the following absorbance data were obtained for a series standard solutions containing tannin using colorimetirc method: A = 0.014 (0.1 mg/L), A = 0.069 (1 mg/L), A = 0.145 (2 mg/L), A = 0.289 (4 mg/L), A = 0.442 (6 mg/L), A = 0.528 (8 mg/L). The intercept of the calibration equation is _____.

1- the following absorbance data were obtained for a series standard solutions containing tannin using colorimetirc method: A = 0.014 (0.1 mg/L), A = 0.069 (1 mg/L), A = 0.145 (2 mg/L), A = 0.289 (4 mg/L), A = 0.442 (6 mg/L), A = 0.528 (8 mg/L). The intercept of the calibration equation is _____. Using Excel if needed.
Question 2
1.
CH3-(CH2)4-C-O-H is an
Answer
aldehyde
phenol
acid
alcohol
3- The Contract Laboratory Program (CLP) was created under the program related to:
Answer
Superfund Act
Clean Water Act
Clean Air Act
Resource Conservation and Recovery Act
Question 4
1.
In which CFR (Code of Federal Regulations), you would be able to find methodologies for drinking water?
Answer
21 CFR 189
40 CFR 141
40 CFR 401
29 CFR 1900
5- Which of the following regulation in the U.S. is related to the 129 Priority Pollutant List (PPL)?
Answer
Resource Conservation and Recovery Act
Clean Air Act
Clean Water Act
Safe Drinking Water Act
Question 6
1.
For analytical results with = 26.17, SEM = 1.74, s = 4.26, n = 6, its Student’s t value to calculate confidence interval at 95% confidence level is:
Answer
2.571
2.015
1.943
2.447
7- Which of the following is considered as an appropriate unit in reporting pesticide concentration in soil sample?
Answer
ppmv
mg/m3
mg/kg
mg/L
8- The measurement of 5 replicates reveals an analyte’s concentration at 10.5, 10.2, 9.8, 9.7, and 10.4 mg/L. The standard error of mean (SEM) is _____ mg/L. Use Excel if needed.
Answer
Question 9
1.
Four analysts were given the same spiked sample containing 5.00 mg/L analyte, which one of the following analyst is the most accurate?
Answer
Analyst C: mean = 5.10 mg/L; s = 0.10 mg/L
Analyst B: mean = 4.95 mg/L; s = 0.20 mg/L
Analyst D: mean = 5.15 mg/L; s = 0.20 mg/L
Analyst A: mean = 4.90 mg/L; s = 0.10 mg/L
Question 10
1.
The group of chemicals that are solvent extractable and can generally be determined by chromatography such as phenol, phthalates, and PAHs and PCBs are defined as
Answer
VOCs
SVOCs
NVOCs
B/N
Question 11
1.
The measurement of 5 replicates reveals an analyte’s concentration at 10.5, 10.2, 9.8, 9.7, and 10.4 mg/L. The standard error is _____ mg/L. Use Excel if needed.
Answer
Question 12
1.
The following absorbance data were obtained for a series standard solutions containing tannin using colorimetirc method: A = 0.014 (0.1 mg/L), A = 0.069 (1 mg/L), A = 0.145 (2 mg/L), A = 0.289 (4 mg/L), A = 0.442 (6 mg/L), A = 0.528 (8 mg/L). The coefficient of determination (R2) of the calibration equation is _____ (Report R2 to 4 significant figures after the decimal point). Using Excel if needed.
Answer
Question 13
1.
The following set of censored data was obtained in drinking water with a detection limit of 1.0 µg/L for Cr(VI): 1.5 µg/L, 2.0 µg/L, N.D., 2.5 µg/L, 3.0 µg/L. As per U.S. EPA, the average concentration is best determined as:
Answer
(1.5 + 2.0 + 0 + 2.5 + 3.0)/5 = 1.8 µg/L
(1.5 + 2.0 + 2.5)/3 = 2.0 µg/L
(1.5 + 2.0 + 0.5 + 2.5 + 3.0)/4 = 1.9 µg/L
(1.5 + 2.0 + 2.5 + 3.0)/4 = 2.25 µg/L
Question 14
1.
Using z-test, an outlier is detected if its z-score is greater than:
Answer
2
3
4
6
Question 15
1.
Which of the following environmental data set is censored data?
Answer
1.5, 1.1, 1.3, 1.2, 1.0
1.5, 1.1, 1.2, 1.3, 1500
1.5, 1.1, 1.2, <0.5, 1.0
None of above
1 points
Question 16
1.
Contaminant concentration data show a normal distribution with mean of 100 mg/L and s = 10 mg/L. The probability of a measured concentration in the range of 80 mg/L and 120 mg/L is _____ (Reporting format: input 0.50 for 50%).
Answer
1 points
Question 17
1.
If a cut-off p-value of 0.01 is used, a significant linear regression can be stated if:
Answer
F < Fcritical
p = 0.045
R2 = 0.99
None of above
1 points
Question 18
1.
For analytical results with = 26.17, SEM = 1.74, s = 4.26, n = 6, its confidence interval at 95% confidence level is:
Answer
26.17 ± 4.47 = 21.70 ~ 30.64
26.17 ± 3.51 = 22.66 ~ 29.68
26.17 ± 4.26 = 21.91 ~ 30.43
26.17 ± 3.38 = 22.79 ~ 29.55
1 points
Question 19
1.
Four labs were undergone performance evaluation by the state environmental agency with the results of % recovery as follows: Lab A – 93%; Lab B – 95%; Lab C – 102%; Lab D – 105%. The true concentration of the test standard given by the third party was 10.0 mg/L. Which lab is the most accurate?
Answer
Lab A
Lab B
Lab C
Lab D
1 points
Question 20
1.
Which one of the following is the least favorable in treating the data point if it deviates from the rest of the data set?
Answer
Remove the data point simply because it is much larger (or smaller) than the other data points
Replace the data point with a new one after the error source has been identified
Retain the data point but using a more robust statistical tool to analyze the data
Exclude the data point using the outlier detection software
1 points
Question 21
1.
The probability of obtaining a sample with a concentration in the range of 8.5 to 9.5 ppm from a normally distributed population (μ = 8.5 ppm; σ2 = 0.25 ppm2) is:
Answer
0.3133
0.2881
0.5000
0.4772
1 points
Question 22
1.
The U.S. EPA defines MDL as "the minimum concentration measurable with _____ confidence that analyte's concentration is greater than zero".
Answer
95%
98%
99%
100%
1 points
Question 23
1.
Volatile organic compounds (VOCs) generally have boiling point of less than roughly:
Answer
50 0C
100 0C
200 0C
300 0C
1 points
Question 24
1.
The confidence interval of a normally distributed data with a mean ), standard deviation (s), and sample size (n) is:
Answer
± t ×s/n
± t ×s
± t ×s/
± s
1 points
Question 25
1.
The Ekman dredge sampler can be used for
Answer
Soft sediment
Compacted or vegetation-covered sediment
Rocky sediment
All of above
1 points