A cuvette block, four cuvettes, three 50 mL beakers, one 150 mL beaker, and one 5mL pipet were obtained. The phosphate buffers NaH₂PO₄ and Na₂HPO₄ were procured weighing .4060g and .4106g respectively. The phosphate buffers were then transported to the 150mL beaker. Next 50mL of distilled water was measured using a graduated cylinder and added to the 150mL beaker. Twenty drops of bromothymol blue was also added to the 150mL beaker.
Next, obtain a 5 mL serological pipet and thoroughly rinse it with the buffer solution, then discard the buffer solution into the 250 mL beaker. Now, use the pipet to distribute 5 mL of the buffer solution into three 50 mL beakers. Be sure that the 50 mL beakers have been cleaned are dried prior to this. Next, locate the three pre filled burets in the lab room. Find the buret labeled 1.0M HCl and add exactly 1.00 mL of HCl to just one of the three 50 mL beakers with buffer solution already in them.
Procedure Step 1, Obtain acid, in a 100 ml Erlenmeyer flask add 35 ml of .2M HCl solution. Step 2, add an indicator to the acid, select the flask and add 2 drops of phenolphthalein indicator. Step 3, Fill buret with NaOH, obtain a 50 ml buret and fill with .2M NaOH solution.Step 4, Titrate NaOH into HCl until end point, record initial buret volume and add NaOH (quickly at first then slowly) until the HCl solution turns pink and record the final buret volume of NaOH in buret. Step 5, repeat steps 1-4 using pH meters, add a pH meter to the acid solution. Record several points of pH and NaOH added (especially near equivalence point) to be use later to prepare a titration curve.
Materials & Methods Identifying the unknown compound solution (#2314) first required the identification of each individual solution. One drop of each solution was added to five individual wells of a spot plate. Next, three drops of 3M hydrochloric acid (to be referred to from now on as HCl). The spot plate was then cleaned, and the procedure above was recreated two more times, the second test done by adding 3M ammonium hydroxide (NH4OH), and the third by adding 1 drop of dimethylglyoxime (DMG). All color observations were recorded and compared to the known behaviors of the focus metals.
Calculate the equilibrium constant, Ke. [0.85] 4. If the equilibrium concentration of F2(g) is 1.50 mol/L and H2(g) is 2.5 mol/L, determine the concentration of HF(g) at equilibrium. [1.92 mol/L] F2 (g) + H2 (g) === 2 HF(g) Ke = 0.98 5. If 0.100 mol of hydrogen iodide is placed in a 1.0 L container and allowed to reach equilibrium, find the concentrations of all reactants and products at equilibrium.
Approximately 20 drops of a .04% Bromothymol blue solution was then added to the beaker of the phosphate buffer. Using a clean 5 mL serological pipette, transfer 5 mL of the phosphate buffer and Bromothymol blue solution to each of three clean 150 mL beakers. Next, using the buret for HCl, add 1 mL of HCl to one of the three beakers, then label this beaker “Yellow”. Next use the buret for NaOH and add 1 mL of NaOH to another of the three beakers, and label this beaker “Blue”. Lastly add 1 mL of water using the buret for water to the last beaker, and label this beaker “Green”.
SYNTHESIS 3 Purifying an unknown solid by recrystallization involved preparing cobalt amine chloride product. By adding five grams of cobalt II chloride into 20ml of 9M HBR in 250 mL beaker, plus 15 mL of deionized water. Dissolving the compound within pure water, filtration by gravity and adding two grams of activated charcoal and 25 mL of concentrated. Cooled after heating and additional six mL of 30 percent hydrogen peroxide. Filter by suction then collect the dark solid.
Materials and Methods Part 1 For the cation elimination test first 10 drops of potassium, iron (III), zinc (II), copper (II), and cobalt (II) were added to 5 centrifuge tubes and the color was recorded. Then for the metal hydroxide test, 6 M NaOH was added drop wise till a precipitate was formed. Each solution except potassium formed a precipitate, so then 10 additional drops of NaOH were added to the remaining solutions. Tubes were cleaned with distilled water and 6 M HCL. Next was the ammonia test 10 drops of each metal solution were added to new centrifuge tubes and 15 M NH4OH was added until the solution changed color or a precipitate was formed.
Next, 50 mL of distilled was placed into the 150 mL. Twenty drops of Bromothymol blue were added to the 150 mL beaker solution. The pH was then recorded. Five mL of this solution was transferred into three separate 100 mL beakers. In one of these beakers, 1 mL of HCl was added to the solution, making this the “Yellow” beaker.
5.04H: Gas Stoichiometry Lab Worksheet Name: _________________________ Data and Observations: Present all relevant data in a data table below. Include an observations section for any observations that you made during the lab. (5 points) Data Table| Mass of magnesium strip (grams)|0.0304g| Volume of gas collected (mL)|10ml| Barometric pressure (atm)|1.1| Room Temperature (°C)|21 | Vapor pressure of the water (torr)|18.7| Calculations: 1. Write the balanced equation for the reaction conducted in this lab, including appropriate phase symbols. (2 points) Mg(s) + 2 HCl(aq) → H2(g) + MgCl2(aq) 2.