You are provided with a 150 g sample of an unknown metal M of unspecified initial temperature. The sample is transferred as quickly as possible into a coffee-cup calorimeter that contains 200.0 g of water initially at 23.0 °C. After thorough stirring, the final temperature of the water–metal system is observed to be 27.8 °C. Assume that any heat loss to the calorimeter itself or to the surroundings can be neglected.
(a) Design a step-by-step experimental procedure, including any necessary measurements, that would allow you to determine both the direction and the magnitude of heat flow between the metal sample and the water.
(b) Identify all variables that must be controlled to ensure the reliability of your experimental results, and explain the consequence of failing to control each one.
(c) Using particulate-level reasoning, explain how the experimental data you collect can be used to infer the initial temperature of the metal sample and to verify the direction of energy transfer.
(d) Discuss two significant sources of experimental error (other than heat loss to the surroundings) and analyze how each would affect the accuracy of your conclusions regarding the heat flow direction and magnitude.