Group+3

CHEMICAL REACTION 3 -
=Investigating the Mass of Solid Products as a Result of Concentration of Reactants.=

Research Question:
How does the concentration of reactants in our chemical reaction (Sodium Hydroxide and Copper Sulfate) affect the amount of solid product formed (Copper Hydroxide).

**Hypothesis:**
As the concentration of the reactants increases, the amount of solid product that is formed will increase as well. When a substance is diluted (ex: Copper Sulfate), the amount of Copper Sulfate molecules in the mixture goes down even though the volume stays the same (the remaining volume is taken up by the water molecules). Therefore, the smaller the amount of Copper Sulfate molecules, the less molecules will react when the mixture is combined with Sodium Hydroxide. And so, as less molecules react, the mass of the solid product produced goes down.

Independent variable -
The independent variables of this experiment were the concentrations of both the Sodium Hydroxide and Copper Sulfate used for the chemical reaction trials The different concentrations were 1M, 0.66M, 0.5M, 0.33M, and 0.1M.

Dependent variable -
The dependent variable of this experiment was the mass of the solid products (Copper Hydroxide) produced by the chemical reaction between Sodium Hydroxide and Copper Sulfate.

Controlled variables-
The controlled variables for this experiment were: The volume (30 mL) of Copper Sulfate and Sodium Hydroxide used as reactants in the chemical reaction; The time allowed for the chemical reactions to take place (1 minute); and the weight of each piece of filter paper.

**Materials:**

 * Sodium Hydroxide 1mL
 * Copper Sulphate 1mL
 * 140mL Beakers (X2)
 * Beral pipets (X2)
 * Filter Paper (X5)
 * Funnels (X2)
 * Electronic Scale
 * Distilled Water
 * Stopwatch
 * Graduated Cylinders (X3)
 * Erlenmeyer Flasks (X2)
 * Paper Towels

TRIAL 1
1. Measure 30 mL of Copper Sulfate into a 140 mL beaker. 2. Measure 30 mL of Sodium hydroxide in a graduated cylinder. 3. Fold the circular piece of filter paper into fourths and fit into the funnel so it forms a strainer. Add a few drops of distilled water as necessary to keep the filter paper stuck to the funnel. 4. Measure the weight of the filter paper and the drops of water on an electronic scale. 5. Place the funnel on top of Erlenmeyer flask. 6. Pour the 1mL Sodium Hydroxide into the 140 mL beaker with the 1mL Copper Sulfate. 7. Let the reactants react for 1 minute (use stopwatch). 8. Pour the products of the reaction into the funnel. 9. Let the aqueous substances produced from the reaction precipitate into the Erlenmeyer flask. 10. When the aqueous substances are almost completely drained, take the filter paper and remaining solid out of the funnel and put it on a paper towel. 11. Label the paper towels with the ratio of the amount of reactants to distilled water. (for later reference) 12. Move the paper towels to the side to let the solid product dry overnight.

[[image:05-11-07_1109.jpg width="275" height="206" align="left" caption="0.1M Copper Hydroxide"]]TRIAL 2
11. Measure 3 mL of Copper Sulfate and 27 mL of water. 13. Combine the water and the Copper Sulfate in a 140 beaker. (9 parts water and 1 part Copper Sulfate). 14. Measure 3 mL of Sodium Hydroxide and 27 mL of water. 15. Combine the water and Sodium Hydroxide in a graduated cylinder. (9 parts water and 1 part Sodium Hydroxide). 16. Repeat steps 3-5. (Prepare the Filter) 17. Pour the 0.1mL Sodium Hydroxide into the 140 beaker with the 0.1mL Copper Sulfate and let them react for 1 minute. 18. Repeat steps 8-12. (Remove from Filter)

TRIAL 3[[image:05-11-07_1110.jpg width="285" height="215" align="right" caption="0.33M Copper Hydroxide"]]
19. Measure 10 mL of Copper Sulfate and 20 mL of distilled water. 20. Combine the distilled water and Copper Sulfate into a 140 mL beaker. (2 parts water and 1 part Copper Sulfate) 21. Measure 10 mL of Sodium Hydroxide and 20 mL of water. 22. Combine the distilled water and Sodium Hydroxide in a graduated cylinder. (2 parts water and 1 part Copper Sulfate) 23. Repeat steps 3-5. (Prepare the Filter) 24. Pour the 0.33M Sodium Hydroxide in the 140 mL beaker with the 0.33M Copper Sulfate and let them react for 1 minute. 25. Repeat steps 8-12. (Remove from Filter)

