d each description in the first column of the table below. If any chemical element with atomic number of 92 or less matches the description, check Yes and er the chemical symbol of an element that matches. Otherwise check No in the second column. description An element in Period 2 and Group 8A. A metal in Group 7A. A noble gas with a higher atomic number than thallium. A transition element in Period 4. Does any element with Z ≤ 92 match the description? Yes Yes Yes Yes No No No No If you checked yes, give the symbol of an element with Z ≤ 92 that matches. 0 X 0 0 S

1. Discuss the appearance and use of each pipette.         a. Ostwald folin pipette         b.  Volumetric pipette         c. Mohr pipette

1. What is happened if we add gypsum to drilling mud and why ? 2. What is happened if we add ligno and caustic to drilling mud and why ?

mixing instead of vigorously shaking them will help prevent emulsions from forming in the first place. 1. Questions 1. You are given a substance that is equally soluble in water and hexane (two immiscible solvents). a) What is K? b) If you start with 10 g of the substance dissolved in 100 mL of water and are given 100 mL of hexane to extract with, algebraically show that it is better to do two smaller extractions using 50 mL of hexane for each extraction than it is to do one extraction using 100 mL o hexane. 2. You have a solution that contains 4.0 g of oxalic acid dissolved in 100 mL of water. This solution is placed in a separatory funnel, and then 100 mL of diethyl ether is added to the separatory funnel and an extraction is performed. (Diethyl ether and water are immiscible solvents.) Use the following constants to calculate how much oxalic acid is in each solvent after the extraction. Solubility of oxalic acid in water = 9.5 g / 100 mL Solubility of oxalic acid in ether = 16.9 g /…

Select one for each box

Answer in not more than 5 sentences per question 1. Discuss the a) direct method of weighing b) indirect weighing using the analytical balance. 2. Explain how suction filtration is carried out in the laboratory. Give the important points that must be observed in doing the process. 3. Explain why it is important to wash the precipitate. Can distilled water be used to wash all types of precipitates? 4. Discuss how to use a desiccator. When should a desiccant be replaced? Give 2 examples of substances used as desiccants.

Identification Complete each statement. Write your answer at the end of each question. 92. To determine the gram-milliequivalent weight, molecular weight of the analyte is divided by 93. It is carried out by dissolving the substance under examination in an accurately measured quantity of standard solution known to be in excess and tittrating the excess of the latter with another standard solution. 94. This method of standardization is accomplished by making use of a standard solution. A