Answer to Question #157101 in Analytical Chemistry for ahmed haj

Question

A student did an experiment to determine the specific heat capacity of a metal alloy. The student put a sample of the alloy in boiling water for several minutes, then quickly transferred the alloy into a calorimeter containing water originally at . The temperature of the water was monitored over time. The data are given in the graph above.

(a) What is the value of delta T that the student should use to calculate the value of q , the heat gained by the water?

b) In terms of what occurs at the particulate level, explain how the temperature of the water increases after the alloy sample is added.

c) The student claims that thermal equilibrium is reached at time . Justify the student’s claim. In your justification, include a description of what occurs at the particulate level when the alloy and the water have reached thermal equilibrium.

Answer 1

a) ∆T=T1-T2

b) At the particle level the temperature changes are the result of the added energy causing the particles of water to move more vigorously. Either the particles of solid vibrate more vigorously about their fixed positions or the particles of liquid and gas move about their container more rapidly.

c) The condition under which two substances in physical contact with each other exchange no heat energy. Two substances in thermal equilibrium are said to be at the same temperature. See also thermodynamics.