melting points of iron sulfide and methanol.
The melting point of iron sulfide is high and the melting point of methanol is low.
When a solution is saturated and additional solute sits at the bottom of the vessel
The solute will continue to dissolve and precipitate at precisely the same rate so that the concentration will remain fixed.
If red blood cells are put in a 0.7%mv sodium chloride solution, what will happen?
The solution is hypotonic. Water will flow from the solution into the cells, and the cells may burst (hemolysis).
Classify the tonicity of a solution made by dissolving 9.0g of sodium chloride in 1.0L of water. Choose the correct answer and explanation below.
The solution is isotonic because it has a 0.9%m/v concentration of sodium chloride.
Name the aromatic compound with the structure below.
The structure contains a benzene ring with a single substituent group. There is an −OH group, so it is named phenol.
The following shows the buffering reactions that regulate the pH of blood: H++HCO−3⇌H2CO3⇌H2O+CO2. What actions of the system will lower the pH?
The system can shift to the left by breathing more slowly so that less carbon dioxide (CO2) is exhaled.
Identify the correct statement about types of bonds that form in inorganic compounds.
They are more often ionic bonds.
Which of the following are true of alkenes? (Select all that apply)
They contain at least one sp2 hybrid orbital. They are unsaturated hydrocarbons. The bond angles in some of their carbon chains are 120∘.
Identify the options below that are not characteristics of alkynes.
They contain only single bonds. They contain only one π bond.
Of the following, which is a characteristic of nonelectrolytes?
They produce no ions when dissolved in water.
immiscible
Two liquids that do not mix to an appreciable extent
What is the volume of a sample of ethane at 467 K and 1.1 atm if it occupies 405 mL at 298 K and 1.1 atm?
V2=(405 mL)(467 K)298 KV2=634.68 mL
A 2.0 L balloon full of air is at 25.00∘C. What will be the volume of the balloon if it is placed in the freezer at −4.00∘C
V2=V1T2T1=2.0 L×269.15K298.15K=1.805 L
Which of the following is true of water in a base ionization reaction?
Water loses a proton and is acting as an acid.
When doing calculations with temperature using Charles's law, the correct scale to use will be __________.
We always use the Kelvin scale when doing calculations for gases.
Of the following, which are generally weak electrolytes?
Weak acids and weak bases are generally weak electrolytes.
What is the normal pH inside cells?
What is the normal pH inside cells?
If an external stimulus is acting to make the blood more acidic, what chemical or ion is being generated in the bloodstream and needs to be neutralized?
When a solution becomes more acidic, this corresponds to an increase in hydrogen (hydronium) ions, H+ or H3O+.
In dilution, which of the following is added to a solution?
When we dilute a solution, we add additional solvent.
Identify the inorganic compounds.a. iron oxide(Fe2O3)b. water (H2O)c. methane (CH4)
a. iron oxide(Fe2O3)b. water (H2O) Water and iron oxide do not have carbon. Methane does.
In a buffer solution made of acetic acid and sodium acetate, if a small amount of acid is added, the added acid will react with which of the following?
acetate ions
Which of the following shows the correct order of the components in the equation below? HF+H2O↽−−⇀H3O++F−
acid + base ↽−−⇀ acid + base
Which of the following will decrease the concentration of a solution? Select all that apply.
adding more solvent removing moles of solute
Which of the following will exhibit the greatest change in pH when 1.0 mL of 1M HCl is added to it?
an unbuffered aqueous solution
When numbering the parent chain for an alkane with only alkyl or halogen substituents, we will number so as to give:
any substituent occurring soonest
Organic compounds
are generally more flammable.
Which of the following is the term for the reaction between two molecules of the same neutral substance to produce an ion pair?
autoionization
In organic compounds
both the melting point and boiling point are low
An electrolyte will yield ions by undergoing a:
depends on the substance
Pressure and temperature of an ideal gas are __________.
directly proportional As temperature increases or decreases, the pressure will increase or decrease accordingly, if the volume is kept constant.
In a model that precedes the Bronsted-Lowry model, a base is defined as something that ________
dissolves in water to yield hydroxide ions
According to Boyle's Law, if the pressure in a container filled with air is quadrupled, we know that the volume must be __________
divided by four
Kinetic molecular theory applies to __________.
gases: Kinetic molecular theory specifically applies to gas molecules/atoms.
Inorganic compounds
generally have higher melting and boiling points than organic compounds.
Reverse osmosis requires an external pressure that is __________ osmotic pressure.
greater than
Which of the following might result in damaged red blood cells?
hemolysis and crenation Red blood cell membranes are water permeable and will swell and possibly rupture in a hypotonic solution, which is called hemolysis. They maintain normal volume and shape in an isotonic solution. They shrivel and possibly die in a hypertonic solution, which is called crenation.
