Asample of argon fills a volume of 5 m3 at 425 k with a pressure of 3.9 atm. the argon is cooled to 240 k and shrinks to a volume of 3.1 m3. after cooling it is added to a tank of helium with a pressure of 1.87 atm. what is the total pressure of the gas mixture? a. 3.55 atm b. 2.89 atm c. 13.0 atm d. 5.42 atm

D. 5.42 atm.

Explanation:

The total pressure of the gas mixture = P of He + P of Ar after cooling.

P of He = 1.87 atm.

We can use the general law of ideal gas: PV = nRT.

where, P is the pressure of the gas in atm.

V is the volume of the gas in L.

n is the no. of moles of the gas in mol.

R  is the general gas constant,

T is the temperature of the gas in K.

(P₁V₁T₂) = (P₂V₂T₁)

P₁ = 3.9 atm, V₁ = 5.0 m³, T₁ = 425.0 K,

P₂ = ??? atm, V₂ = 3.1 m³, T₂ = 240.0 K,

(P₁V₁T₂) = (P₂V₂T₁)

∴ P₂ = (P₁V₁T₂)/(V₂T₁) = (3.9 atm)(5.0 m³)(240 K)/(3.1 m³)(425.0 K) = 3.552 atm.

∴ The total pressure of the gas mixture = P of He + P of Ar after cooling.

P of He = 1.87 atm & P of Ar after cooling = 3.552 atm.

∴ The total pressure of the gas mixture = 1.87 atm + 3.552 atm = 5.422 atm ≅ 5.42 atm.

So, the right choice is: D. 5.42 atm.

explanation:

the largest database of organic compounds lists about 10 million substances, which include compounds originating from living organisms and those synthesized by chemists. the number of potential organic compounds has been estimated at 1060—an astronomically high number. the existence of so many organic molecules is a consequence of the ability of carbon atoms to form up to four strong bonds to other carbon atoms, resulting in chains and rings of many different sizes, shapes, and complexities. the simplest organic compounds contain only the elements carbon and hydrogen, and are called hydrocarbons. even though they are composed of only two types of atoms, there is a wide variety of hydrocarbons because they may consist of varying lengths of chains, branched chains, and rings of carbon atoms, or combinations of these structures. in addition, hydrocarbons may differ in the types of carbon-carbon bonds present in their molecules. many hydrocarbons are found in plants, animals, and their fossils; other hydrocarbons have been prepared in the laboratory. we use hydrocarbons every day, mainly as fuels, such as natural gas, acetylene, propane, butane, and the principal components of gasoline, diesel fuel, and heating oil. the familiar plastics polyethylene, polypropylene, and polystyrene are also hydrocarbons. we can distinguish several types of hydrocarbons by differences in the bonding between carbon atoms. this leads to differences in geometries and in the hybridization of the carbon orbitals.

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.