Exp. Observation of Chemical Changes
Exp 1: Observations of Chemical Changes|Lab Section: 75426|
|Chemicals|Well No.|Observations of the Reaction|
A.|NaHCO3 + HCl|A2|Tiny bubbles formed around the edges. Under white paper it looked transparent, but under black paper there was some white in the middle. |
B.|HCl + BTB|A3|The mixture turned yellow instantly. Under white paper the mixture was more of mustard yellow and under black paper it was less of a bright yellow. |
C.|NH3 + BTB|A4|The mixture is a lighter royal blue under white paper and a darker royal blue under black paper. The mustard yellow would be an acidic indicator and the royal blue a basic indicator. |
D.|HCl + blue dye|A5|The mixture also turned …show more content…
The windex indicated it contained ammonia which is a fairly weak base. Another interesting observation was the toilet bowl cleaner which turned a light blue. The container claimed to contain 9.5% hydrochloric acid which is a mineral acid.
The importance of precision and accuracy played an important role in the experiment. The instructions indicated two drops of the first solution and one of the next. After conducting the experiment I noticed any alteration in the amount of solution put in a mixture could change the concentration significantly. It’s important to be careful when creating a specific mixture.
Overall, the experiment was very informative and fun. I gained a better understanding of chemical reactions as well as acidic and basic properties. The experiments really emphasized how important and useful the mixtures are in creating everyday household items.
Questions and Problems:
A. Suppose a household product label says it contains sodium hydrogen carbonate (sodium bicarbonate, NaHCO3). How would you test this material for the presence of sodium bicarbonate?
I would conduct several test to observe any chemical changes. Like in the experiment the NaHCO3 and HCl produced the tiny bubbles. Another approach is testing color like with bromthymol blue and phenolphthalein to seen any change in color like the yellowish or pink.
B. Looking at the household chemicals you tested with bromthymol blue, what can you deduce from the