mp4p3Group+3

  - 



Chemical Reactions Lab

Background Information:

Calcium Chloride- CaCl2- A salt that is a solid at room temperature. It is not sanitary to have CaCl2 on your skin. The substance is typically used for brine, to refrigerate plants, and for dust and ice control on roads. Since Calcium Chloride is soluble, it can be used for displacing ions from a solution. When calcium chloride is used in food (safe) it is usually in canned vegetables.

Sodium Bicarbonate- NaHCO3- Baking Soda- Other known as sodium hydrogen carbonate is a white solid that typically appears as a fine powder. This substance is mostly used in baking. NaHCO3 is made by using the Solvay process, which are sodium chloride, ammonia, carbon dioxide and water in a reaction.

Bromothymol Blue- C27H28Br205S- BTB- a chemical indicator for weak acids and bases. Also used for observing photosynthesis activity. When in an acidic solution, the substance will turns yellow. It is bluish green in a neutral solution. This substance is used mostly for measuring other substances with relatively low acidic or basic levels.

Water- H2O- a liquid molecule that contains one oxygen and two hydrogen. They are connected by covalent bonds. Water covers 70.9% of the Earth. Safe drinking water is essential for humans and other life.

Pictures of our Lab

The chemicals we were using were Calcium Chloride and In this photo, our group is observing a chemical change. Water. The starting temperature was 20.6 * C. We were observing the CaCl2+H2O dissolve, settle out (which is precipitate), get cloudy and changing color. The final temperature was 23.8 * C.

Summary Our lab was a success. We achieved accuracy and most of our predictions were true. For this experiment, we got a lot of reactions. Our first trial was water, Sodium Bicarbonate and Calcium Chloride. Together, they produced gas bubbles, color change, precipitate, lower temperature and fizzing within the combined substances. Our next trial wasn’t much similar. We used 15 milliliters of Bromothymol Blue and Calcium Chloride. Instead of precipitate and lowered temperature, we observed dissolving and higher temperature. We observed many chemical reactions during our lab and learned a lot about them. The signs of chemical reactions can be precipitate, formation of gas, color change, gas bubbles, temperature change, odor and endothermic or exothermic energy. This lab has given us much more knowledge about labs. Questions: What are signs of a chemical reaction Independent variable: Combination of chemicals in a test tube Dependent variable: signs of a chemical reaction Hypothesis:
 * Combination || Prediction ||
 * Calcium chloride + sodium bicarbonate || nothing ||
 * Calcium chloride + sodium bicarbonate + water || Precipitate and gas bubbles ||
 * Calcium chloride + water || Color and gas bubbles ||
 * Sodium bicarbonate + water || <span style="font-family: 'Times New Roman',serif;">gas bubble, color, and temperatures ||
 * <span style="font-family: 'Times New Roman',serif;">Bromothymol Blue + Calcium chloride || <span style="font-family: 'Times New Roman',serif;">Precipitate and color ||
 * <span style="font-family: 'Times New Roman',serif;">Bromothymol Blue + sodium bicarbonate || <span style="font-family: 'Times New Roman',serif;">Color change and gas bubble ||
 * <span style="font-family: 'Times New Roman',serif;">Bromothymol Blue + sodium bicarbonate + Calcium Chloride || <span style="font-family: 'Times New Roman',serif;">Odor, color, gas bubbles, temperature ||

Experiment 1: Sodium Bicarbonate + Calcium Chloride

Observation- When combined the subject did not show any signs of a chemical change

Experiment 2: Sodium Bicarbonate + Calcium Chloride + Water

Water starting temperature: 20.25°C

Observation- gas bubbles, fizz, white, precipitate, opaque

Final temperature: 19.1°C

Experiment 3: Bromothymol Blue + Calcium Chloride

Starting temperature: 20.8°C

Observations- dissolving, warmer, color change

Final temperature: 24.2°C

Experiment 4: Bromothymol blue + Calcium Chloride

Starting temperature: 20.8°C

Observation- color change, dissolve, colder

Final temperature: 20.4°C

Experiment 5: Sodium Bicarbonate + Bromothymol Blue + Calcium Chloride

Starting temperature: 21.1°C

Observation- color change, precipitate, gas bubbles, fizzing, odor

Final temperature: 20.6 °C

Experiment 6: water + Calcium Chloride

Starting temperature: 20.6°C

Observation- color change, precipitate

Final temperature: 23.8°C