Unit 3 Exam 2 & 1

When two samples of ideal gases have the same

______, their molecules must have the same ______.

KMT

• Gases are all hard spheres

• They are small relative to size of system volume

• They undergo elastic collisions and don’t stick or react

• They have a T equal system T that gives all of them the same Ek

• They all have the same Ek, but Ek = 1⁄2 mv2 so they have different velocity as inverse square of mass

 $m_1v_1^2=m_2v_2^2$  

Ideal conditions:

• P is low so don't collide

• V is large so don't collide

• n is small so don’t collide

• T is large so don’t stick

• gases are small and nonpolar so don’t stick

Van der Whalls equation for non-ideality

(no spaces inbetween)

Gas X has a larger value than gas Y for the Van der

Waals constant "a". This indicates that

• 1. The molecules of X have stronger

  intermolecular attractions for each other than

  the molecules of Y have for each other

• 2. The molecules of X are larger than the

  molecules of Y

• 3. The molecules of gas X have a higher velocity

  than the molecules of gas Y

• 4. The molecules of has X repel other X

  molecules

a corrects

• stickiness

• size

• polarity

b corrects

• stickiness

• size

• polarity

Ideal Gases

• He

• H2

• H2O

• NH3

Ideal Gases

• nonpolar

• small

• large

• polar