Question

ALL THE INFO YOU NEED IS BELOW

4. What is the solubility product constant Ks for KHT in water? KHT (s) = K+ (aq) + HT-(ag) Ker=[K"] [HT-] [K+ [HT] Initial Change +x Equilibrium

average volume of NaOH: 15.7 mL or 0.0157 L

average number of moles of NaOH added: 6.28*10^-4 moles

molar concentration of [HT] in saturated solution(HT^– acts as a monoprotic acid, reacting with NaOH in a 1:1 ratio (Volume of KHT measured using 25.00 mL volumetric pipet.)): 0.2512 M

Analysis of KHT in water

1. Weigh out 0.8 grams of potassium hydrogen tartrate (KHT) on weighing paper. Add the KHT to a clean dry 400 mL beaker.

2. Measure out 100 mL of deionized water using the graduated cylinder and add to the beaker. Label the beaker KHT in water.

3. Stir the solution mixture with a glass stirring rod for 10 minutes. You now have a saturated solution. There should be some solid KHT that remains undissolved.

4. Gravity filter the saturated KHT solution to remove the undissolved KHT.

a. Obtain a clean dry funnel, a clay triangle, a clean 400 mL beaker, and filter paper.

b. Fold the filter paper as shown in lab lecture, and place it in the funnel, supported over the beaker.

c. Filter out the solids from the KHT solution via gravity filtration by pouring the solution through the filter paper in the funnel. The saturated solution must be clear and colorless after filtration, you will need to filter again if there are solids in your filtrate.

d. Save the filtrate. This is the saturate KHT solution. Label the beaker and cover with a clean piece of paper.

5. Prepare the buret.

a. Pour approximately 75 mL of standard NaOH solution into a clean beaker. Record the exact molar concentration of the standard NaOH solution.

b. Acquire a clean buret, buret clamp, and ring stand.

c. Condition your buret by rinsing two times with two 5 mL portions of standard NaOH solution. Holding the buret in a horizontal position with the stopcock closed and the open end pointing towards a waster beaker, roll the buret such that the NaOH solution wets the inside surface of the buret. Drain the NaOH solution through the buret tip into a waste beaker.

d. After conditioning the buret, add the remaining NaOH solution to the buret.

e. Drain some of the solution through the burette tip into a waste beaker, until the meniscus is at the 0.00 mL graduation mark. Be sure that the tip of the buret is filled with NaOH solution and that there are no air bubbles in the buret tip.

6. Determine the contraction of KHT in the saturate solution, by titrating with 0.04 M standard NaOH solution.

a. Use a clean 25 mL volumetric pipet to transfer 25 mL of filtered KHT solution into a clean 250 mL Erlenmeyer flask.

b. Add 3 drops of phenolphthalein indicator to the flask.

c. Record the initial buret reading to two decimal places.

d. Then place the Erlenmeyer flask containing the 25 mL of saturated KHT solution and phenolphthalein pH indicator underneath the buret.

e. Titrate with NaOH until a faint pink color appears and persistent for at least 30 seconds. Swirl the flask as you are adding the NaOH solution to ensure proper mixing. You can place a piece of white paper under the flask to help aid in visualizing the color change.

f. Record the final buret reading to two decimal places.

7. Repeat Step 6. You will do at least two trials to determine the concentration of KHT in water. If the volumes of NaOH used for these two trials do NOT agree within 1 mL repeat step 6 for a third trial.

Answer 1

Since. Ht reacts with NaOH in a lil ratio [HT-] = 6-2871094x 1000 - 0°0273(M) 7= [K 25

. Kap- (K"] [47] = 0·0273) *= 70453x109