Chemistry chapter test 6,7, and 9
which of the gas laws best describes the situation below: an inflated balloon shrinks when kept in a container having liquid nitrogen
charles's law
consider the reaction between Mg(s) and HCl(aq) to produce aqueous magnesium chloride and hydrogen gas. how many liters of hydrogen gas at STP will be produced when 12.15g of magnesium reacts with an excess of hydrochloric acid?
11.2L
which of the following compounds is expected to have the highest boiling point 1.CH3OCH3 2.CH3CH2CH3 3.CH3CH2OH 4.CH3Cl 5.CH3CH2CH2CH3
CH3CH2OH
hydrogen fluoride (HF liquid) exhibits stronger hydrogen bond interactions than ammonia (NH3 gas). T or F
False
calculate the ratio of the effusion rates of N2 and N2O
1.25
what is the specific heat capacity of a metal if it requires 169.6J t change the temperature of 15.0g of the metal from 25.00C to 32.00C
1.62J/gC
human body temperature is about 309K. if a person has a lung capacity of 2.1L, what volume of air at 277K must they breathe in to fill the lungs
1.88L
A physics experiment is conducted at a pressure of 15.1kPa. What is this pressure in mmHg? (101.325kPa= 760mmHg)
113mmHg
calculate the work associated with the expansion of a gas from 42.0L to 79.0L at a constant pressure of 14.0 atm
-518L atm
the mass of 1.12 liters of gas Y at STP is found to be 6.23. The molar mass of gas Y is
125g/mol
a sample of nitrous oxide, N2O, occupies 16,500mL at STP. what is the mass of the sample
32.4g
choose the correct equation for the standard enthalpy of formation of CO(g), where delta Hf for CO= -110.5kJ/mol
C(gr) + 1/2O2(g) converted CO(g) delta H= -110.5kJ
which of the following does not have a standard enthalpy of formation equal to zero at 25C and 1.0 atm?
H2O(l)
intermolecular forces are weaker than intramolecular forces. T or F
True
which of the following is indicative of the existence of strong intramolecular forces of attraction in a liquid
a very low vapor pressure
which of the following statements correctly describes the signs of q and w for the following exothermic process at P= 1 atm and T=370K? H2O(g) converted H2O(l)
q is negative and w is positive
what is responsible for capillary action, a property of liquids in which the liquid climbs up a narrow tube?
surface tension and adhesive forces
the freezing point of helium is -270C. the freezing point of xenon is -112C. both of these are in the noble gas family. which of the following statements is supported by these data
the London dispersion forces between the helium molecules are less than the London dispersion forces between the xenon molecules.
at the same temperature, lighter molecules will have a higher average root mean square velocity than heavier molecules? T or F
true
for each of the following pairs of substances, select the one expected to have the higher melting point: I H2O, H2S II HCl, NaCl III CH4, C3H8
H2O, NaCl, C3H8
a balloon contains an anesthetic mixture of cyclopropane and oxygen at 202 torr and 570 torr, respectively. what is the ratio of the number of moles of cyclopropane to moles of oxygen
0.354
the local weather forecaster reports that the current barometric pressure is 29.4in of Hg. what is the current pressure in atm?
0.983 atm
for combustion reaction of butane C4H4(g) + O2(g) converted 4CO2(g) + 2H2O(g) at 298K and 1 atm pressure. delta H= -2877kJ/mol. what will be the heat released when 6.05g of butane is combusted under these conditions
300kJ
30.0mL fo pure water at 282K is mixed with 50.0mL of pure water at 339K. what is the final temperature of the mixture?
318K
a 6.51L sample of carbon monoxide is collected at 55C and 0.816 atm. what volume will the gas occupy at 1.05 atm and 25C
4.60L
a gaseous mixture containing 1.5 mol Ar and 3.5 mol CO2 has a total pressure of 8.6atm. what is the partial pressure of CO2?
