tarted: Jan 29 at 8:24pm Quiz Instructions Make sure you have read the material\

Question

tarted: Jan 29 at 8:24pm Quiz Instructions Make sure you have read the material's) described on the module page before you take the quiz. Have yo materials with you when you take the quiz. The quiz is open notes/book, three attempts, each attempt is 0 minutes. The purpose of the quiz is to prepare you for lab from a conceptual, procedural and a safety oint of view. We work with strong acids and bases as well as expensive glassware. An unprepared stude a safety hazard to themselves as well as to their classmates. You MUST pass the quiz (70.00%) to come o lab.If you have not passed the quiz before lab you will not be able to attend. You need to contact Dr ishback as soon as possible r. Fishback you will get a zero for the lab. to discuss your options. If you do not come to lab and do not have a plan wit DQuestion 1 2 pts You receive a compound and are told it is N-bromosuccinimide(MP:175-180), but are also told it is impure. How could you tell this from a melting point test? O If the melting point is broad, it's impure. No idea. Impurities have no impact on melting point. If the melting point is lower than that of literature, it's impure. If the melting point is lower than that of literature and broad, it's impure. O

Explanation / Answer

question 1:

answer:if the melting point is lawer than the literature and broad it is impure.

The melting point of a substance decreases with increase in presence of impurities in it.Foreign substances in a crystalline solid disrupt the repeating pattern of forces that holds the solid together. So a smaller amount of energy is required to melt the part of the solid surrounding the impurity.A broad melting point is often an indication of an impure material (contaminated, not 100% pure).

question:4

Answer: True

In alcohol, R-OH group is present. In this molecule, oxygen atom has two lone pairs of electrons. Hence, the hydrogen atom of one molecule will get attracted towards the lone pair of another molecule. In this way, the hydrogen bonding will take place in alcohol.

Question :7

Answer: False

You should follow instructions and amount of chemicals as described in the procedure

question:6

answer: True

Solvation, also sometimes called dissolution, is the process of attraction and association of molecules of a solvent with molecules or ions of a solute. As ions dissolve in a solvent they spread out and become surrounded by solvent molecules. Solvation is the process of surrounding solute with solvent. It involves evening out a concentration gradient and evenly distributing the solute within the solvent.

question :10

Answer: Pick up the broken test tube and throw it in the trash

Question :5

Answer: lone pairs on oxygen and polarity of O-H bond

Polar molecules, such as watermolecules, have a weak, partial negative charge at one region of the molecule (the oxygen atom in water) and a partial positive charge elsewhere (the hydrogen atoms inwater).Thus when water molecules are close together, their positive and negative regions are attracted to the oppositely-charged regions of nearby molecules. The force of attraction, , is called a hydrogen bond

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