Orgo 1 Lab Final
Exp. 2 - Which of the following is used to separate aqueous and organic liquids? Buchner funnel separatory funnel separation tube separatory flask
separatory funnel
Exp. 1 - In the acid-base reaction from this experiment (experiment 1), what is the conjugate acid?
Benzoic Acid
Exp. 1 - Rank the following compounds in order of their increasing pKa (lowest pKa to highest): water, methane, benzoic acid, HCl
HCl, Benzoic Acid, water, methane
Exp. 3 - If the solubility of phenacetin is 1.22g/100mL solvent, how much solid (in grams) could be dissolved in 103 mL of solvent?
1.26 grams
Exp. 1 - Assuming the reaction goes to completion, what is the theoretical yield, in grams, of benzoic acid (in grams) when using 1.83 grams of sodium benzoate? (MW of sodium benzoate is 144.1 g/mol, MW of benzoic acid is 122.1 g/mol)
1.55
Exp. 2 - If you want to make 42 mL of 1 M NaOH solution, what mass (in grams) of NaOH would you need to dissolve? Use the molecular weight of NaOH as 40 g/mol
1.68
Exp. 3- What are some characteristics of a good solvent?
- does not chemically react with the solvent - when hot the solvent dissolves a lot of of the compound - volatile enough that the crystallized solid can be dried - completely dissolves impurities - inexpensive
Exp. 3 - what are some disadvantages of recrystallization?
- identifying the proper solvent can be difficult - products are somewhat soluble - product loss is inevitable.
Exp. 2 - Acetaminophen is the chemical name of what common drug?
tylenol
Exp. 3 - If you have 2.6g of an unknown, how much boiling water is needed to dissolve that substance? (solub. b.w. of unknown is 0.046 g/mL; density of water is 1.00 g/mL).
56.5 mL
Exp. 2 - What ingredient of Panacetin is the most acidic and most easily ionizable in the presence of a base? -sucrose -panacetin - acetylsalicylic acid -Sodium acetylsalicylate
Acetylsalicylic acid
Exp. 1 - Acetic acid is a weak acid. When acetic acid dissolves in water to make a solution, what is the major form of acid in the solution?
Acetic Acid
In Exp. 1, what is the most notable observable physical trait of the chemical reaction that signals its progress toward the product?
Change in state of matter
Exp. 1 - Imagine an organic liquid A has a density of 0.825 g/mL and liquid B has a density of 1.045 g/mL. If the two liquids were mixed (but are immiscible), which liquid would be on bottom?
Liquid B
Exp. 1 - If a student added HCl(aq) to sodium benzoate and stopped around pH 3 (instead of 2 as described in the lab procedure), how would this affect the % yield of this experiment?
Lower the % yield
Exp. 3 - If an impurity exists in a sample, the melting point _________ and ________.
Lowers and broadens
Exp. 1 - As in part B of exp. 1, when trying to determine the density of an unknown compound by graphing, what is recorded on the y-axis?
Mass
Exp. 1 - Drawing arrows to explain electron movement in organic chemistry is known as a (an):
Mechanism
Exp. 3 - In this experiment how did you determine the identity of the unknown?
Melting Points
Exp. 3 - what is one way to identify a compound using instrumental analysis? - NMR - Melting Point - Boiling Point - Density - Color
NMR
Exp. 3 - What results when too much solvent is used to dissolve the product in recrystallization?
Product loss - too much solvent dissolves more product
Exp. 3 - what purification method is used in this experiment?
Recrystallization
Exp. 3 - Why is it important to slowly cool the product after recrystallization?
allows perfect crystals to form and effectively reduces impurities
Exp. 2 - If methylene chloride has a density of 1.34 g/mL and was used in an extraction with an aqueous solution, which would be the top layer in the separatory funnel?
aqueous
Exp. 1 - Name two pieces of equipment essential for carrying out vacuum filtration
buchner funnel and side-arm flask
Exp. 2 - Which of the following outcomes would most possibly occur if you acidified sodium acetylsalicylate to pH 4 instead of pH 2?
falsely low % recovery of aspirin
Exp. 2 - Which of the following outcomes would most possibly occur if you initially dissolved the panacetin mixture in a more polar organic solvent, still immiscible in water, instead of dichloromethane?
falsely low % recovery of sucrose