6 atm
a sample of a gas occupies a volume of 2.62L at 25C and 1.00atm. what will be the volume at 50C and 2.00atm
1.42L
a balloon has a volume of 1.80L at 24.0C. the balloon is heated to 48.0C. calculate the new volume of the balloon
1.95L
which of the following statements is true concerning ideal gases
a gas exerts pressure as a result of the collisions of the gas molecules with the walls of the container.
when a water molecule forms a hydrogen bond with another water molecule, which atoms are involved in the interaction?
a hydrogen from one molecule and an oxygen from the other molecule
steel is considered to be a
interstitial alloy
a 47.4g sample of a metal is heated to 95.2C, and then placed in a calorimeter containing 120.0g of water (c= 4.18J/gC) at 21.5C. the final temperature of the water is 24.5C. which metal was used
iron (c= 0.45J/gC)
use the kinetic molecular theory of gases to predict what would happen to a closed sample of a gas whose temperature and the volume both are increased simultaneously
its pressure would roughly remain the same
two metals of equal mass with different heat capacities are subjected to the same amount of heat. which undergoes the smallest change in temperature.
the metal with the higher heat capacity
consider the reaction: C2H5OH(l) + 3O2(g) converted 2CO2(g) + 3H2O(l) delta H= -1.37 x 10^3kJ. consider the following propositions I the reaction is endothermic II the reaction is exothermic III the enthalpy term would be different if the water formed was gaseous which of the propositions is true
II and III
which best explains the following boiling points in kelvin temperature of the noble gas family He=4K Ne=25K Ar=95K Kr=125K Xe=170K
London dispersion forces
which of the following intermolecular forces are ordered correctly from the weakest to the strongest
London dispersion, dipole dipole, hydrogen bonding, ionic
the molecules in a sample of Solid SO2 are attracted to each other by a combination of
London forces and dipole dipole interactions
at 25C the following heats of reactions are given 2ClF + O2 converted Cl2O + F2O delta H= 167.4kJ/mol 2ClF + 2O2 converted Cl2O + 3F2O delta H= 341.4kJ/mol 2F2 + O2 converted 2F2O delta H= -43.4kJ/mol at the same temperature, calculate delta H for the reaction: ClF + F2 converted ClF3
-108.7 kJ/mol
using the information below calculate delta Hf for PbO(s) PbO(s) + CO(g) converted Pb(s) + CO2(g) delta H= -131.4kJ delta Hf for CO2(g) = -393.5kJ/mol delta Hf for CO(g) = -110.5 kJ/mol
-151.6kJ/mol
calculate delta H for the reaction C4H4(g) + 2H2(g) converted C4H8(g) using the following data: delta H combustion C4H4(g) = -2341 kJ/mol delta H combustion H2(g) = -286kJ/mol delta H combustion C4H8(g) = -2755kJ/mol
-158kJ
consider the following processes 1. 3B converted 2C + D delta H= -125kJ/mol 2. 1/2A converted B delta H= 150kJ/mol 3. E + A converted D delta H= 350kJ/mol calculate delta H for B converted E + 2C
-175kJ/mol
for the complete combustion of 1.000 mole of propane gas at 298K and 1 atm pressure. delta H= -2220kj/mol. what will be the heat when 4.70g of propane is combusted under these conditions
-237kJ
the heat of formation of Fe2O2(s) is -826.0kJ/mol. calculate the heat of the reaction 4Fe(s) + 3O2(g). 2Fe2O3(s) when a 43.20g sample of iron is reacted.
-319.5kJ
for the reaction: AgI(s) + 1/2Br2(g) converted AgBr(s) + 1/2I2(s) delta H= -54.0kJ, delta Hf for AgBr= -100.4kJ/mol, delta Hf for Br2(g)= 30.9kJ/mol, the value of delta Hf for AgI(s) is
-61.8kJ/mol
a gas delivers 874.J of heat and then has 159J of work done upon it. the change in internal energy of the gas is
-715J
exactly 312.4J heat will raise the temperature of 10.0g of a metal from 25.0C to 60.0C. What is the specific heat capacity of the metal
0.893J/gC
a sample of oxygen gas has a volume of 5.82L at 27C and 800.0 torr. How many oxygen molecules does it contain? use R=62.3637L Torr mol K
1.5 x 10^23
Gaseous chlorine is held in two separate containers at identical temperature and pressure. the volume of container A is 1.30L, and it contains 6.70mol of the gas. the volume of container B is 2.02L. how many moles of the gas are in container B?
