Mrs. Haire
IB Chemistry
Experiment 6
Mole Ratio in a Chemical Reaction
Background:
Mole ratios of reactants are often times figured out by the use of the other products in a chemical equation. However, in the instance that the products’ mole ratios are unknown, it can be determined through the experiment. This method is called continuous variations.
In this lab, I determined the mole ratio between Sodium Hypochlorite and Sodium Thiosulfate by using continuous variations of ratios in a given volume. This reaction was exothermic so I measured the heat that was produced from the reaction.
Hypothesis:
The reaction with the proper mole ratio will reach the highest temperature and this is due to the reaction being balanced and …show more content…
Variables: Independent Variable: Ratio of reactants Dependent Variable: Temperature change Controlled Variable: Total number of moles of reactants
Apparatus:
Protective Goggles Thermometer Graduated Cylinder Sodium Hypochlorite (NaClO), solution Calorimeter Sodium thiosulfate (Na2S2O3), solution Distilled Water pipettes
Method:
It is important to wear protective goggles and gloves at all time, because these chemicals can cause damage if they come in contact with your skins or eyes. 1. Acquire a beaker that contains NaClO solution and another beaker with Na2S2O3. 2. Measure the temperature of both the NaClO solution and the Na2S2O3 and record the data 3. Measure out 5.0 mL of NaClO and then pour it into the calorimeter 4. Measure out 45.0 mL of Na2S2O3 and pour it into the calorimeter quickly closing the lid to reduce heat …show more content…
Stir the contents of the calorimeter with the temperature gently and record the highest temperature of the mixture in the data table. 6. Pour the solution into the sink and rinse, and dry the calorimeter and the thermometer to eliminate leftover solution from previous trial. 7. Repeat these steps 2-5 times with a different ratio of solution, keeping to total volume at 50 mL 8. Continue testing the various ratios until the maximum temperature if found.
Data:
Initial Temperature of NaClO: 23.9 oC Na2S2O3: 23.8 oC Volume of NaClO(mL) | Volume of Na2S2O3(mL) | Max Temperature(oC) | 5.0 | 45.0 | 27.0 | 10.0 | 40.0 | 29.0 | 20.0 | 30.0 | 35.5