Recrystallization - Study guides, Class notes & Summaries

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...

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 -...

Recapitalization a technique used to purify organic solid compounds with the goal to dissolve and subsequently crystallize a pure substance from the solution. What are the four characteristics of a good solvent? -Target must be soluble in high temp with impurities soluble at room temp or at high temps -Must be chemically inert (non-reactive) -Low boiling point, or highly volatile What are the 5 basic steps to Recrystallization -Choose suitable solvent -Dissolve the impure mixture in the...

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 ...

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...

CHEM 335 - Exam 1 Questions and Answers Latest Update Already Passed Pure Substance - Answers a homogenous sample consisting of molecules of having the same structure Effects of impurities - Answers - inhibit chemical reactions - catalyze undesirable side reactions - invalidate chemical test results The Recrystallization Process - Answers 1) Impure solid is dissolved in minimum amount of suitable solvent at its boiling point -- to form a saturated hot solution 2) When the hot saturated s...

CWB Level 3 Module 20 Practice questions Which of the following metals has the highest thermal conductivity? C (a) carbon steel (b) stainless steel ( (c) aluminum - correct answer (c) aluminum The Ellingham diagram C (a) is a plot of thermal conductivity against temperature. (b) shows the free energy of oxide formation against temperature. (c) shows the rate of oxidation of metals against temperature. - correct answer (b) shows the free energy of oxide formation against temperature. ...

When does metamorphism occur? What does metamorphism include? Meta. rocks compare to Ig. and Sed. rocks? Does Metamorphism have a solid/not solid state? What are these two types of changes? - ANSWERSOccurs at elevated temperature and pressure, typically at the base of mountains Includes Recrystallization, making new minerals from original minerals, and sometimes, changes in the texture of the Parent Rock (protolith). Metamorphic rocks are organized compared to Igneous and Sedim...

Earth Science Final Exam Questions and Answers Latest 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 Longitude line...