TRIAL 4
26. Measure 15 mL of Copper Sulfate and 15 mL of distilled water. 27. Combine the distilled water and Copper Sulfate into a 140 mL beaker. (1 part water and 1 part Copper Sulfate) 28. Measure 15 mL of Sodium Hydroxide and 15 mL of water. 29. Combine the distilled water and Sodium Hydroxide in a graduated cylinder. (1 part water and 1 part Sodium Hydroxide) 30. Repeat steps 3-5. (Prepare the Filter) 31. Pour the 0.5M Sodium Hydroxide into the 140 mL beaker with the 0.5M Copper Sulfat and let them react for 1 minute. 32. Repeat steps 8-12. (Remove from Filter)

TRIAL 5[[image:05-11-07_1112.jpg width="288" height="216" align="right" caption="0.66M Copper Hydroxide"]]
33. Measure 20 mL of Copper Sulfate and 10 mL of distilled water. 34. Combine the distilled water and Copper Sulfate into a 140 mL beaker. (1 part water and 2 parts Copper Sulfate) 35. Measure 20 mL of Sodium Hydroxide and 10 mL of distilled water. 36. Combine the distilled water and Sodium Hydroxide in a graduated cylinder. (1 part water and 2 parts Sodium Hydroxide) 37. Repeat Steps 3-5. (Prepare the Filter) 38. Pour the 0.66M Sodium Hydroxide into the 140 mL beaker with the 0.66M Copper Sulfate and let them react for 1 minute. 39. Repeat steps 8-12. (Remove from Filter)

THE NEXT DAY
40. After the solids have dried on the filter paper overnight, remove them from the paper towels and mass (weigh) them using an electronic balance. 41. Record the mass (weight) of each sample, subtracting the weight of the filter paper recorded in step 4. 42. Compare the mass of each sample to their concentrations and how the amount of distilled water added into the reactants affected the mass of the solid produced. 43. Record data.

Qualitative Observations:
As the 30mL of Copper Hydroxide was poured into the 30mL of Sodium Hydroxide a number of things took place. First, as soon as the Copper Sulfate touched the Sodium Hydroxide, chemical reactions started taking place and inside the beaker formed the blue tissue-looking solid, Copper Hydroxide. The remaining aqueous solution shimmered a bit and then settled, it was still clear however. When the products of the chemical reaction were strained through the funnel, it was clear that the more concentrated the two reactants were, the more solid Copper Hydroxide was produced. In the beaker, the Copper Hydroxide had a tissue-like quality that made it look stringy, however, once it was strained and laid out to dry, it was clumpy and looked almost powder-like.

Quantitative Observations:
Filter Paper weighs 0.83 grams. Mass of 1M Coper Hydroxide solid: 3.95g - 0.83g = 3.12 grams Mass of 0.66M Copper Hydroxide solid: 2.58g - 0.83g = 1.75 grams Mass of 0.5M Copper Hydroxide solid: 2.55g - 0.83g = 1.72 grams Mass of 0.33M Copper Hydroxide solid: 2.11g - 0.83g = 1.28 grams Mass of 0.1M Copper Hydroxide solid: 1.50g - 0.83g = 0.67 grams



**Data Processing:**
As the concentration of the 2 reactants increases, the mass of the solid product increases.

Conclusion:
The hypothesis presented at the beginning of our experiment proved as correct. As the concentration of the reactants increased, the amount of solid product produced increases. Like it was explained in the hypothesis, diluting the reactants added water molecules into the mixtures and lessened the amount of Copper Sulfate and Sodium Hydroxide molecules. With less Copper Sulfate and Sodium Hydroxide molecules the amount of individual reactions decreases. With less reactions taking place, the amount of solid product produced (Copper Hydroxide) decreases. All of the results from the expiriment followed what the hypothesis said except for the .66M reactants. The mass of the solid product produce was still more that the .5M reactants but it doesn't necessarily follow the line of best fit.

Evaluation:
Overall, the experiment was successful, but not entirely accurate. The general idea of the hypothesis was proven to be true, however, the experiment wasn't entirely mistake-free. For example, some of the solid could have leaked through the funnel during the precipitation stage as a result of poor filter placement. An example of this was the .66M reactants. This point on the graph above does not follow the line of best fit, most likely because of this error. The measurement of the solid product could have been more accurate if the filter paper had been placed more carefully in the funnel. More trials of the experiment could have also been done to insure that as many points as possible are on or close to the line of best fit. Another question that could be asked is how the concentration of the reactants in this same experiment will affect the amount of aqueous sodium hydroxide produced by the chemical reaction.