An aqueous base ionization reaction always generates
hydroxide In a base ionization reaction, a base will accept a proton from water to generate hydroxide.
In a __________ solution, water will flow from the solution into the cells and the cells may burst
hypotonic
Ashley is making a solution of sugar (C12H22O11) in water. She adds 180 g of sugar to 100 g of water at 10∘C and stirs the solution for a couple of seconds to help it dissolve. She adds 40 more grams of sugar to the solution and realizes that this additional sugar is not dissolving. What can she do to dissolve the additional 40 g of sugar?
increase the temperature to 30∘C
What is the term used to describe the equilibrium constant for the autoionization of water?
ion-product constant.
liquid
is a fluid that conforms to the shape of its container but that retains a nearly constant volume independent of pressure. The volume is definite (does not change) if the temperature and pressure are constant. When a solid is heated above its melting point, it becomes liquid because the pressure is higher than the triple point of the substance.
A buffer
is a solution that is resistant to pH changes because it is made up of a weak acid and its conjugate base (or equivalently, a weak base and its conjugate acid). Acetic acid and sodium acetate are the only example of a weak acid paired with its conjugate base.
Iron sulfide
is an inorganic compound
Methanol
is an inorganic compound
Potential energy
is energy due to relative position, composition, or condition.
Energy
is the capacity to do work (applying a force to move matter).
Kinetic energy (KE)
is the energy of motion.
A solution that a patient needs for medical treatment needs to be __________ with blood cells.
isotonic
If there is an equal flow of water in and out of the cells, the type of tonicity is said to be __________.
isotonic Iso means "the same." In an isotonic solution, the concentration of solute in the solution is roughly the same as in the cells. There is an equal flow of water in and out of the cells.
Ideal gas behavior is reasonable for gases that exhibit:
low pressure high temperature
The osmotic pressure of a dilute solution depends on which of the following?
molarity the gas constant temperature
Non-polar solutes are soluble in which of the following?
non-polar solvents
Which substances are immiscible?
oil and water Oil is non-polar and water is polar, so these will be immiscible.
Which sample of gas would exert the greatest pressure, assuming that the volume of each sample is the same?
one mole of CO2 at 330 K The identity of the gas is irrelevant. If they all are present in the same molar quantity ( 1mole) and at the same volume, the gas at the greatest temperature will exert the greatest pressure.
What will be the pH of a solution with a hydronium concentration of 5.6×10−6 M?
pH=−log[H3O+]pH=−log(5.6×10−6)pH=5.25
Identify the option below that is a characteristic of acidic solutions.
pOH levels greater than 7 at 25∘C
What is the name of KHCO3?
potassium bicarbonate
A patient has symptoms including increased breathing rate, numbness, muscle spasms, and nausea. The blood pH is checked and found to be 7.5 and CO2 pressure is 37 torr. The patient most likely has what condition?
respiratory alkalosis
Which of the following techniques is used for large-scale desalination of seawater and on smaller scales to produce high-purity tap water for drinking?
reverse osmosis
Solubility is determined by:
solute-solute forces solvent-solvent forces solute-solvent forces
When diluting a solution, which of the following changes?
solution volume solution concentration volume of solvent
In the process of dilution the amount of ________ increases and the amount of ______ stays the sam
solvent, solute
If a supersaturated solution is introduced to a mechanical disturbance or a seed crystal, what will happen?
some solute will precipitate
In an alkyne, the carbons participating in a triple bond will have what hybridization?
sp
A saturated solution contains more solute than it can accommodate, and is heated until all of the excess solute just barely dissolved. It is then cooled rapidly, such that the solute remains dissolved. The solution is then referred to as which of the following?
supersaturated
Which fragment would be listed first when naming a molecule?
tetrachloro
For an experiment, you are required to prepare a series of three solutions by diluting a cobalt(II) chloride stock solution. After making each solution, you notice that each is a different shade of pink. Which is the most concentrated?
the stock solution
Gay-Lussac's law assumes that __________. (Select all the are true.)
the volume is held constant the number of moles is held constant
solid
· particles are packed closely together. The forces between the particles are strong enough that the particles cannot move freely; they can only vibrate. As a result, a solid has a stable, definite shape and a definite volume. Solids can only change shape under force, as when broken or cut.
Saturated
A solution containing the maximum amount of a solute dissolved in the solvent: a solution at the solubility limit. Additional solute will not dissolve in a saturated solution.
The ideal gas law displays the relationship in which of the following?
Amontons's law Charles's law Boyle's law Avogadro's law
Which of the following states that the pressure of a given amount of gas is directly proportional to its temperature on the Kelvin scale when the volume is held constant?
