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