mp4p1Group+2

//**__ Chemical Reactions __**//

Background knowledge:

CaCl 2 is Calcium Chloride. It causes irritation to skin, eyes, and repiratory tract if it is touched. Harmful if swallowed.

NaHCO 3 is Sodium Bicarbonate. Slightly hazardous to skin and eyes.

H 2 O is Water, and is not dangerous.

C 27 H 28 Br 2 O 5  S is Bromothymol Blue. Causes eye irritation, skin irritation. Bad if eaten or inhaled.

Temp.: 20.7 C || to 25.8 C. Partly dissolved || to 29 C, then back down to 27.2 C || Temp. went up to 21.6 C from 17.4 C, makes sizzle sounds || was made. Temp. went up and down. The final temp was 26.4 || Summary Throughout our experiments we saw many changes in our substances. When we mixed dry Calcium Chloride and dry Sodium Bicarbonate, there was no change. The balanced equation for Calcium Chloride and Sodium Bicarbonate is CaCl2 + 2NaHCO3 ---> CaCO3 + 2NaCl + H2o + CO2. Calcium Chloride, Sodium bicarbonate and water had some sort of reaction. The temperature went up a few degrees then went down again. The solid substances dissolved and bubbled in the water. Calcium Chloride and BB reacted and the temperature went up by 8.6 degrees. It went back down 2.7 degrees. The Calcium Chloride dissolved. When we mixed sodium bicarbonate and water, the sodium bicarbonate dissolved and the temperature went down to 18.5 degrees. Water and Calcium Chloride partly dissolved and the temperature went up then down. The Sodium Bicarbonate, Calcium Chloride, and BB had the most noticeable reaction. The mixture turned white, bubbled to the point of overflowing, started making “sizzling” noises. The temperature went up from 17.4 to 21.6. Last, we mixed Sodium Bicarbonate and BB. The Sodium Bicarbonate dissolved in the BB and the temperature went down to 19.1.
 * **__Combination__** || **__Prediction__** || **__Observation__** ||
 * CaCl 2 + NaHCO 3 || Create a Gas || Nothing happened
 * CaCl 2 + H 2 O || Fire || Temp. wentup to 26.5 C then down
 * <span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif;">CaCl 2 + Bromothymol Blue || <span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif;">Calcium chloride dissolve into BB. Fire? || <span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif;">Dissolved. Temp. went up by 8.6 C
 * <span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif;">CaCl 2 + BB + NaHCO 3 || <span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif;">Form precipitate || <span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif;">Turned white, bubbled to the top.
 * <span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif;">CaCl 2 + H 2 O + NaHCO 3 || <span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif;">Fire || <span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif;">Made bubbles, indicates a gas
 * <span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif;">NaHCO 3 + BB || <span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif;">Change color || <span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif;">BB got a little lighter. Temp: 19.1 C ||
 * <span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif;">NaHCO 3 + H 2 O || <span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif;">Dissolve || <span style="color: #00ff00; font-family: 'Arial Black',Gadget,sans-serif;">Dissolved. Down to 18.5 C ||

Conclusion : Calcium Chloride + Sodium Bicarbonate + water ended in a chemical reaction. The temperature went up then down and both solids dissolved while it bubbled. A chemical reaction was shown in our experiments by either forming a precipitate, bubbling, dissolving the solids into a new substance, or the temperature changed. 6 out of the 7 experiments had a temperature change. 5 of the 6 temperature went up and 1 went down. This could be a sign of and exothermic reaction. The one that had a lowering of temperature could have been an endothermic reaction. 1 of the 7 experiments had a color change. The calcium chloride, bromothymol blue, and sodium bicarbonate had a white color change. This could be a sign of a chemical reaction. After sitting for the weekend there was a new substance that did not dissolve in water was formed.

May 3, 2012 Balancing Equations

How does the mass of the reactants compare to the mass of the products in a chemical reaction when a precipitate is formed? Hypothesis: It will stay the same. Independent Variable: Mass of the reactant in grams Dependent Variable: Mass of the products in grams Observations: Opaque= suspension

Yellow precipiate

Balancing the Equation Pb(NO3)2 + NaI PbI2+NaNO3 NaI NaNO3 Pb(NO3)2 + 2NaI PbI2+2NaNO3
 * Lab Group || Mass of the Glassware || Mass of the reactants and Glassware || Mass of the reactants Alone || Mass of the Products and Glassware || Mass of the Products Alone || Change in Mass ||
 * 1 || 90.5 || 95.1 || 4.6 || 95.1 || 4.6 || 0 ||
 * 2 || 96.1 || 98.2 || 2.1 || 98.2 || 2.1 || 0 ||
 * 3 || 80.2 || 87,2 || 7 || 87.2 || 7 || 0 ||
 * 4 || 81.7 || 86.8 || 5.1 || 86.8 || 5.1 || 0 ||
 * 5 || 74.2 || 76.4 || 2.2 || 76.4 || 2.2 || 0 ||
 * 6 || 92.9 || 96.8 || 3.9 || 96.8 || 3.9 || 0 ||
 * 7 || 88.5 || 93.1 || 4.6 || 93.1 || 4.6 || 0 ||