Amontons's or Gay-Lussac's law
A benzene ring with an amino group as a substituent is called which of the following?
Aniline is the name given to a benzene ring with an amino group as a substituent.
Which of the following is likely to happen when a glass of cold water is warmed to room temperature?
As the temperature rises, the solubility of air in water decreases, resulting in the formation of small air bubbles in the water.
According to KMT, at constant pressure and temperature, the frequency and force of molecule wall collisions are constant. So increasing the number of gaseous molecules will require a proportional increase in the container volume in order to yield a decrease in the number of collisions per unit area to make up for the increased frequency of collisions. What gas law is KMT explaining?
Avogadro's law
Alison observes that when she injects additional gas molecules into a container of gas, the number of collisions in the container (and the pressure inside) increases. She then increases the volume of the container just enough to restore it to its original pressure. Which of the following laws best describes what Alison observed?
Avogadro's law states that increasing the number of gaseous molecules will require a proportional increase in the container volume in order to maintain a constant pressure and temperature.
A mixture with H2 and He exerts a total pressure of 0.48 atm. If there is 1.0 g of H2 and 1.0 g of He in the mixture, what is the partial pressure (in atmospheres) of hydrogen?
First convert the mass of H2 to moles using the molar mass. (1 gram H2⋅1 mol H22.016 g H2)≈0.50molH2 Next, convert the mass of helium He to moles using the atomic mass. (1 gram He⋅1 mol He4.003 g He)≈0.25mol He The total number of moles is about 0.75 moles . The partial pressure of a component of a gas mixture can be found by multiplying the mole fraction by the total pressure. PH2=XH2×PtotalPH2=(0.50 mol0.75 mol)(0.48 atm)=0.32 atm
Which of the following can be explained by the kinetic molecular theory (KMT)? Select all that apply.
Increasing rates of collisions of gas particles with their container as temperature increases translates to a higher pressure within that container. Lowering the temperature of gas molecules decreases their average kinetic energy. Increasingly energetic collisions between gas particles and walls of the chamber lead to increasing pressure with increasing temperature.
Which of the following statements agrees with the chemical axiom "like dissolves like"?
Polar solutes dissolve in polar solvents. Non-polar solutes dissolve in non-polar solvents.
According to the kinetic molecular theory, where does the pressure exerted by a gas in a container come from?
Pressure results from collisions between the constantly moving gas molecules and the container walls.
Which of the following statements are true about organic compounds versus inorganic compounds?
The melting points of organic compounds are usually lower than those of inorganic compounds. The boiling points of organic compounds are usually lower than those of inorganic compounds.
Which of the following provides the most descriptive picture of an alkane?
The skeletal structure of an alkane shows the connectivity of all of the carbons it contains, and best reflects the geometry of the molecule in two dimensions. The hydrogens attached to each carbon are implied, not drawn. However, there is no ambiguity in the number or placement of the hydrogens, as these can be filled in logically based on the fact that each carbon must have an octet.
Which is a correct way of stating Charles's law?
V=kT VT=k V1T1=V2T2 all of the above
1.00mol of oxygen gas has a pressure of 2.50atm at 325K. Use the ideal gas law to determine the volume of the gas. Use R=0.08206 L atmmol K for the ideal gas constant.
VVV=nRTP=(1mol)(0.08206 L atmmol K)(325K)(2.50atm)=10.67L
According to kinetic molecular theory, if the volume of a gas increases, in order to maintain constant pressure, the temperature must __________.
increase: If the volume increases, the only way for the particles to continue hitting the sides with the same frequency is to move faster, so they travel a greater distance in the same amount of time, thus the temperature must increase.
A supersaturated solution of a particular ionic solid is prepared. If a seed crystal of the solute is added to the supersaturated solution, it will lead to ______.
precipitation Seed crystals allow solute particles in the supersaturated solution to join a crystal lattice and, thus, precipitate out of solution, sometimes very rapidly.
According to kinetic molecular theory, the force a gas exerts on its container by virtue of elastic collisions is the __________.
pressure: This is the definition of the pressure of a gas, according to kinetic molecular theory.
A student is making chocolate milk and mixes the chocolate powder (solute) into the milk (solvent) until no more powder can be dissolved. The mixture described is
saturated
The ideal gas law makes which of the following assumptions
the gas particles are constantly in random motion and have no volume particles do not interact
Gas
· molecules have either very weak bonds or no bonds at all, so they can move freely and quickly. Because of this, not only will a gas conform to the shape of its container, it will also expand to completely fill the container. Gas molecules have enough kinetic energy that the effect of intermolecular forces is small (or zero, for an ideal gas), and they are spaced very far apart from each other; the typical distance between neighboring molecules is much greater than the size of the molecules themselves.