Recrystallization - Study guides, Class notes & Summaries

In the experiment, you added water to the reaction vessel after the reaction was complete, but we did not discuss why. Based on what happened after adding the water, which of the following is the reason for the addition of water? a) lower the solubility of the product in solution so it precipitated out b) increase the solubility of the product in solution so it precipitated out c) lower the solubility of the product in solution so it stayed in solution d) increase the solubility of the pr...

©FYNDLAY 2024/2025 ALL RIGHTS RESERVED 11:08AM. A+ 1 Chemistry 235 Lab Final Pre and Post Exam Questions And Answers |Latest 2025 | Guaranteed Pass. Exp. 1 define the melting point of a substance. - Answerit is the temperature at which a solid becomes a liquid. Exp. 1 why should you always use a new capillary tube when performing a second melting point determination on your sample? - Answerto keep the sample from getting impurities Exp. 1 why is it necessary to allow the Mel-Temp to co...

CHEM 231 Lab Final Exam with Questions and Answers When doing a mixed melting point determination why is it important to carefully mixed together the unknown sample with the known sample? ANSWER It is important to mix the unknown sample with the known sample because we can tell if the mixture is pure or impure when melting the sample and comparing the melting points to one another to determine the unknown What is the meaning of a sharp melting point? What is the significance of a sharp mel...

What does MgSO4 do when added to solution? correct answers It removes water that is dissolved in the solution Why is it more difficult to remove DMSO from a reaction mixture correct answers It has a very high boiling point (90% sure this is correct, but may be wrong) During recrystallization, what will happen if too much hot solvent is used to dissolve the crude compound? correct answers few or zero crystals will be isolated Why is it important to cover the reaction mixture during stirr...

Earth Science Final Exam Questions With Correct Answers Latest 2024/2025 | Graded A+. The closer isolines are... - ANSWER the steeper the gradient (diagram: North side is steepest) 3. The altitude of Polaris equals... - ANSWER the latitude of the observer Diagram: Observer's altitude = 66.5 degrees North 4. The Earth rotates - ANSWER West to east 15 degrees per hour in 24 hours or one day 5. Latitude lines run Longitude lines run - ANSWER east-west, but measure north or south of the equ...

Separation by liquid-liquid extraction is based on a) compound's dielectric constant in 2 dif solvents b) # of theoretical plates in the separation c) use of phase transfer catalysts d) difference in boiling points of 2 liquids e) distribution of a compound between 2 immiscible phases - e) Distribution of a compound between two immiscible phases. Preparative gas chromatography is often chosen over distillation as a means of separation because gas chromatography a) is relatively inexpen...

Abrasives - ANSWER-A material made of hard, sharp particles used for cutting chips from a workpiece surface. They are often used in finishing operations that clean, polish, or otherwise prepare the surface of a part. Aluminum Oxide - ANSWER-A chemical compound of aluminum and oxygen that is used as a conventional abrasive. It is extremely durable. Atom - ANSWER-The smallest unit of an element. It consists of protons and neutrons in a center nucleus and orbiting electrons. Carbon Fiber -...

CWB Welding Inspector Level III Study Guide Questions and Verified Answers_ 100% Correct_ Graded A Which of the following elements is often present in submerged arc fluxes to improve arc stability? (a) copper (b) potassium (c) nickel (d) tungsten - ANSWER -(b) Thoria is added to tunsten electrodes for what purpose? - ANSWER -To increase thermionic emission by lowering the work function. True or False? All pure metals have the same crystal structure. - ANSWER -False. Metals gene...

Earth Science Final Exam Questions and Answers Latest Updated 2024/2025 Graded A+. The same objects have the - ANSWER same density (NO MATTER WHAT SIZE) 2. The closer isolines are... - ANSWER the steeper the gradient (diagram: North side is steepest) 3. The altitude of Polaris equals... - ANSWER the latitude of the observer Diagram: Observer's altitude = 66.5 degrees North 4. The Earth rotates - ANSWER West to east 15 degrees per hour in 24 hours or one day 5. Latitude lines run Longit...

CWB | Welding Metallurgy 2 Prep Test Questions & Verified Solutions| Latest Update Heat affected zone - ANSWER The HAZ is the zone of the base metal that has been heated to high temperatures just below its melting point during the welding process ZONE 1 - ANSWER zone 1 represents metal that has been heated to temperatures in excess which will give a structure that is coarse grained. This large grain structures is due to grain growth at this temperature. ZONE 2 - ANSWER zone 2 ...