Question

chapter 3 states of matter
multiple choice
write the letter that best answers the question or completes the statement on the line provided.

1. a gas has

a. a definite volume but no definite shape.
b. a definite shape but no definite volume.
c. no definite shape or definite shape.
d. a definite volume and definite shape.

1. matter that has a definite volume but no definite shape is a

a. liquid. b. solid.
c. gas. d. plasma.
figure 3 - 1

1. in which of the substances in figure 3 - 1 are the forces of attraction among the particles so weak that they can be ignored under ordinary conditions?

a. substance a b. substance b
c. substance c d. all of the above

1. what is the result of a force distributed over an area?

a. temperature b. volume
c. pressure d. mass

1. which of the following factors affect the pressure of an enclosed gas?

a. temperature b. volume
c. number of particles d. all of the above

1. the temperature and volume in a closed container of gas remain constant. if the number of particles of gas is increased, the gas pressure will

a. increase.
b. decrease.
c. remain constant.
d. cause a decrease in the average kinetic energy of the particles.

Explanation:

1. Gases have a definite volume (the volume of their container) but take the shape of their container, so no definite shape.
2. Liquids have a definite volume but no definite shape. Solids have both definite volume and shape. Plasma is a high - energy state. A liquid has a definite volume but no definite shape.
3. In gases, the forces of attraction between particles are very weak. Substance C appears to be a gas with widely spaced particles.
4. Pressure is defined as force per unit area.
5. The pressure of an enclosed gas is affected by temperature (Gay - Lussac's law), volume (Boyle's law), and the number of particles (Avogadro's law).
6. According to the ideal gas law $PV = nRT$, when $V$ and $T$ are constant, an increase in $n$ (number of particles) leads to an increase in $P$ (pressure).

Answer:

1. a. a definite volume but no definite shape.
2. a. liquid.
3. c. Substance C
4. c. pressure
5. d. all of the above
6. a. increase.