Fall Semester Chemistry Review Kaye

A sample of water is boiling as heat is added at a constant rate. Which statement describes the potential energy and the average kinetic energy of the water molecules in this sample?

• The potential energy decreases and the average kinetic energy remains the same.

• The potential energy decreases and the average kinetic energy increases.

• The potential energy increases and the average kinetic energy remains the same.

• The potential energy increases and the average kinetic energy increases.

Tags

NGSS.HS-PS3-2

Which of the following is characteristic of exothermic reactions?

• Increase the temperature of the surroundings by giving off heat

• Decrease the temperature of the surroundings by giving off heat

• Increase the temperature of the surroundings by absorbing heat

• Decrease the temperature of the surroundings by absorbing heat

Tags

NGSS.HS-PS1-4

For which compound is the process of dissolving in water exothermic?

(Use Table I) Dissolving has water above the arrow. Read the notes at the bottom of chart.

negative delta H means...

positive delta H means....

• NaCl

• NaOH

• NH₄NO₃

• NH₄Cl

Tags

NGSS.HS-PS1-4

The graph below represents the uniform heating of a substance, starting with the substance as a solid below its melting point. Which line represents an increase in potential energy and no change in kinetic energy?

• CD

• AB

• BC

• EF

Given the cooling curve of a substance below, during which interval is potential energy decreasing and average kinetic energy remaining constant?

• AB and BC

• AB and CD

• DE and BC

• DE and EF

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-2

Two samples of gold at different temperatures are placed in contact with one another. Heat energy (thermal energy) will flow spontaneously from a sample at 60 degrees Celsius to a sample that has a temperature of

• 50 degrees Celsius

• 60 degrees Celsius

• 80 degrees Celsius

• 70 degrees Celsius

Tags

NGSS.HS-PS3-4

A 100 gram piece of brass at a temperature of 100°C is dropped into 100 grams of water that has a temperature of 20°C. Which of the following describes what happens next?

• Thermal energy is transferred from the brass to the water and the temperature of the brass decreases.

• Thermal energy is transferred from the water to the brass and the temperature of the brass decreases.

• Thermal energy is transferred from the water to the brass and the temperature of the brass increases.

• Thermal energy is transferred from the brass to the water and the temperature of the brass increases.

Tags

NGSS.HS-PS3-4

Which equation represents sublimation?

• H₂O (l) → H₂O (s)

• He (l) → He (g)

• CO₂ (g) → CO₂ (s)

• I₂ (s) → I₂ (g)

Tags

NGSS.MS-PS1-4

A 220.0-mL sample of helium gas is in a cylinder with a movable piston at 105 kPa and 275 K. The piston is pushed in until the sample has a volume of 95.0 mL. The new temperature of the gas is 310. K. What is the new pressure of the sample?

• 243 kPa

• 216 kPa

• 51.1 kPa

• 274 kPa

A sample of helium gas has a volume of 900. milliliters and a pressure of 2.50 atm at 298 K. What is the new pressure when the temperature is changed to 336 K and the volume is decreased to 450. milliliters?

• 0.177 atm

• 4.43 atm

• 5.64 atm

• 14.1 atm