7. Energy, Rate and Equilibrium

Heat Capacity

Multiple Choice
50.00 g of heated metal ore is placed into an insulated beaker containing 822.5 g of water. Once the metal heats up the final temperature of the water is 32.08 ºC. If the metal gains 14.55 kJ of energy, what is the initial temperature of the water? The specific heat capacity of copper is 4.184 J / g  ºC.
Multiple Choice
A sample of copper absorbs 3.53 kJ of heat, which increases the temperature by 25 ºC, determine the mass (in kg) of the copper sample if the specific heat capacity of copper is 0.385 J / g  ºC.
Multiple Choice
Based on their given specific heat capacities which compound would show the greatest temperature change upon absorbing 25.0 J of heat?
Open Question
Assuming that Coca-Cola has the same specific heat as water, how much energy in calories is removed when 350 g of Coca-Cola (about the contents of one 12 oz can) is cooled from room temperature ( 25 ° C ) to refrigerator temperature ( 3 ° C )?
Open Question
If the same amount of heat is supplied to samples of 10.0g each of aluminum, iron, and copper all at 15.0 °C, which sample would reach the highest temperature (see TABLE3.11)?
Open Question
Use the heat equation to calculate the energy, in joules and calories, for each of the following (see TABLE3.11):c. lost when 15.0 g of ethanol, C₂H₆O, cools from 60.5 °C to−42.0 °C
Open Question
Calculate the energy to heat twocubes (gold and aluminum) each with a volume of 10 cm³ from 15 °C to 25 °C. Refer to Tables2.8 and 3.11. (3.6)
Open Question
Calculate the specific heat of copper if it takes 23 cal (96 J) to heat a 5.0 g sample from 25 degree C to 75 degree C.
Open Question
The specific heat of fat is 0.45 cal/(g ⋅ °C) (1.9 J/g °C) and the density of fat is 0.94 g/cm^3. How much energy (in calories and joules) is needed to heat 10 cm^3 of fat from room temperature (25 degree C) to its melting point (35 degree C)?
Open Question
hen 100 cal (418 J) of heat is applied to a 125 g sample, the temperature increases by 28 degree C. Calculate the specific heat of the sample and compare your answer to the values in Table 1.10. What is the identity of the sample?
Open Question
On a hot day, the beach sand gets hot but the water stays cool. Would you predict that the specific heat of sand is higher or lower than that of water? Explain. (3.6)
Open Question
A metal is thought to be titanium or aluminum. When 4.7 g of the metal absorbs 11 J, its temperature rises by 4.5 °C. (3.6)b. Would you identify the metal as titanium or aluminum (seeTABLE3.11)?
Open Question
A metal is thought to be copper or gold. When 18 g of themetal absorbs 58 cal, its temperature rises by 35 °C. (3.6)a. What is the specific heat, in cal/g °C, of the metal?
Open Question
When 1.0 tablespoon of butter is burned or used by our body, it releases 100 kcal (100 food Calories or 418. 4 kJ) of energy. If we could use all the energy provided, how many tablespoons of butter would have to be burned to raise the temperature of 3.00 L of water from 18.0 ℃ to 90.0 ℃
Open Question
An archeologist finds a 1.62 kg goblet that she believes to be made of pure gold. When 1350 cal (5650 J) of heat is added to the goblet, its temperature increases by 7.8 ℃. Calculate the specific heat of the goblet. Is it made of gold? Explain.