Chem 1301 Exam IV
A 8.96-g piece of solid CO2 is allowed to sublime in a balloon.
4.91 atm
The ΔH value for the reaction _______ is -90.8 kJ. How much heat is released when 97.5 g Hg is reacted with oxygen?
44.1 kJ
Below is a phase diagram for compound Y. The normal boiling point of Y is most likely
47 C
Calculate the root mean square velocity for the O2 molecules in a sample of O2 gas at 14.5 C.
473.4 m/s
Calculate the ratio of the effusion rates of N2 to N2O
1.25
What is the specific heat capacity of a metal if it requires 177.5 J
1.31 J/gC
A crystal was analyzed with x rays having 1.50 Å wavelength.
1.82 Å
Calculate ΔH for the following reaction
101.9 kJ/mol
Gaseous chlorine is held in two separate containers at identical temperature and pressure. The volume of container 1 is 1.30 L, and it contains 6.70 mol of the gas. The volume of container 2 is 2.26 L. How many moles of the gas are in container 2?
11.6 mol
When a 0.299 mol of a weak base is reacted with excess HCl
-23.1 kJ
A gas absorbs 0.0 J of heat and then performs 30.8 J of work. The change in internal energy of the gas is
-30.8 J
Calculate the work for the expansion of CO2 from 1.0 to 5.2 liters against a pressure of 1.0 atm at constant temperature.
-4.2 L•atm
A 140 g sample of water at 25 C is mixed with 112.8 g of a certain metal at 100 C. After thermal equilibrium
0.34 J/ gC
A glass column is filled with mercury and inverted in a pool of mercury. The mercury column stabilizes at night at a height of 758 mm above the pool of mercury.
0.997 atm
A sample of helium gas occupies 19.1 L at 23 C and 0.956 atm
16.1 L
How much heat is required to raise the temp of a 6.69 g sample of iron from 25 C to 79.8 C?
165 J
For an ideal gas, which pairs of variables are inversely proportional to each other
2 only
An automobile tire is filled with air at a pressure of 29.1 lb/in^2 at 25C.
27.1 lb/in^2
When one mole of benzene is vaporized at a constant pressure of 1.00 atm and at its boiling point of 353.0 K, 30.40 kJ of energy is absorbed and the volume change is +28.90 L
27.47 kJ
A 4.26-L sample of carbon monoxide is collected at 55C and 0.907 atm. What volume will the gas occupy at 1.05 atm and 25C?
3.34 L
When one mole of benzene is vaporized at a constant pressure of 1.00 atm and at its boiling point of 353 K, 30.73 kJ of energy is absorbed and the volume is changed to +28.90 L
30.73
30 mL of pure water at 282 K is mixed with 50.0 mL of pure water at 345 K. Final temp?
321K
The heat of combustion of benzene
33.9 kJ/C
When a 19.2 g sample of ethyl alcohol is burned, how much energy is released as heat?
5.71 x 10^2 kJ
Which of the following would have a higher rate of effusion than C2H2?
CH4
Which of the following is paired incorrectly?
Gold metal- simple cubic unit cell
For the combustion of ethyl alcohol as described in the above equation, which of the following is true?
I, II
Which of the following would you expect to have the highest boiling point?
I2
The bonds between hydrogen and oxygen within a water molecule can be characterized as
Intramolecular forces
Order the intermolecular forces from weakest to strongest
London dispersion, dipole-dipole, hydrogen bonding, ionic
Which of the compounds below is not an example of a molecular solid?
SiO2 (s)
Generally the vapor pressure of a liquid is related to:
Temperature and Intermolecular Forces
A liquid placed in a closed container will evaporate until equilibrium is reached.
The boundary (meniscus) between liquid and vapor disappears
Which of these statements is false?
The size of the unit cell of Li and Cs is the same
A state function does not depend on the systems past or future
True
In exothermic reactions, potential energy stored in chemical bonds is being converted to thermal energy via heat
True
Liquids with large intermolecular forces tend to have high surface tension.
True
Table salt and table sugar are both crystalline solids
True
The specific heat capacities of metals are relatively low
True
When a system performs work on their surroundings, the work is reported with a negative sign
True
Which conditions of P, T, and n, respectively, are most ideal?
low P, high T, low n
Which of the following statements correctly describes the signs of q and w for the following exothermic processes at P=1 atm and T=370 K?
q is negative, w is positive
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
For a particular process q = 20kJ and w= 15 kJ. Which of the following statements is true?
ΔE= 35 kJ
For a particular process, q=20 kJ and w=15kJ. Which of the following statements is true?
ΔE= 35 kJ
The vapor pressure of water at 100.0 C is
760 torr
At 25C the following heats of reaction are known. At the same temp, calculate ΔH for the reaction
-108.7 kJ/ mol
Consider a sample of gas in a container on a comfortable spring day.
6.4 atm
Given the graph, what is the boiling point of chloroform at standard pressure?
60 C
What is the kinetic energy of a 2.77 kg object moving at 85.5 km/ hr?
7.81 x 10^2 kJ
Consider three 1-L flasks at STP. Flask A contains NH3 gas, flask B contains NO2 gas, and flask C contains N2 gas.
All are the same
Consider the following specific years of metals. If the same amount of heat is added to 25 g of each of the metals, which are all the same initial temp, which metal will have the highest temp?
Bismuth
Pressure is
Defined as the force per unit area exerted by an object
Methane exhibits stronger bonding than
False
Which of these statements is incorrect?
Molecular solids have high melting points
Which substance involves no bonding forces except london dispersion forces?
N2 (s)
Which of the following is most likely to be a solid at room temp?
Na2S
The SI unit of pressure
Pascal