GRE Subject Test: Chemistry › Phases of Matter
A gas sample is contained in a 4L vessel at a pressure of 3atm. Assuming all other conditions are kept constant, what is the new pressure in the vessel if the volume is reduced to 1.5L?
According to Boyle's law, pressure and volume are inversely proprotional to each other. This is represented by the equation:
In other words, as volume decreases in a vessel, the pressure will increase, and vice versa. Using the given conditions, we can solve for the final pressure in the vessel:
A gas sample is contained in a 4L vessel at a pressure of 3atm. Assuming all other conditions are kept constant, what is the new pressure in the vessel if the volume is reduced to 1.5L?
According to Boyle's law, pressure and volume are inversely proprotional to each other. This is represented by the equation:
In other words, as volume decreases in a vessel, the pressure will increase, and vice versa. Using the given conditions, we can solve for the final pressure in the vessel:
A gas sample is contained in a 4L vessel at a pressure of 3atm. Assuming all other conditions are kept constant, what is the new pressure in the vessel if the volume is reduced to 1.5L?
According to Boyle's law, pressure and volume are inversely proprotional to each other. This is represented by the equation:
In other words, as volume decreases in a vessel, the pressure will increase, and vice versa. Using the given conditions, we can solve for the final pressure in the vessel:
Which of the following describes a transition from gas to solid?
Deposition
Sublimation
Fusion
Vaporization
Crystallization
There are six possible phase changes between the three phases of matter. Deposition describes the change from gas to solid, while sublimation describes the transition from solid to gas. Freezing (crystallization) is the transition from liquid to solid, while fusion (melting) is the transition from solid to liquid. Condensation is the transition from gas to liquid, while vaporization (boiling) is the transition from liquid to gas.
Which of the following describes a transition from gas to solid?
Deposition
Sublimation
Fusion
Vaporization
Crystallization
There are six possible phase changes between the three phases of matter. Deposition describes the change from gas to solid, while sublimation describes the transition from solid to gas. Freezing (crystallization) is the transition from liquid to solid, while fusion (melting) is the transition from solid to liquid. Condensation is the transition from gas to liquid, while vaporization (boiling) is the transition from liquid to gas.
Which of the following describes a transition from gas to solid?
Deposition
Sublimation
Fusion
Vaporization
Crystallization
There are six possible phase changes between the three phases of matter. Deposition describes the change from gas to solid, while sublimation describes the transition from solid to gas. Freezing (crystallization) is the transition from liquid to solid, while fusion (melting) is the transition from solid to liquid. Condensation is the transition from gas to liquid, while vaporization (boiling) is the transition from liquid to gas.
Which of the following is relevant for real gases, but irrelevant for ideal gases?
I. Volume of gas particles
II. Intermolecular forces between gas particles
III. Volume of container
I and II
I only
III only
I and III
There are two main assumptions for an ideal gas (and a few smaller assumptions). First, the gas particles of the ideal gas must have no molecular volume. Second, the gas particles must exert no intermolecular forces on each other; therefore, forces such hydrogen bonding, dipole-dipole interactions, and London dispersion forces are irrelevant in ideal gases. Other small assumptions of ideal gases include random particle motion (no currents), lack of intermolecular interaction with the container walls, and completely elastic collisions (a corollary of zero intermolecular forces).
For real gases, however, these assumptions are invalid. This means that the real gas particles have molecular volume and exert intermolecular forces on each other.
Recall that the volume in the ideal gas law is the volume of the free space available inside the container. For ideal gases, the free space volume is equal to the volume of the container because the gas particles take up no volume; however, for real gases, the free space volume is the volume of the container minus the volume of the gas particles. Though the exact values of free space volume will differ, the volume of the container is important for both real and ideal gases.
Which of the following is relevant for real gases, but irrelevant for ideal gases?
I. Volume of gas particles
II. Intermolecular forces between gas particles
III. Volume of container
I and II
I only
III only
I and III
There are two main assumptions for an ideal gas (and a few smaller assumptions). First, the gas particles of the ideal gas must have no molecular volume. Second, the gas particles must exert no intermolecular forces on each other; therefore, forces such hydrogen bonding, dipole-dipole interactions, and London dispersion forces are irrelevant in ideal gases. Other small assumptions of ideal gases include random particle motion (no currents), lack of intermolecular interaction with the container walls, and completely elastic collisions (a corollary of zero intermolecular forces).
For real gases, however, these assumptions are invalid. This means that the real gas particles have molecular volume and exert intermolecular forces on each other.
Recall that the volume in the ideal gas law is the volume of the free space available inside the container. For ideal gases, the free space volume is equal to the volume of the container because the gas particles take up no volume; however, for real gases, the free space volume is the volume of the container minus the volume of the gas particles. Though the exact values of free space volume will differ, the volume of the container is important for both real and ideal gases.
Which of the following is relevant for real gases, but irrelevant for ideal gases?
I. Volume of gas particles
II. Intermolecular forces between gas particles
III. Volume of container
I and II
I only
III only
I and III
There are two main assumptions for an ideal gas (and a few smaller assumptions). First, the gas particles of the ideal gas must have no molecular volume. Second, the gas particles must exert no intermolecular forces on each other; therefore, forces such hydrogen bonding, dipole-dipole interactions, and London dispersion forces are irrelevant in ideal gases. Other small assumptions of ideal gases include random particle motion (no currents), lack of intermolecular interaction with the container walls, and completely elastic collisions (a corollary of zero intermolecular forces).
For real gases, however, these assumptions are invalid. This means that the real gas particles have molecular volume and exert intermolecular forces on each other.
Recall that the volume in the ideal gas law is the volume of the free space available inside the container. For ideal gases, the free space volume is equal to the volume of the container because the gas particles take up no volume; however, for real gases, the free space volume is the volume of the container minus the volume of the gas particles. Though the exact values of free space volume will differ, the volume of the container is important for both real and ideal gases.
Boiling points at standard temperature and pressure:
Methanol-
Toluene-
Water-
Methylene chloride-
Dimethylsulfoxide-
Of the five compounds given, which will have the highest vapor pressure at standard temperature and pressure?
Methylene chloride
Methanol
Water
Dimethylsulfoxide
Toluene
A liquid will boil when its vapor pressure increases to match the pressure of its environment. By this logic, a liquid with a higher vapor pressure will be closer to boiling. Liquids with low boiling points thus have greater vapor pressures.
Of the given compounds, methylene chloride has the lowest boiling point, meaning it will also have the highest vapor pressure.