PHY_10_V1_DM_Revision term 2

Molecular physics:

1.      What is the first assumption of the Kinetic Theory of Matter?

2.      What determines how close molecules are to each other?

3.      What happens when particles collide?

4.      Which is not a phase of matter?

5.      Which statement about the particle theory of matter is true?

6.      Which statement is not a key point of the particle theory of matter?

7.      Which of the physical states of water contains particles with the lowest kinetic energy?

8.      When any kind of gas such, as nitrogen or carbon dioxide, is heated, it

9.      The force of attraction is greatest between the particles of a

10.  According to kinetic molecular model, in gases

Gas laws: 

1        atm  =  760.0 mm Hg  = 101.3 kPa= 760 .0 torr

11.  A gas balloon has a volume of 106.0 liters when the temperature is 45.0 °C and the pressure is 740.0 mm of mercury. What will its volume be at 20.0 °C and 780 .0 mm of mercury pressure?

12.  If 10.0 liters of oxygen at STP are heated to 512 °C, what will be the new volume of gas if the pressure is also increased to 1520.0 mm of mercury?

Fundamentals of thermodynamics:

13.   (a)     The first law of thermodynamics can be written ΔQ = ΔU + ΔW

State the usual meaning of each term in the equation.

ΔQ ______________________________________________________________

ΔU ______________________________________________________________

ΔW ______________________________________________________________

 (b)     A fixed mass of gas in a cylinder is heated in two stages:

stage 1 at constant volume, when 10.0 kJ of heat is supplied,
stage 2 when it expands isothermally and does 6.0 kJ of work.

Apply the first law of thermodynamics to each of these processes and complete the table to show, for each process, the values of ΔQ, ΔU and ΔW.

Liquid and solid bodies:

14.  The surface tension and viscosity of water at several different temperatures are given in this table.

1. As temperature increases, what happens to the surface tension of water? Explain why this occurs, in terms of molecular interactions and the effect of changing temperature.
2. As temperature increases, what happens to the viscosity of water? Explain why this occurs, in terms of molecular interactions and the effect of changing temperature.

Answer a

As the water reaches higher temperatures, the increased kinetic energies of its molecules are more effective in overcoming hydrogen bonding, and so its surface tension decreases. Surface tension and intermolecular forces are directly related.

Answer b

The same trend in viscosity is seen as in surface tension, and for the same reason.

15.  Why are soap bubbles spherical?

How do you make lead shot (small spherical lead balls)?

What is the difference between wet and dry hairs on a brush?

What is the difference when you hair is wet compared to when dry?

Strong students should solve problem in addition

A thin, circular wire of diameter 40 mm and total mass of 0.70 g is gently pulled vertically from a water surface by a sensitive spring (k = 0.70 N.m^-1). When the spring is stretched 34 mm from its equilibrium position in air the ring is on the verge of being pulled free from the water surface. Find the coefficient of surface tension of water. Neglect the mass of water lifted.