All Flashcards
What are the basic steps for using a coffee-cup calorimeter?
- Set up the calorimeter with thermometer, stirrer, and insulated container. 2. Add reactants and initiate the reaction. 3. Measure the temperature change. 4. Calculate heat transfer using q = mCΔT.
How do you calculate heat transfer (q)?
Use the equation: q = mCΔT, where m is mass, C is specific heat, and ΔT is the change in temperature.
Explain the steps to determine the specific heat of a metal using calorimetry.
- Heat the metal to a known temperature. 2. Place the metal in water within a calorimeter. 3. Measure the final temperature of the water and metal. 4. Use mcΔT (metal) = mcΔT (water) to solve for the specific heat of the metal.
What is the effect of high specific heat on temperature change?
The higher the specific heat, the more energy it takes to change the temperature of a substance.
What happens if a calorimeter is not perfectly insulated?
Heat will be lost to the surroundings, leading to inaccurate measurements of heat transfer.
What is the effect of adding heat to a substance?
The temperature of the substance increases (unless it's undergoing a phase change).
What is the effect of the first law of thermodynamics on calorimetry?
The total energy in the calorimeter remains constant; heat lost by one substance equals heat gained by another.
Compare and contrast q and ΔH.
q: Magnitude of heat transfer (always positive). ΔH: Enthalpy change, can be positive (endothermic) or negative (exothermic).
Compare water and sand in terms of specific heat.
Water: High specific heat (4.184 J/g°C), heats up slowly. Sand: Low specific heat (around 0.840 J/g°C), heats up quickly.