Evaluation

Question 1

How many significant figures does the universal gas constant (R=0.0821 L-atm/mol-K)?

Answer 1

infinite

Question 2

How many electrons can fit in the fourth main shell?

Answer 2

32

Question 3

Which does not correspond to the electron configuration of 1s2 2s2 2p6 3s2 3p6?

a. potassium ion
b. chloride ion
c. sulfide ion
d. none of the above

Answer 3

none of the above

Question 4

Which of the following elements has greater electron affinity than oxygen?

a. sulfure
b. carbon
c. neon
d. fluorine

Answer 4

fluorine

Question 5

Which molecular geometry has the greatest bond angle?
a. linear
b. tetrahedral
c. octahedral
d. trigonal bipyramidal

Answer 5

linear

Question 6

What is the name of the compound indicated below Pb(ClO)4?

Answer 6

plumbic hypochlorite

Question 7

What is the chemical formula of nitrous acid?

Answer 7

HNO2

Question 8

Alcohols and carboxylic acids have —OH groups. What type of chemical bonding occurs between the oxygen and hydrogen atoms?

a. ionic
b. polar covalent
c. hydrogen
d. non-polar covalent

Answer 8

polar covalent

Question 9

What is the other name for oil of vitriol?

Answer 9

sulfuric acid

Question 10

It is a result of instantaneous dipole in a non-polar molecule?
a. london dispersion force
b. dipole-dipole interaction
c. ion-dipole interaction
d. hydrogen bonding

Answer 10

london dispersion force

Question 11

Which among the following compounds has the lowest boiling point?
a. decanol
b. lauric acid
c. toluene
d. benzene

Answer 11

benzene

Question 12

What IMFA is/are present in the compound HC3(CH2)3CHO?
A. LDF only
B. DDI only
C. LDF and DDI
D. LDF, DDI, and HB

Answer 12

LDF and DDI

Question 13

A cylinder containing a gas is compressed to half its original volume. What will happen to its pressure at constant temperature?
A. doubled
B. halved
C. no effect
D. cannot be determined

Answer 13

doubled

Question 14

A 30-L gas initially has 110 kPa and 147°C. If its volume becomes 40 L and the pressure increased to 120 kPa, what is the new temperature (°C)?

Answer 14

338

Question 15

What is the pressure (atm) of hydrogen if it has 0.412 mol at 16°C in a 3.25 L?

Answer 15

3

Question 16

Balance the following chemical reaction:

H2O + MNO4- + Fe -> Fe3+ + Mn + OH-

Answer 16

12,3,7,7,3,24

Question 17

Potash alum is a common household substance that can be used as deodorant, aftershave treatment or styptic for minor bleeding from shaving. It is widely used as potassium sulfate dodecahydrate (KAl(SO4)2 12H2O). How many potassium atoms are there in 100 grams of potash alum?

Answer 17

1.27 x 10^23

Question 18

Nitrogen gas can be prepared by passing gaseous ammonia over solid copper (Il) oxide at high temperatures. The other products of the reaction are solid copper and water vapor as shown in the reaction below:

NH3 + CuO -> Cu + H2O

If 30.5 g of NH3 is reacted with 99.7 g of CuO, how much excess reactant will remain?

Answer 18

16.3g

Question 19

Nitrogen gas can be prepared by passing gaseous ammonia over solid copper (Il) oxide at high temperatures. The other products of the reaction are solid copper and water vapor as shown in the reaction below:

NH3 + CuO -> Cu + H2O

Based on the previous problem, how many grams of water vapor will be formed?

Answer 19

22.6g

Question 20

A white powder is analyzed and found to contain 43.64% phosphorus and 56.36% oxygen by mass. The compound has a molar mass of 283.88 g. What is the molecular formula of the compound?

Answer 20

P4O10

Question 21

How many grams of potassium dichromate is required to prepare 250 mL of 0.1 M solution of potassium dichromate?

Answer 21

7.35g

Question 22

A stock solution containing Mn2+ ions was prepared by dissolving 2.686 g of pure manganese metal in nitric acid and diluting to a final volume of 500 mL. From this stock solution, a volume of 10.00 mL was obtained and diluted to 250.0 mL. What is the molar concentration of the final solution?

Answer 22

3.911 x 10^-3 M

Question 23

A polar solute usually dissolves in a polar solvent and a nonpolar solute usually dissolves in a nonpolar solvent. This is?

Answer 23

the “like dissolves like” rule

Question 24

The synthesis of ammonia from nitrogen and hydrogen is an exothermic reaction. Which of the following will favor the formation of ammonia?

Answer 24

Decrease in temperature

Question 25

Under the Brønsted-Lowry concept of acids and bases, a base is a/an?

Answer 25

proton acceptor

Question 26

Determine the concentration of H+ ions in apple cider vinegar if the pH was measured to 3.57.

