8. Thermochemistry

Which equation is commonly used to calculate the change in thermal energy (q) of a substance during a temperature change?

How many BTUs are required to convert 1 pound of ice at 20°F to steam at 220°F?

Which energy changes are associated with a liquid boiling?

How much energy is released when 42.5 g of water freezes at 0°C? (The enthalpy of fusion for water is 334 J/g.)

What happens when hot water is added to cold water in an insulated container?

A 15.0-g sample of ice at -15.0 °C is heated until it becomes liquid water at 45.0 °C. How much energy (in joules) is required for this process? (Given: specific heat of ice = 2.09 J/g·°C, specific heat of water = 4.18 J/g·°C, heat of fusion of ice = 334 J/g)

When 20.0 g of water at 25 °C is mixed with 30.0 g of water at 80 °C in an insulated container, what is the final temperature of the mixture? (Assume no heat loss to the surroundings and that the specific heat capacity of water is 4.18 J/g·°C.)

Which of the following best describes what occurs at thermal equilibrium?

While water is in the process of freezing, what happens to its temperature?

What is most likely to occur if you continuously increase the temperature of a liquid at atmospheric pressure?

In a sauna, why is only a small ladle-full of water poured onto the hot rocks at one time?

Which of the following indicates that thermal energy is no longer being transferred from boiling water to a mug?

Which process best explains how ice cools a warm drink?

A 2.0 kg metal weight at 80 °C is placed into 1.0 kg of water at 20 °C in an insulated container. Assuming no heat is lost to the surroundings and the specific heat capacity of the metal is 0.45 J/g·°C and that of water is 4.18 J/g·°C, what is the final temperature of both the weight and the water at thermal equilibrium?

Why is it important that the thermometer does not touch the sides or bottom of the test tube when measuring temperature during an experiment involving thermal equilibrium?