Chemistry 1 Unit 7 Review

Which of these materials transfers heat energy the quickest?

• metal

• glass

• plastic

• wood

Endothermic reactions are reactions that require more energy to start than they give off in the products. Which statement describes an endothermic process?

• Gives off heat energy and is hot to the touch

• Absorbs heat energy and is cool to the touch

• Gives off light energy and produces visible light

• Gives off water and is wet to the touch

When coal burns, the reaction....

• releases heat and is endothermic.

• releases heat and is exothermic.

• absorbs heat and is endothermic.

• absorbs heat and is exothermic.

A student dissolves solid sodium hydroxide in water and observes an increase in the water's temperature. How is this process classified?

• The process is exothermic because energy is released.

• The process is exothermic because energy is absorbed.

• The process is endothermic because energy is absorbed.

• The process is endothermic because energy is released.

A researcher investigates the effect of temperature on the pressure of a gas by sealing 10 g of nitrogen gas in a closed container with an attached pressure gauge and placing the container on a hot plate to increase the temperature. What is the independent variable?

• the temperature of the gas

• the pressure of the gas

• the time required for the temperature to change

• the mass of the container