SCIENCE REPORTAMMONIUM NITRATENH4NO3ProblemOur task was to investigate what the optimum ratio of solute to solvent that will produce the maximum cooling/heating effect?HypothesisWith a smaller quantity of water (50mls) and the same amount of Ammonium Nitrate added.
After any period of time the mixture will be a cooler temperature than that of a mixture with a larger quantity of water. Variables,XWater,XTeaspoons,XTime,XAmmonium Nitrate,XThermometer,XStirring (used thermometer),Changed/Uncontrolled Variables-The amount of times the mixture was stirred. We stirred the mixture until the Ammonium Nitrate was dissolved, so the amount of times we stirred after each teaspoon was different. -Each teaspoon may not have been equal. Measurements were made based on judgment and not exact measurements. ,Controlled Variables-Amount of water used in each test was equal (100mls and 50mls).
-Total amount of Ammonium Nitrate used (150grams). -Temperature was measured after and exact time i. e. 1 minute, 2 minutes, 3 minutes. EquipmentTrial test,X1 thermometer,X1 plastic teaspoon,XSafety glasses,X100ml beaker,X30mls of water,X1 teaspoon of Ammonium Nitrate,X1 graduated cylinder,X1 stirring rodFirst Test,X1 thermometer,X1 plastic teaspoon,X1 stop watch,X1 stirring rod,XSafety glasses X3 (one for each group member),X250ml beaker,X1 graduated cylinder,X150 grams of Ammonium Nitrate,X100mls of waterSecond Test,X1 thermometer,X1 plastic teaspoon,X1 stop watch,X1 stirring rod,XSafety glasses X3 (one for each group member),X100ml beaker,X1 graduated cylinder,Xleftover from original 150 grams of Ammonium Nitrate,X50mls of waterNOTE: The stirring rod was not used in the First and Second experiments, as it was not available.
A substitute we used the thermometer. MethodsTrial TestIn a 100ml beaker 30mls of water was placed the temperature of the water was recorded. 1 teaspoon of Ammonium Nitrate was added to the water and stirred until dissolved. The temperature was then recorded again.
This was to see the difference between the initial temperature and the final temperature. First TestIn a 250ml beaker place 100mls of water, measure the temperature of the water and record this initial temperature onto a table. Set the timer and add one teaspoon of Ammonium Nitrate to the water, stir this continuously until the Ammonium Nitrate has dissolved. After 1 minute measure the temperature and record it, do this for a further 2 minutes (3 minutes in total).
Repeat this process for a total of 10 teaspoons. Second TestIn a 100ml beaker place 50mls of water, measure the temperature of the water and record this initial temperature onto a table. Set the timer and add one teaspoon of Ammonium Nitrate to the water, stir this continuously until the Ammonium Nitrate has dissolved. After 1 minute measure the temperature and record it, do this for a further 2 minutes (3 minutes in total).
Repeat this process for a total of 10 teaspoons. ConclusionAfter conducting our endothermic experiments we can prove that with less amount of water and an equal amount of Ammonium Nitrate added, the final temperature will be cooler than if we used a larger amount of water. Thus, in theory, if we used a larger amount of water and added more teaspoons it will give the same or similar results. This theory should work if it is done in proportion to the first or second experiment.