10.4 mol
what volume is occupied by 17.8g of methane at 27C and 1.95atm? use R=0.082L atm mol K
14.0L
a sample of an unknown gas takes 434 s to diffuse through a porous plug at a given temperature. at the same temperature, N2(g) takes 175 s to diffuse through the same plug. what is the molar mass of the unknown gas
172g/mol
using the following thermolecular data 2Y(s) + 6HF(g) converted 2YF3(s) + 3H2(g) delta H= -1811.0kJ/mol 2Y(s) + 6HCl(g) converted 2YCl3(s) + 3H2(g) delta H= -1446.2kJ/mol calculate delta H for the following reaction: YF3(s) + 3HCl(g) converted YCl3(s) + 3HF(g)
182.4kJ/mol
calculate deltaHrxn for this reaction. NaNO3(s) + H2SO4(l) converted NaHSO4(s) + HNO3(g) from the given values of delta Hf NaNO3(s)= -467.8kj/mol; delta Hf NaHSO4(s)= -1125.5kj/mol; delta Hf H2SO4(l)= -814.0kj/mol; delta Hf HNO3(g)= -135.1kj/mol
21.2kJ
a chunk of lead at 91.7C was added to 200.0g of water at 15.5C. the specific heat of lead is 0.129J/gC, and the specific heat of water is 4.18J/gC. when the temperature is stabilized, the temperature of the mixture was 19.4C. assuming no heat was lost to the surroundings, what was the mass of the lead added?
350g
calculate the root mean square velocity for the O2 molecules in a sample of 02 gas at 11.8C. (R=8.3145 J/K mol)
471.1 m/s
CH4(g) + 4Cl2(g) converted CCl4(g) + 4HCl(g), delta H= -434kJ based on the above reaction, what energy occurs when 1.2 moles of methane reacts
5.2 x 10^5J are released
a 9.56g piece of solid CO2 is allowed to sublime in a balloon. the final volume of the balloon is 1.00L at 302K. what is the pressure of the gas
5.38 atm
a sample of 35.1g of methane gas has a volume of 4.24L at a pressure of 2.70atm. calculate the temperature
63.8K
what will be the pressure of a sample of 48.0g of oxygen gas in a glass container of volume 5.2L at 25C? use R=0.082L atm mol K
7.05atm
the valve between a 5L tank containing a gas at 9atm and a 10L tank containing a gas at 6atm is opened. calculate the final pressure in the tanks
7atm
consider the reaction: C2H5OH(l) + 3O2(g) converted 2CO2(g) + 3H2O(l), delta H= -1.37 x 10^3kJ. when a 27.8g sample of ethyl alcohol (molar mass= 46.07g/mol) is burned, how much energy is released as heat?
8.27 x 10^2kJ
a gas absorbs 606J of heat and then has 273J of work done upon it. the change in internal energy of the gas is
879J
a chemical reaction produced 10.1cm^3 of nitrogen gas at 23C and 746mmHg. what is the volume of this gas if the temperature and pressure are changed to 0C and 760mmHg
9.14cm^3
calculate the work associated with the compression of a gas from 121.0L to 80.0L at a constant pressure of 23.4atm.
959L atm
which of the following compounds has the lowest viscosity 1.CH3(CH2)25CH3(l) 2.CCl4(l) 3.N2(g) 4.H20(l) 5.HCl(g)
N2(g)
a gas X has a diffusion rate just 1/2 of the diffusion rate of methane. which of the following X could be?
SO2
Boyle's law states that
The volume of a fixed amount of gas is inversely proportional to its pressure at constant temperature
the specific heat capacities of metals are relatively low. T or F
True
when a system performs work on the surroundings, the work is reported with a negative sign. T or F
True
For an ideal gas, which pairs of variables are inversely proportional to each other?
