Heat (18q)

Which form of energy is transferred when an ice cube at 0°C is placed in a beaker of water at 70°C?

• chemical

• electrical

• thermal

• nuclear

Which of the following would have a crystalline structure?

• H₂O (s)

• H₂O (l)

• H₂O (g)

• H₂O (aq)

What occurs when a 35-gram aluminum cube at 100°C is placed in 90. grams of water at 25°C in an insulated cup?

• Heat is transferred from the aluminum to the water, and the temperature of the water decreases.

• Heat is transferred from the aluminum to the water, and the temperature of the water increases.

• Heat is transferred from the water to the aluminum, and the temperature of the water decreases

• Heat is transferred from the water to the aluminum, and the temperature of the water increases.

What is entropy?

• The amount of heat a reaction produces

• The amount of heat a reaction releases

• A measure of the disorder in a system

Which unit is used to express the energy absorbed or released during a chemical reaction?

• kelvin

• joule

• volt

• torr

Which kind of energy is stored within a chemical substance?

• free energy

• activation energy

• kinetic energy

• potential energy

The temperature of a substance is a measure of the

• average kinetic energy of its particles

• average potential energy of its particles

• ionization energy of its particles

• activation energy of its particles

In which sample of water do the molecules have the highest average kinetic energy?

• 20. mL at 100.°C

• 40. mL at 80.°C

• 60. mL at 60.°C

• 80. mL at 40.°C

Which Kelvin temperature is equal to –73ºC?

• 100 K

• 173 K

• 200 K

• 346 K

Which change of phase is exothermic?

• solid to liquid

• gas to liquid

• solid to gas

• liquid to gas