Part B of the lab called for greenchemistry; green chemistry manages waste to lower the quantity of waste throughchanging how chemicals can be disposed of for a move towards a green world. Afterpart A was conducted, part B had us take the hydrochloric acid and zincreaction to test the pH level to see if we could dump it in the “sedimentationstation”.
After adding NaOH, the pH monitor was used to see if the reaction wasneutralized. If the pH meter reached 8-9 then it was appropriate to dump intothe provided station. There were sources of errors that arosein this experiment. One source could’ve come from the large difference indiameter, length and mass in sample 10 from the overall class data.
This could bean example of reading something incorrectly or not zeroing out the balancewhich could drastically change the data needed to determine the standards. Anothererror could’ve occurred if all nails reacted to hydrochloric acid at the sametime. It would be difficult to keep a consistent time for all nails; timemanagement is important, because it maintains the accuracy we want for everyreaction. If one nail was left longer than another, that nail could be dissolvingnot only the zinc, but possibly the iron as well.
This could cause the mass,length, diameter and overall appearance to change from what the data calls for.In our lab, each nail was timed independently, but it is unknown if all groupsmaintained the same procedure. The purpose of this lab was todetermine the quality of the zinc coating of the individual nails. Throughthis, the galvanized nails can be compared to two industry standards: thehigher standard being 1 oz. of coating per square foot^3 and the lower standardbeing 0.28 oz.
/ft^2. By using 6M hydrochloric acid on the nails, the zinccoating can be removed then the mass lost (g) can be calculated. In the 5 nailsthat were used in my lab, I found that the average was BLANK g/mm2 andthe overall class average was BLANK g/mm2. Discussion and Conclusions: Amount: 20 mL of NaOH 30 mL of NaOH 40 mL of NaOH 50 mL of NaOH pH level observation Table 3: The results of adding NaOHto the acidic reaction Part B: Mass loss of zinc / surface area After both calculations are found,we can determine the mass loss/mm2:Initial mass – final mass To find the loss of zinc mass (g):h represents the length of each nailA= 2?rh + 2?r2 To find the surface areacalculation:Table2 shows the average of the groups in the lab. Each group entered its averagesfor initial and final mass as well as the length, diameter.
The calculation(below) then determined the mass loss/mm2. 60 nails were tested andthe average surface area for all the nails was BLANK. 1 2 3 4 5 6 7 8 9 10 11 12 Length(mm) 38.2 38.
1 38.2 39 39.1 38.8 38.6 39.1 39 14.34 39.
4 38.4 Diameter(mm) 2 2 2.1 2 1.88 2 2.
08 2.2 2 0.9 1 2 Initial mass(g) 1.2061 1.2102 1.1602 1.195 1.21 1.
1948 1.194 1.183 1.193 1.193 1.203 1.183 Final mass (g) 1.
174 1.109 1.082 1.
110 1.11 1.144 1.
099 1.091 1.100 1.098 1.105 1.098 Mass loss/mm2 Table 2: Averages of the galvanizednails Table1 shows the findings for my group and the observations that were experienced. Trial # 1 2 3 4 5 Length 40 mm 38 mm 38 mm 40 mm 38 mm Diameter 2 mm 2 mm 2 mm 2 mm 2 mm Start time 0.
0 min. 0.0 min.
0.0 min. 0.
0 min. 0.0 min. Stop time 5.00 min.
5.00 min. 5.
00 min. 5.00 min. 5.00 min.
Initial mass (g) 1.196 1.237 1.179 1.201 1.167 Final mass (g) 1.
118 1.320 1.094 1.
107 1.081 observations Bubbles were forming from the bottom to the top, foaming, it was hot to the touch, it had a burnt smell, it had a clear color. Bubbles were forming as well as smoking occurred. It had a burnt smell with a hot touch and a clear color Bubbles were forming and foaming with smoke. It had a burnt smell with a hot touch and a clear color Most bubbles were produced from this one, it smoked a lot with a burnt smell, a hot touch and clear color Bubbles and foam formed with smoke as well as a burnt smell, a hot touch and a clear color Table 1: Galvanized Nails Part A:Results: The first step was to obtain 75 mL of2M NaOH, this compound is known as a base and it will help lower the acidiclevels. In the waste beaker, 20 mL of NaOH was added into the acid reaction;the pH meter was placed into the solution to test the pH level. NaOH was added4 more times at 10 mL each time before it reached a neutralized state. Afterthe observations were recorded, the waste beaker was taken to the”sedimentation station” to be disposed of.
The second part of the experimentinvolved the introduction of waste management and how to dispose of materialsproperly. In this lab, hydrochloric acid and zinc were combined to create an acidicsolution, this was determined by a blue litmus paper which showed the pH to bebelow 7 (acidic). When hydrochloric acid and zinc react with each other, itcauses the zinc to become zinc chloride and hydrochloric acid to becomehydrogen. Zn2++ HCl àZnCl + H.
This reaction is known as single displacement, because one elementreplaces another to form a new element and compound on the product side (Exton).Because the single displacement reaction occurred, the acidic solution neededto be neutralized before it could be disposed of, meaning it cannot go down thedrain or thrown in the trash. The purpose of this lab was to determine if fivedifferent nails met the standard of the industry’s surface area.
This was doneby conducting five trials on five different nails with 6M hydrochloric acid(HCl). First, five nails were obtained, and each nail was measured in length,diameter and mass. The length was measured with a ruler, the diameter wasmeasured with a caliper and the mass was measured with a balance.
The nailswere placed into small, individual test tubes and then completely covered in 6Mhydrochloric acid for approximately five minutes. After doing this, all nailswere retrieved and rinsed off with water via a wash bottle. Each nail had itsmass reweighed and recorded.
The purpose of measuring the initial and finalmass helped us determine the zinc amount by weighing the nail before and afterthe reaction. By doing so, the lab was able to determine if each nail did ordid not meet the standards of the surface area set forth. Methods: The second part of this experimentwill come when its time to dispose of waste.
The lab will learn how to managethe waste to help minimize the waste amount. After the lab is conducted, thewaste will need to be neutralized to help minimize the quantity of waste beingproduced. By doing so, the future of a green world can be helped through greenchemistry which is exactly what chemistry and the lab is aiming to do. In this lab, this experiment will considerthe coating on galvanized nails. Galvanized nails are nails that have beenlayered in a zinc coat to protect the iron of the nail from rusting for aperiod of time(BLANK).
The zinc is used as coating to slow the process ofrusting from occurring, although, this process is inevitable. However, thethicker the zinc coat, the longer the zinc will last. There are two differentcoating methods that exist to allowing the zinc to be applied to the nail. Thefirst method of galvanization is electro-galvanizing (electrolysis).Electrolysis is a coating that is formed by an electroplating process. Althoughit has a clean finish and uniform coating, this process has a low-quality life(BLANK). The second method is known as “hot dipping”, this means that the nailwill be dipped into a molten bath of Zinc to obtain the coat necessary forprotection (BLANK).
This process has a thicker coat and it will acquire ahigher quality of life compared to the first method, but it will have a lessuniform and dull appearance. By having a less uniformed coating applied to thenails, industry standards need to establish the average coating of each nail. Thehighest industry standard for galvanized nails is an average of 1 oz. ofcoating per square foot^3. A slightly lower standard within the industry is0.
28 oz./ft^2 (BLANK). By conducting this experiment, the quality of thecoating on the nail will be exposed to determine its standard. A low standardmeans that the zinc has a low-quality of protection for the nail compared to ahigher standard galvanized nail. Introduction:Title: Lab1: Galvanized Nails