Use the following scenario to answer questions 1-4. Question 1 Into a well insul
ID: 1001607 • Letter: U
Question
Use the following scenario to answer questions 1-4.
Question 1 Into a well insulated cup (meaning no heat lost or gained to the surroundings) a sample of water at room temperature is added. To the water, a sample of metal at 80 oC is added. What object(s) gain(s) energy? Choose all that apply
Question 2 What is the relationship between the heat gained and the heat lost by the objects? A. The heat lost is greater than the heat gain. B. The heat gained is greater than the heat lost. C. The heat gained is equivilant to the heat lost. D. The heat gained and lost depend on the relative temperatures and therefore the relationship cannot be determined with the information given.
Question 3 What is the relationship between the final temperatures of the metal and the water? A. When equilibrium is established, temperature of the metal will be greater than that of water. B When equilibrium is established, temperature of the metal will be less than that of water. C. When equilibrium is established, temperature of the metal will be the same as that of water. D. It depends on the masses and initial temperatures of the materials, therefore it cannot be determined.
Question 4 What is the relationship between the change in temperature of the objects? A. The metal will change in temperature more than the water. B. The water will change in temperature more than the metal. C. The water and metal will have the same temperature change. D. It depends on the masses and heat capacities of the substances, so it cannot be determined with the information given.
Question 5 How much energy (in Joules) is required to heat 13.61 g of water from 17.8 oC to 49.5 oC ? Use 4.184 J/goC as the specific heat capacity of water.
Question 6 An unknown metal is found to have a specific heat capactiy of 0.281. From this, calculate its molar mass
Question 7 A student measures the initial temperature of an object as 31.11oC and the final temperature as 53.78 oC. What is the change in temperature in units of Kelvin?
Question 8 52.77 g of water at 82.1 oC is added to a calorimeter that contains 47.71 g of water at 42.3 oC. If the final temperature of the system is 59.4 oC, what is the calorimeter constant (Ccalorimeter) ? Use 4.184 J/goC for the heat capacity of water.
Explanation / Answer
Question 1 Into a well insulated cup (meaning no heat lost or gained to the surroundings) a sample of water at room temperature is added. To the water, a sample of metal at 80 oC is added. What object(s) gain(s) energy? Choose all that apply
Answer: the heat will be gained by water and lost by metal as water is at lower temperature
Question 2 What is the relationship between the heat gained and the heat lost by the objects?
answer: According the first law of thermodynamics, heat can neither be created nor be destroyed however can be transfered from one object or process to other.
So correct statement is:The heat gained is equivilant to the heat lost
Question 3 What is the relationship between the final temperatures of the metal and the water?
Answer: The heat gained will be equal to heat loss, the process will attain equilibrium when the temperature of water and metal will become equal to each other.
When equilibrium is established, temperature of the metal will be the same as that of water.
Question 4 What is the relationship between the change in temperature of the objects?
Answer:
Heat gained by water = heat loss by metal
mass of water X specific heat of water X change in temperature = Mass of metal X specific heat of metal X change in temperature
the final temperature will be same
So the change in temperature depends on the masses and heat capacities of the substances, so it cannot be determined with the information given.
Question 5 How much energy (in Joules) is required to heat 13.61 g of water from 17.8 oC to 49.5 oC ? Use 4.184 J/goC as the specific heat capacity of water.
Answer:
Q = mass X specific heat X change in temperature = 13.61 X (49.5-17.8) X 4.184 = 1805.13 Joules
Question 7 A student measures the initial temperature of an object as 31.11oC and the final temperature as 53.78 oC. What is the change in temperature in units of Kelvin?
Answer: change in temperature in kelving will be same as of in degree celsius = 53.78-31.11 = 22.67 K
Question 8 52.77 g of water at 82.1 oC is added to a calorimeter that contains 47.71 g of water at 42.3 oC. If the final temperature of the system is 59.4 oC, what is the calorimeter constant (Ccalorimeter) ? Use 4.184 J/goC for the heat capacity of water.
Answer:
Heat gained = Heat loss
Q = mass X specific heat X change in temperature
= 52.77 X 4.184 X (82.1 -59.4) = 47.71 X calorimeter constant X (59.4-42.3)
Calorimeter constant = 5011.92 / 815.84
Calorimeter constant = 6.14 J / g 0C