V and P only
given a cylinder of fixed volume filled with 1 mol of argon gas, which of the following is correct
a cylinder of identical volume if filled with 1 mole He instead of Ar would contain the same number of atoms
hydrogen bonds account for which of the following observation
for its molar mass, water has a high boiling point
which of the following is not a postulate of the kinetic molecular theory
gas particles have most of their mass concentrated in the nucleus of the atom
consider the following specific heats of metals aluminium= 0.897J/gC Magnesium= 1.02J/gC Lithium= 3.58J/gC Silver= 0.237J/gC Gold= 0.129J/gC if the same amount of heat is added to 25.0g of each of these metals. which are all at the same initial temperature, which metal will have the highest temperature
gold
the elements in group 15, the nitrogen family, form compounds with hydrogen having the boiling points listed below: SbH3 -17C, AsH3 -55C, PH3 -87C, NH3 -33C the first three compounds illustrate a trend where the boiling point decreases as the mass decreases, however ammonia does not follow the trend because of
hydrogen bonding
the bonds between hydrogen and oxygen within a water molecule can be characterized as
intramolecular forces
according to the first law thermodynamics, the energy of the universe is constant. does this mean that delta E is always equal to zero?
no, delta E does not always equal zero because it refers to the system's internal energy. which is affected by heat and work.
which of the following properties of a real gas is related to the b coefficient in the van Der Waals equation
real gases consist of molecules or atoms that have a volume
according to the postulates of the kinetic theory of gases, the average speed of the molecules of a given gas is proportional to the
square root of the absolute temperature
if 5.0kj of energy is added to a 15.5g sample of water at 10C, the water is (hint calculate the final temperature, use the sp heat capacity to be 4.184J/gC
still a liquid
in the lab, you mix two solutions and the temperature of the resulting solution decreases. which of the following is true
the chemical reaction is absorbing energy
when a non polar liquid displays a convex meniscus, which of the following explains this behavior
the cohesive forces are stronger than the adhesive forces to the glass
at a given temperature and pressure, a sample of gas A is observed to diffuse twice as fast as a sample of a different gas, B. based on this: 1. the molar mass of B is one half that of A 2. the molar mass of A is four times that of B 3. the molar mass of B is 1.414 times that of A 4. the molar mass of A is 0.707 times that of B 5. the molar mass of B is four times that of A
the molar mass of B is four times that of A
you have 0.4 g of helium gas in a rigid steel container. you add exactly 0.4g of neon gas to this container. which of the following best describes what happens? assume that the temperature is constant
the pressure in the container increases but does not exactly double
which of the following is in accordance to graham's law
the rates of effusion of gases are inversely proportional to the square roots of their molar masses
which of the following statements is correct
the system does work on the surroundings when an ideal gas expands against a constant external pressure
Dalton's law of partial pressures states that
the total pressure of a mixture of gases is the sum of the partial pressure of all of the gaseous compounds
Charles's law states that
the volume of a fixed amount of gas is directly proportional to its temperature in Kelvin at constant pressure
the measure of resistance to flow of a liquid is
viscosity
a gas absorbs 0.0J of heat and then performs 15.8J of work. the change in internal energy of the gas is
-15.8J
calculate the work for the expansion of CO2 from 1.0 to 2.2L against a pressure of 1.0 atm at constant temperature
-1.2L atm
consider three 1L flasks at STP. flask A contains NH3 gas, flask B contains NO2 gas, and flask C contains N2 gas. in which flask do the molecules have the highest average velocity
A
which substance can be described as cations bonded together by mobile electrons 1.Kr(l) 2.Ag(s) 3.S8(s) 4.HCl(l) 5.KCl(s)
Ag(s)
which gas law best describes the situation given below? a packet of chips gets fully inflated when taken to the mountain top from a valley
Boyle's law
water sits in an open beaker. assuming constant temperature and pressure, the rate of evaporation decreases as the water evaporates. T or F
False
consider three 1L flasks at STP. Flask A contains NH3 gas, flask B contains NO2 gas, and flask C contains N2 gas, which contains the largest number of molecules
all have the same number of molecules
all of the following are postulates of the kinetic-molecular theory of gases except:
at a constant temperature, each molecule has the same kinetic energy
consider the following numbered processes 1 A converted 2B H1 2 B converted C + D H2 3 E converted 2D H3 delta H for the process A converted 2C + E is
delta H1 + 2delta H2 -delta H3
you are given the following boiling point data. which one of the liquids would you expect to have the highest vapor pressure at room temperature 1. water H2O 100C 2. methanol CH3OH 64.96C 3. ethanol CH3CH2OH 78.5C 4. ethylene glycol HO-CH2-CH2-OH 198C 5. diethyl ether CH3CH2-O-CH2CH3 34.5C
diethyl ether CH3CH2-O-CH2CH3 34.5
which of the following is the major force of attraction between molecules of CCl4
dispersion forces
which of the following is the major force of attraction between molecules of CH4
dispersion forces
According to Avogadro's law
equal moles of gases occupy the same volume at constant temperature and pressure
four identical 1.0L flasks contain the gases He, Cl2, CH4, and NH3, each at 0C and 1 atm pressure. which gas has the highest density?
