Chemical Proportionality

Chemical Proportionality (Carbonate and Hydrochloric Acid)
Introduction:
The purpose of this experiment is what happens when a solid substance, a metal carbonate is added slowly to a solution of an acid. We are finding methods of determining acid concentration. For us to balance certain equations, we will use a stoichiometry. For this experiment, we will need to set up the ratio and finding the concentration of HCI.
Procedure:
• Grab 4 different beakers.
• Add a small amount of sodium carbonate onto a weighted beaker.
• For each beaker pour 10 mL, 15 mL, 20 mL, and 30 mL of solution A.
• Add a drop or 2 of indicator to each beaker. The indicator should be Phenolphthalein.
• Slowly add small amount of sodium carbonate to each one until it
• Repeat the first 6 step but use solution B instead of A.
• Repeat the process again but use solution C.
• For solution D, measure out 25.0 mL of the unknown solution and add a drop or two of the indicator.
• Slowly add small amount of sodium carbonate until it changes color.
• Measure out the initial and remaining mass of Na2CO3 of solution D.
Data/Table
HCI 0.5M
Vol HC sol A Remaining mass of Na2CO3 HCI 0.25M
Vol B Remaining
Mass of Na2CO3 HCI 0.3M
Vol C Remaining
Mass of Na2CO3 HCI unknown
Vol D Remaining
Mass of Na2CO3
10 mL 0.28 g 10 mL 0.23 g 10 mL 0.21 g 25 mL 0.72g
15 mL 0.49 g 15 mL 0.42 g 15 mL 0.32 g
20 mL 0.60 g 20 mL 0.49 g 20 mL 0.46 g
30 mL 0.90 g 30 mL 0.67 g 30 mL 0.65 g
For solution A, the mass to volume ratio within the highest average was 2.67g/L apart. Solution B had 1 that was 4g/L apart from the average while the rest were 2g/L apart from the average. Solution C had the most accurate within the average because the highest apart from the average was only 0.3g/L. I would say that for each solution the mass-to-volume ratios agree with one another.
2. For solution A, the slope of the line was y = 30.114x + 0.0029 and the average mass-to-volume ratio was 30.17. Solution B’s slope was y = 20.857x + 0.0614 and the average mass-to-volume ratio was 24.46. Solution C’s slope was y = 22.171x - 0.0057 and the average mass-to-volume ratio was 21.75. Solution A and C’s slope and average was relatively close within each other while Solution B was 3.353 away and wasn’t as accurate as Solution A and C.
3. The most concentrated to least of our solution is Solution A with 30 g/L next is Solution B with 24 g/L and lastly with Solution C with 22 g/L. The relative ratios of the concentrations of the solutions made Solution A at most concentrated and Solution B at least concentrated. Our experimental result with the relative ratios of the concentrations calculated using the concentration of the acids did not compare with each other because of the outlier in Solution B we had. If we didn’t have this outlier, our data would have supported the accepted