Show all calculations and trials in your notebook and/or Excel. Report a sample
ID: 997114 • Letter: S
Question
Show all calculations and trials in your notebook and/or Excel. Report a sample trial here. Mass of ammonium chloride(for mole calculation) Number of moles of ammonium chloride Initial temperature of 25 ml water Final temperature of solution Heat absorbed from surroundings (by the solution) DeltaH/mole for the dissolution Average DeltaH/mole for the dissolution and range Show your calculation of the standard deviation. $. from d^2 below: Minimum average DeltaS value for this reaction 2. When hydrogen peroxide decomposes (Part 1 of the experiment), teh temperature rises. A fellow student argues that this means that heat must be taken in from the surroundings rather than heat being evolved to the surroundings. The same student of course wants to believe that when ammonium chloride dissolves (Part 3) and the temperature decreases, this is because heat is "lost" or evolved to the surroundings, causing the measured temperature to drop. In your notbook write, as clearly as you can, a rebuttal of this false "logic". Do not forget good English and organizational skills, as well as your understanding of the issues.Explanation / Answer
when chemical reactions take place, From law of conservation of energy, energy can neither be created nor destroyed, Hence when a system picks up heat ( gains energy) there has to be loss of energy from the surroundins. For example, when H2O2 decomposes, the heat content of products is less than the the heat content of reactants leading to heat liberattion and this heat has to come from surroundings
The same thing is true for endothermic reactions where heat is added to surroundings.