Answer 26

2.7 x 10^-4 M

Question 27

Buffer solutions are solutions that can neutralize small amounts of added acids and bases to maintain relatively stable pH values. Which of the following can be used to prepare a buffer solution?

Answer 27

NaHCOO, HCOOH000

Question 28

Determine the products of the acid-base reaction below: H2SO4 + Ca(OH)2 -> ______________________

Answer 28

CaSO4 + H2O

Question 29

What is the pH of a solution containing 0.02 M CH3COOH and 0.01 M NaCH3COO? Ka CH3COOH = 1.8 x 10^-5

Answer 29

4.44

Question 30

What is the molarity of 37% w/w hydrochloric acid? The density of 37% w/w HCl is 1.18 g/mL.

Answer 30

12M

Question 31

A type of analysis in terms of **sample size** that **can resolve fine-scale variations** in chemical elements, as well as determine the presence and distribution of different phases in materials.

Answer 31

micro

Question 32

An analyst determines that the analytical balance he used in a given analytical test is **wrongly calibrated**. Determine what type of error is represented.

Answer 32

systematic error

Question 33

It is a plot of an instrument's **readout vs. concentration**, the data for which are the results of measuring a series of standard solutions prepared for the experiment.

Answer 33

calibration curve

Question 34

It describes the **policies and procedures** the laboratory has to manage in relation to quality, or references where those procedures can be found. An essential requirement of ISO 9000 series of standards and ISO 17025.

Answer 34

quality manual

Question 35

It is a written program developed and implemented by the employer which sets forth procedures, equipment, PPE, and work practices that are capable of **protecting employees from the health hazard** presented by **hazardous chemicals** used in the workplace.

Answer 35

chemical hygiene plan

Question 36

This type of method consists of a set of instructions about how to carry out a method **issued by a national standards body and legislated** by the national government to become **mandatory**.

Answer 36

regulatory method

Question 37

In starting-up laboratory operations, the following should be observed except? A. Turning on the hoods, vents, and exhaust fans. B. Turning the equipment and instruments on. C. Performing analysis immediately. D. Monitoring operating parameters.

Answer 37

Performing analysis immediately.

Question 38

The following groups are known to be peroxide-forming compounds EXCEPT? A. Ethers with primary and/or secondary alkyl groups. B. Hydrocarbons with allylic, benzylic, or propargylic hydrogens. C. Conjugated dienes, eneynes, and diynes. D. All are peroxide-formers.

Answer 38

All are peroxide-formers.

Question 39

Which of the following is/are TRUE about the laboratory chemical hood? I. All work should be carried out at least 15 cm (6 in.) from the front edge of the hood. ll. Before each work, be sure that the hood exhaust system is functioning properly. Ill. Store hazardous chemicals inside the chemical hood to protect personnel from toxic fumes exposure. IV. The performance of laboratory chemical hood is highly dependent on its location.

Answer 39

I, II, and IV

Question 40

What hazards are represented by a GHS pictogram with a flame over circle symbol?

Answer 40

Oxidizers, organic peroxides

Question 41

It is a **hazardous waste characteristic** which applies to waste **liquids with a flash point less than 140°C** or **solids capable of spontaneous combustion** under normal temperature and pressure.

Answer 41

Ignitability

Question 42

What is the pH of an **acidic waste**?

Answer 42

pH ≤ 2

Question 43

This refers to a **person** who** produces hazardous wastes**, through any institutional, commercial, industrial, or trade activities.

Answer 43

waste generator

Question 44

The correct hierarchy of control principle (decreasing priority) from a chemical exposure perspective is? I. PPE ll. Engineering controls Ill. Administrative controls IV. Elimination V. Substitution

Answer 44

IV, V, II, III, I

Question 45

An **exposure limit** that indicates the **maximum average concentration** to which workers can safely be exposed for a normal 8-hr workday or 48-hr workweek.

Answer 45

Time weighted average (TWA)

Question 46

This refers to a **single sample or measurement** taken at specific time or over a short period as feasible.

Answer 46

grab sample

Question 47

The following are good sampling practices EXCEPT? A. Take several increments and composite them to form the sample. B. If possible, mix the material before getting the sample. C. Collect the sample in a container made of material that will chemically react with the sample. D. Sample frequently enough to allow for the identification of process cycles.

Answer 47

Collect the sample in a container made of material that will chemically react with the sample.

Question 48

Which of the following are TRUE about uncertainty? I. It is a difference between a single measurement or result and its true value. II. The range of possible values for a measurement. III. A measure of bias in a result or measurement. IV. It accounts for all errors (both determinate and indeterminate).

Answer 48

II and IV

Question 49

It is a graph showing the **time-dependent change** in the results of an analysis that is used to monitor whether an analysis is in a **state of statistical control**.

Answer 49

QC chart

Question 50

A clean sample (e.g. distilled water) processed through the instrumental steps or the measurement process to determine instrument contamination.

Answer 50

instrumental blank