Question

PH Study Prelab Questions Name Section 1. The pH of three solutions of 0.10 M HCN. HE and HOBr are 5.1.2.1 and 4.7 respectively. Designate which is the strongest and which is the weakest acid. 2. The pH of seawater is 8.30. What is the concentration (molarity) of (H.O'l in seawater 3. Predict whether reaction of each of the following compounds with water will produce an acidic, basic, or neutral solution. Use the information in the introduction to this experiment and in Table 1 to make these determinations NHCI Na, CO CuSO NaCl KNO, LiF 4. Briefly summarize the steps necessary for the proper care of a pH electrode (refer to Appendix E).

Answer 1

1) low.ph means more acidic. So HF is strongest acid and HCN is weakest acid.

2) answer in the image uploaded.

3) acidic

Basic

Neutral

Neutral

Neutral

Neutral

4) given in image uploaded
:3 - - 647 + -8,3 10 4T +OHO H₂O - 1,83 x Kw = [010] CH+] 10th = x (1083) x² + 7084-10-0 8.3 x = 0,92x15t 108 40,97x107 -8.3 (H = 10. 2471-8 = pH. - Loy (10,2x108) = 6.99

Step 1: Remove the protective cap or rubber boot from the bottom of the sensor and rinse the electrode with distilled or deionised water. Step 2: Place the electrode in a beaker containing one of the liquids that are listed below, in order of ionic ability, to condition the electrode. Soak the electrode for 20 minutes. • 3.8 M or 4.0 M KCI • 4.0 pH buffer • 7.0 pH buffer Once the conditioning is done, rinse the electrode with distilled or deionised water. Remember to never condition a pH electrode in distilled or deionised water for a long time as prolonged exposure to

Once the conditioning is done, rinse the electrode with distilled or deionised water. Remember to never condition a pH electrode in distilled or deionised water for a long time as prolonged exposure to pure water damages the special glass membrane. After conditioning, the electrodes are ready for instrument calibration and to measure pH.