Deck 1: Basic Laboratory Principles and Techniques

Question 1

Suppose you are setting up an assay in which patient samples are run in duplicate.All duplicate patient results match except for one.Which of the following would be a reasonable explanation (or explanations) for the lack of reproducibility for the patient results?

A)The pipet tip for one of the patient analyses was not placed tightly on the micropipet.
B)The patient sample was "wicked" out when wiping the pipet tip.
C)The technologist did not depress the piston of the micropipet to the second stop when delivering patient sample in one of the analyses.
D)All of the above

Answer 1

All of the above

Question 2

According to the Hazards Identification System developed by NFPA, the blue diamond indicates:

A)the reactivity-stability hazard of the chemical
B)any special hazard information about the chemical
C)the flammability hazard of the chemical
D)the health hazard associated with the chemical

Answer 2

the health hazard associated with the chemical

Question 3

How many mL of 0.819 M acetic acid (MW = 60; pKₐ = 4.76) should be added to 350 mL of 0.368 M sodium acetate (MW = 82) to produce a final pH of 4.89?

A)95.41 mL
B)116.5 mL
C)128.8 mL
D)130.6 mL

Answer 3

116.5 mL

Question 4

A material that is used to absorb and remove water from the air is known as a:

A)teratogen
B)desiccant
C)carcinogen
D)reference material

Question 5

Sodium azide is used in small amounts as a preservative in laboratory reagents.What is the safety concern associated with sodium azide?

A)it can become explosive
B)it can become volatile
C)it is an environmental hazard
D)it acts as a strong acid

Question 6

The units for specific gravity are:

A)g/mL
B)mol/L
C)mg/L
D)%

Question 7

What is the molarity (M) of a solution prepared by placing 10 g of NaOH (MW = 40) in a flask and diluting to 500 mL?

A)0.25 M
B)0.5 M
C)1.0 M
D)2.5 M

Question 8

How many mL of a 17.6 % solution of compound X (MW 142) would be required to prepare 450 mL of a 0.75 M solution?

A)1.24 mL
B)142 mL
C)176 mL
D)272 mL

Question 9

Pipets that must be rinsed in order to deliver the measured volume are known as ______ pipets.Pipets that deliver the measured volume without rinsing are known as ______ pipets.______ pipets are not to be blown out when delivering the full volume of the pipet.

A)to contain (TC), to deliver (TD), serological
B)to contain (TC), to deliver (TD), volumetric
C)to deliver (TD), to contain (TC), serological
D)to deliver (TD), to contain (TC), volumetric

Question 10

Which laboratory glassware should be selected to ensure accuracy in the preparation of a 100 mL of 0.5 N HCl solution?

A)a beaker
B)a graduated cylinder
C)an Erlenmeyer flask
D)a volumetric flask

Question 11

Which of the following water purification techniques is most effective in removing dissolved ionized gases?

A)distillation
B)deionization
C)reverse osmosis
D)ultrafiltration

Question 12

What dilution is necessary to make an 18 mg/L solution from a 30 mg/L solution?

A)1:5 dilution
B)3:5 dilution
C)2:3 dilution
D)1:3 dilution

Question 13

A solution of unknown concentration of compound X (MW = 150) has an absorbance of 0.600.It had an absorbance of 0.300 at a concentration of 9 mg/dL.What is the molarity of the solution?

A)0.0012 M
B)0.18 M
C)1.2 M
D)18 M

Question 14

Which of the following laboratory containers should be selected to store an organic hydrocarbon solvent?

A)borosilicate glass
B)polyethylene
C)polycarbonate
D)polyvinyl chloride (PVC)

Question 15

How many mL of a 10 mg/L solution must be diluted to 100 mL to produce 100 mL of a 0.1 mg/dL solution?

A)1 mL
B)5 mL
C)10 mL
D)50 mL

Question 16

In the metric system, 1 L is equal to how many fL?

A)10-12
B)10-15
C)1012
D)1015

Question 17

The force produced by centrifugation is relative centrifugal force (RCF).The units for RCF are expressed as:

A)rpm
B)radius
C)number of times greater than gravity
D)there are no units for RCF

Question 18

A fire associated with actively operating electrical equipment is classified as a ______ fire.The most appropriate type of fire extinguisher for this type of fire would be ______.

A)Class A, halotron
B)Class B, carbon dioxide
C)Class C, halotron
D)Class A and B, dry chemical

Question 19

How would you prepare 400 mL of 0.85% NaCl?

A)place 0.85 g of NaCl in a flask and dilute to 400 mL
B)place 3.4 g of NaCl in a flask and dilute to 400 mL
C)place 8.5 g of NaCl in a flask and dilute to 400 mL
D)place 34 g of NaCl in a flask and dilute to 400 mL

Question 20

Taring an electronic balance refers to:

A)verifying balance performance using Class S weights
B)leveling the balance by adjusting the foot screws
C)zeroing the weight of the weighing vessel
D)adding counterweights to determine the true weight of the material being measured