Hydrochlorimetry Lab

During the immersion of the magnesium metal in the hydrochloric acid solution, white bubbles could be seen escaping the surface of the metal as gas was produced during the reaction. Depending on the temperature of the hydrochloric acid and the overall molar concentration, the rate of reaction differed but the same signs were shown. During the reaction between the magnesium metal and higher concentrations of hydrochloric acid, it was observed that the test tube grew quite warm to the touch. As the immersed magnesium strip sank down, it appeared coated in a layer of white bubbles that fizzed like a carbonated drink. In the lower concentrations of hydrochloric acid, the strip spent some time floating at the surface of the solution in the test tube, later sinking down to the bottom as the

gas bubbles serves as evidence that the catalase enzyme is working. As catalase is breaking the

2. In Part 1, why did you not observe a stream of bubbles coming off the stainless steel screw in the sugar solution?

The pre-test helped us decide the exact details of our experiment. We started off with testing 25cm³ of 3-molar hydrochloric acid to 2g of calcium carbonate medium size chips (we decided a medium size chips before we started our pre-test as we had a choice of 3, small, medium, large). We saw that this reacted too quickly as we used 10 second intervals and we couldn't get 6 results this is because our burette could only hold 100cm³ of water, which would make our results reliable. We then decreased the amount of Calcium Carbonate to 1g and kept the same 25cm³ of 3 molar hydrochloric acid and 10 second intervals. We could get the right amount of results of this, so we then tested the other extreme - the lowest molarity.

The mole is a convenient unit for analyzing chemical reactions. Avogadro’s number is equal to the mole. The mass of a mole of any compound or element is the mass in grams that corresponds to the molecular formula, also known as the atomic mass. In this experiment, you will observe the reaction of iron nails with a solution of copper (II) chloride and determine the number of moles involved in the reaction. You will determine the number of moles of copper produced in the reaction of iron and copper (II) chloride, determine the number of moles of iron used up in the reaction of iron and copper (II) chloride, determine the ratio of moles of iron to moles of copper, and determine the number of atoms and formula units involved in

pH was recorded every time 1.00 mL of NaOH was added to beaker. When the amount of NaOH added to the beaker was about 5.00 mL away from the expected end point, NaOH was added very slowly. Approximately 0.20 mL of NaOH was added until the pH made a jump. The pH was recorded until it reached ~12. This was repeated two more times. The pKa of each trial are determined using the graphs made on excel.

8. The Hydrochloric Acid was carefully poured into the beaker with the Sodium Thiosulfate. Once the liquids had made contact, three seconds were waited until the stop watch was started.

Using elemental analysis to determine the percent mass composition of each element in a compound is the first step in creating an empirical formula. There are many different types of elemental analysis, but in this experiment gravitational analysis and Beer’s Law are used. Elemental analysis is first used to find the moles of each element, then converted to mass, and then the percent mass of the element in the product is found (2).

When the zinc was dropped in the hydrochloric acid, the substance began bubbling vigorously, forming a precipitate. Eventually, the zinc dissolved completely. After the lit wooden splint broke the surface of the test tube, there was a loud popping noise. The gas that was released was hydrogen from the acid and the popping noise was a result of the Hydrogen being burned up by the fire creating a small explosion. Two chemical changes occurred in this test: one with the formation of a precipitate (a textbook sign of a chemical change), and the other when the explosion

Place the Elodea in the water, start the stopwatch and measure and record the amount of oxygen bubbles produced by the Elodea over a 5-minute period.

The first brand of bubble gum tested was Bubble Yum. Each of us chewed a piece of Bubble Yum for 3 minutes using a timer. After three minutes, we each blew a bubble. We used a ruler to measure the diameter of the bubble. We did this by holding the ruler from the blower’s mouth to the end of the

3. If a student did not remove all of the bubbles from inside the buret before reading the initial volume and beginning the titration, will this cause the calculated concentration of the hydrochloric acid determined from that trial to be higher or lower than the actual concentration? Explain your answer in complete

There was an increasing trend because the metal was the limiting reactant in this experiment. The amount of each metal placed in the hydrochloric acid was fully used up before the acid was. From Figure 1, it is clear that aluminum produced the most amount of hydrogen gas, then magnesium in the middle and zinc produced the least amount of hydrogen gas. This shows that the same mass of each metal does not produce the same amount of hydrogen gas. Looking at the balanced equations for each of the metals (see lab 2-1, equation 1 and 2), it seems the metals have a similar stoichiometry, however zinc produced a lesser amount of hydrogen gas compared to magnesium because zinc has a higher molar mass than magnesium does. Due to this, more zinc is needed to produce the same amount of hydrogen gas as magnesium. When aluminum and magnesium are compared, it is seen that aluminum and magnesium have similar molar masses, however they have a different stoichiometry (experiment 2-1, equation 1 and 3). Two moles of aluminum react to produce three moles of hydrogen gas, while one mole of magnesium react to produce one mole of hydrogen gas. Based on this stoichiometry, a higher mass of magnesium is needed to produce the same amount of hydrogen gas as

Experimental approach: In the first reaction, copper metal turnings oxidize when put in contact with nitric acid and become copper nitrate.

We used LoggerPro to track the pH changes for 300 seconds, and then repeated the experiment while using H2O in place of Na2CO3. Results: Figure 1 This graph shows the change in pH over time in seconds of Na2CO3 as HCl was titrated into it. Each part of the graph where it becomes flat in a "plateau" shows a section