Anonymous
Anonymous asked in Science & MathematicsChemistry · 1 month ago

# 4 Multiple Choice CHEM QUESTIONS!?

#1. Which of the following does not follow the kinetic molecular theory?

A-Gas molecules have negligible volume.

B-Gas molecules do not have mass.

C-The average kinetic energy of gas molecules is proportional to the temperature of the gas molecules.

D-Gas molecules possess no attraction or repulsion to one another.

#2. If the Kelvin temperature of a substance has doubled, we can say:

A- the kinetic energy of the substance has been halved

B- the kinetic energy of the substance is tripled

C- the kinetic energy of the substance has doubled

D- the kinetic energy of the substance is unaffected

#3. The average kinetic energy of 1 mole of a gas at 0 Kelvin is:

A- 1.237 x 101 J

B- 5.543 x 100 J

C- 0 J

D- 8.314 x 100 J

#4. The average kinetic energy of 1 mole of a gas at standard temperature is:

A- 0 J

B- 3.40 x 103 J

C- 1.51 x 103 J

D- 3.36 x 101 J

Relevance

Kinetic molecular theory.

1. The KMT does not say that molecules have no mass.

2. Doubling absolute T doubles the KE..... KE = 3/2RT

3. 0K cannot be reached. As T approaches 0K, KE approaches 0

4. KE = 3/2 (8.314 J/molK) x 273.15K = 3406 J/mol

----------------------

The average kinetic energy can be expressed in two ways:

.... KE = 3/2RT

.... KE = ½mv² ............ KE = ½Mu² ..... where u is the RMS speed

Which gives rise to ....

3/2 RT = 1/2 mv²

3RT = Mu²

u = √(3RT/M) ........... speed of the molecules is directly proportional to the absolute temperature and inversely proportional to the molar mass

At absolute zero molecular motion reaches a minimum, not zero (it's a quantum theory thing). Absolute zero cannot be reached, only approached. As absolute zero is approached, matter can become an exotic condensed state.

• Login to reply the answers
• #1. B. Kinetic theory does not have mass as a factor.

#2 C. Kinetic energy is directly proportional to temperature.

#3 C. All molecular motion stops at 0K.

• pisgahchemist
Lv 7
1 month agoReport

Molecular motion reaches a minimum at 0K.  It is no longer accurate to say that all molecular motion stops at absolute zero.

• Login to reply the answers