Lv 2408 points

# Annie

• ### Calculate the freezing point and boiling point.?

need some help with these problems..

Calculate the freezing point and boiling point of each of the following solutions.

19.3 g of decane, C10H22, in 47.7 g CHCl3

CHCL3:

Normal boiling point 61.2

Kb 3.63

Normal freezing point -63.5

Kf 4.68

0.40 mol ethylene gycol and 0.14 mol KBr in 160 g H2O

H2O:

Normal boiling point - 100.0

Kb - 0.51

Normal freezing point - 0.0

Kf - 1.86

• ### Help Calculating Molarity with solutions?

Calculate the molarity of the following aqueous solutions.

(a) 0.508 g Mg(NO3)2 in 160.0 mL of solution

(b) 21.6 g LiClO4 · 3 H2O in 210. mL of solution

(c) 50.0 mL of 3.76 M HNO3 diluted to 0.230 L

• ### Help with comparative dispersion forces?

Which member in each pair has the larger dispersion forces?

Part A)

CCl4 or CH4

Part B)

PCl3 or PCl5

Part C)

Br2 or HBr

• ### Help with gas law word problem?

In an experiment reported in the scientific literature, male cockroaches were made to run at different speeds on a miniature treadmill while their oxygen consumption was measured. In one hour the average cockroach running at 0.08 km/hr consumed 0.80 mL of O2 at 1 atm pressure and 24°C per gram of insect mass.

(a) How many moles of O2 would be consumed in 1 hr by a 5.1-g cockroach moving at this speed?

(b) This same cockroach is caught by a child and placed in a 0.25-gal fruit jar with a tight lid. Assuming the same level of continuous activity as in the research, what percentage of the available O2 will the cockroach consume in a 48-hr period? (Air is 21 mol percent O2.) (answer as a %)

• ### Density of gas question?!?

(a) Calculate the density of NO2 gas at 0.979 atm and 44°C.

(in g/L)

(b) Calculate the molar mass of a gas if 2.80 g occupies 0.869 L at 697 torr and 42°C.

(in g/mol)

• ### Pressure problem with gases?!?

I have worked on this for a while and can't figure out what to do!!

A mixture containing 0.718 mol He(g), 0.317 mol Ne(g), and 0.150 mol Ar(g) is confined in a 15.00-L vessel at 30.°C. (See this table of fundamental constants.)

(a) Calculate the partial pressure of each of the gases in the mixture.

(b) Calculate the total pressure of the mixture.

• ### Gas law volume vs. pressure help?!? (10 points best answer)?

An aerosol spray can with a volume of 350. mL contains 2.28 g of propane gas (C3H8) as a propellant.

(a) If the can is at 34°C, what is the pressure in the can? (in atm)

(b) What volume would the propane occupy at STP? (in L)

(c) The can's label says that exposure to temperatures above 130.°F may cause the can to burst. What is the pressure in the can at this temperature? (in atm)

• ### Pressure/ Temperature/ volume questions?!?!?

A)Calculate the number of molecules in a deep breath of air whose volume is 2.41 L at body temperature, 37°C, and a pressure of 744 torr.

B) The adult blue whale has a lung capacity of 5.0 103 L. Calculate the mass of air (assume an average molar mass 28.98 g/mol) contained in an adult blue whale's lungs at 0.0°C and 1.00 atm, assuming the air behaves ideally. (answer in kg)

• ### Temperature/Pressure/ volume help!!?

Room temperature is often assumed to be 25°C. Calculate the molar volume of an ideal gas at 25°C and 1 atm pressure

• ### Temperature/pressure gas law problem help!!!?

Hydrogen and iodine gases react to form hydrogen iodide gas as follows:

H2(g) + I2(g) → 2 HI(g)

At a certain temperature and pressure, 2.8 L of H2 reacts with 2.8 L of I2. If all the H2 and I2 are consumed, what volume of HI, at the same temperature and pressure, will be produced?

• ### Gas laws homogenous mixture and gas vs. solid help!!!?

1 A liquid and a gas are moved to larger containers. How does their behavior differ once they are in the larger containers? Explain the difference in molecular terms.

a. Gases do not expand because of already large intermolecular distances, and liquids can not expand because of large intermolecular forces.

b. Both liquids and gases can only expand till a certain limit (limited by the intermolecular distances and intermolecular forces).

c. The gas molecules expand to double their initial volume, and liquids expand to 1.2 times their initial volume.

d. Gas molecules have large intermolecular distances and they are in constant motion, so the gas expands to fill the entire volume. Intermolecular attractive forces do not allow the volume of liquids to change.

2. Although liquid water and carbon tetrachloride, CCl4(l), do not mix, their vapors form a homogeneous mixture. Explain.

3 Gas densities are generally reported in grams per liter, whereas liquid densities are reported in grams per milliliter. Explain the molecular basis for this difference.

• ### Help with Gas laws!!!!?

How does a gas compare with a liquid for each of the following properties?

1 density

a. A gas is less dense than a liquid because intermolecular distances of gas molecules are less than

those of liquids.

b. A gas is more dense than a liquid for a given mass.

c. A gas is less dense than a liquid because intermolecular forces are stronger in gases.

d. A gas is less dense than a liquid because most of the volume of a gas is empty space.

2 compressibility

a. A gas and a liquid are equally compressible.

b. A gas is less compressible because of large intermolecular distances.

c. A gas is much more compressible because of the distance between molecules.

d. A gas is much more compressible because it does not have any intermolecular forces.

3 ability to mix with other substances of the same phase to form homogeneous mixtures

a. Gases mix easily because of large intermolecular distances and form homogeneous mixtures, while liquids do not always form homogeneous mixtures. In liquids, only similar molecules will displace each other to form homogeneous mixtures.

b. Gases do not always form homogeneous mixtures because of large intermolecular distances. Liquids always form homogeneous mixtures due to smaller intermolecular distances.

c. Gases and liquids always mix homogeneously with other substances of the same phase, while solids do not mix.

d. Gases always mix homogeneously because of lower masses. Liquids with the same density always mix homogeneously, and liquids with different densities never form homogeneous mixtures.

4 ability to conform to the shape of its container

a. Gases and liquids conform to the shape of their containers because of their low compressibility, but only gases conform to the volume of their container because of stronger intermolecular forces.

b. Gases and liquids conform to the shape of their containers because their molecules are constantly moving, but only gases conform to the volume of their container because of stronger intermolecular forces.

c. Gases and liquids conform to the shape of their containers spontaneously because their molecules are constantly moving, but only gases conform to the volume of their container because of large intermolecular distances.

d. Gases and liquids conform to the shape of their containers because of strong intermolecular forces, but only gases conform to the volume of their container because of a lower compressibility than liquids.