Cl2
on the basis of your knowledge of bonding in liquids and solids, which of the following has the lowest melting temperature 1. NaCl 2. SiO2 3. Na 4. Cu-Zn alloy 5. Cl2
Cl2
order the following in increasing rate of effusion: F2, Cl2, NO, N02, CH4
Cl2 <NO2<F2<NO<CH4
at what temperature will 2.50 moles of gas at a pressure of 1.19atm occupy 50.9L volume in an expandable container? use R=0.082L atm mol K
22.4C
the heat combustion of acetylene, C2H2(g), at 25C is -1299kj/,mol. at this temperature, deltaH, values for CO2(g) and H2O(l) are -393 and -286kj/mol, respectively. calculate deltaHf for acetylene.
227kj/mol
a gas sample is held at constant pressure. the gas occupies 3.62L of volume when the temperature is 21.6C. determine the temperature at which the volume of the gas is 3.43L
279K
you have two samples of the same gas in the same size container, with the same pressure. the gas in the first container has a Kelvin temperature four times that of the gas in the other container. the ratio of the average velocity of particles in the first container compared to that in the second is
2:1
using the following data, calculate delta Hrxn for the equation: I2(s) + Cl2(g) converted 2ICl(g) delta Hrxn= Cl2(g) converted 2Cl(g) delta H= 242.3kJ/mol I2(g) converted 2I(g) delta H= 151.0kJ/mol ICl(g) converted I(g) + Cl(g) delta H= 211.3kJ/mol I2(s) converted I2(g) delta H= 62.8kj/mol
33.5kJ/mol
the rate of effusion of an unknown gas was measured and found to be 14.3mL/min. under identical conditions, the rate of effusion of pure oxygen gas is 16.8mL/min. based on this information, the identity of the unknown gas could be:
CO2
consider the compounds CH3OH, CCl4, and CH3Br. for each compound, list the strongest intermolecular force that operates within a sample of that compound
H-bonding is the strongest intermolecular force in Ch3OH, dispersion is the strongest intermolecular force in CCl4, and dipole dipole is the strongest intermolecular force in CH3Br
C2H5OH(l) + 3O2(g) converted 2CO2(g) + 3H2O(l), delta H= -1.37 x 10^3K for the combustion of ethyl alcohol as described in the above equation, which of the following is true? I the reaction is exothermic II the enthalpy change would be different if gaseous water was produced. III the reaction is not an oxidation-reduction one. IV the products of the reaction occupy a larger volume than the reactants.
I and II
for which of the following reactions is the enthalpy change for the reaction not equal to delta Hf of the product I 2H(g) converted H2(g) II H2(g) + O2(g) converted H2O2(l) III H2O(l) + O(g) converted H2O2(l)
I and III
consider a sample of helium gas in a cylinder fitted with a piston. the piston is frictionless but has a mass of 10.0kg applying inward. which of the following processes will cause the piston to move outward? assume ideal behavior I heating the helium inside by heating the cylinder II removing some of the helium from the cylinder III turning the cylinder upside down IV increasing the pressure all around the cylinder
I only
generally the vapor pressure of a liquid is related to: I the amount of liquid II atmospheric pressure III temperature IV intermolecular forces
III and IV
