Lab 2: Acid/Base Properties of an Antimicrobial Agent

Question 1

The safety precaution that should be taken before heating glassware

Answer 1

Check the glassware for cracks

Question 2

After synthesizing an isolating a known compound, a student is asked to leave it in his drawer until the next lab period. Which information is least necessary to include on the compound’s label?

Answer 2

the melting point of the compound

name is most important

Question 3

Suppose that the lab instructor does not give specific instructions regarding the disposal of the product synthesized in an experiment. What should you do?

Answer 3

Ask the lab instructor for disposal instructions

Question 4

The product of a synthesis with a theoretical yield of 10g is dried in an oven and the mass is measured once every hour. What is the closeness of consecutive mass measurements where the compound is dried to constant mass?

Answer 4

within a few milligrams

Question 5

An experimental procedure calls for the removal of the supernatant produced by a reaction. What is the definition of the supernatant?

Answer 5

The supernatant in the liquid portion of a heterogenous solid-liquid mixture

Question 6

What is a quantitative transfer?

Answer 6

Completely transfer all of the material from one container to another

Question 7

What is the correct formula for the hydronium ion?

Answer 7

H3O+

Question 8

What is the correct relationship between the hydronium ion concentration of a solution and the pH of that solution?

Answer 8

As the concentration of hydronium ion increases, the solution pH decreases

Question 9

Which of the given procedures is the best way to confirm that an aqueous solution is acidic?

Answer 9

Use a clean stirring rod to add a drop of the solution to a piece of blue litmus paper

Question 10

Benzoic acid has limited solubility in water. What is the best way to increase its solubility?

Answer 10

Add a base

Question 11

How many moles of benzoic acid are soluble in 130mL of water at room temp?

Answer 11

130mL x (0.34g/100mL) x (1mol / 122.12g) = .0036 mol

Question 12

In the reaction of sodium benzoate with hydrochloric acid to form benzoic acid, if one started with 18.9 mmol of sodium benzoate, how many grams of benzoic acid should be formed?

Answer 12

18.9 mmol x (1mol/1000mmol) x (122.12g/mol) = 2.31g

Question 13

The mass of a reaction product is found to exceed the mass of the calculated theoretical yield. What is the reason for this?

Answer 13

The product contains residual solvent